Adalm1000_Battery_SMU/MainCode/adalm1000_logger.py

# -*- coding: utf-8 -*-
import os
import time
import csv
import threading
import traceback
from datetime import datetime
import numpy as np
import matplotlib
import subprocess
import logging
import sys
from usb.core import USBError
matplotlib.use('Qt5Agg')
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
from collections import deque
from queue import Queue, Full, Empty

from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout, QHBoxLayout, 
                            QGridLayout, QLabel, QPushButton, QLineEdit, QCheckBox, 
                            QFrame, QMessageBox, QFileDialog, QComboBox)
from PyQt5.QtCore import Qt, QTimer, pyqtSignal, pyqtSlot, QObject, QThread
from PyQt5.QtGui import QDoubleValidator
from PyQt5 import sip
from PyQt5.QtCore import pyqtSignal
import pysmu
from pysmu import Session

import matplotlib as mpl
mpl.rcParams['font.family'] = 'sans-serif'
mpl.rcParams['font.sans-serif'] = ['DejaVu Sans', 'Arial', 'Liberation Sans', 'Verdana']  # Fallback fonts
mpl.rcParams['axes.edgecolor'] = '#D8DEE9'
mpl.rcParams['text.color'] = '#D8DEE9'
mpl.rcParams['axes.labelcolor'] = '#D8DEE9'
mpl.rcParams['xtick.color'] = '#D8DEE9'
mpl.rcParams['ytick.color'] = '#D8DEE9'

logging.getLogger('matplotlib.font_manager').setLevel(logging.WARNING)
logging.basicConfig(
    level=logging.DEBUG,
    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s",
    handlers=[
        logging.StreamHandler(sys.stdout),
        logging.FileHandler("adalm_debug.log", mode="a")
    ]
)
logger = logging.getLogger("adalm")

class DeviceDisconnectedError(Exception):
    pass

class DeviceManager:
    def __init__(self, session=None, dev=None, serial=None):
        self.session = session
        self.dev = dev
        self.serial = serial
        self.measurement_thread = None
        self.lock = threading.RLock()   # reentrant lock
        self._last_open_attempt = 0
        logger.info(f"Created DeviceManager for {serial}")
        mpl.font_manager._get_font.cache_clear() 
        self.measurement_thread = MeasurementThread(self, 0.1, self)

        # Initialize data buffers and statistics
        self.time_data = deque(maxlen=10000)
        self.voltage_data = deque(maxlen=10000)
        self.current_data = deque(maxlen=10000)
        self.display_time_data = deque(maxlen=1000)
        self.display_voltage_data = deque(maxlen=1000)
        self.display_current_data = deque(maxlen=1000)
        self.capacity_ah = 0.0
        self.energy = 0.0
        self.charge_capacity = 0.0
        self.coulomb_efficiency = 0.0
        self.cycle_count = 0
        self.test_phase = "Idle"
        
        # Add these new attributes for recording state
        self.start_time = time.time()  # Initialize with current time
        self.last_update_time = self.start_time
        self.is_recording = False
        self.log_file = None
        self.log_writer = None
        self._last_log_time = 0
        self.log_dir = os.path.expanduser("~/adalm1000/logs")
        os.makedirs(self.log_dir, exist_ok=True)
        self.start_time = None
        self.last_measurement_time = None

    def reset_data(self):
        """Reset all data buffers and statistics for the device"""
        self.time_data.clear()
        self.voltage_data.clear()
        self.current_data.clear()
        self.display_time_data.clear()
        self.display_voltage_data.clear()
        self.display_current_data.clear()
        self.capacity_ah = 0.0
        self.energy = 0.0
        self.charge_capacity = 0.0
        self.coulomb_efficiency = 0.0
        self.cycle_count = 0
        self.test_phase = "Idle"
        # Reset recording state
        self.is_recording = False
        self._last_log_time = 0

    def safe_call(self, fn, *args, **kwargs):
        """Call fn under device lock and handle USB errors."""
        with self.lock:
            try:
                return fn(*args, **kwargs)
            except (USBError, OSError, pysmu.exceptions.USBError) as e:
                logger.exception(f"USB error in safe_call for {self.serial}")
                raise DeviceDisconnectedError(f"USB error: {e}") from e
            except Exception as e:
                logger.exception(f"Error in safe_call for {self.serial}")
                raise

    def set_simv_current(self, current):
        """Set channel A to SIMV and apply current."""
        def _do():
            chA = self.dev.channels['A']
            if hasattr(chA, 'Mode'):
                try:
                    chA.mode = chA.Mode.SIMV
                except Exception:
                    logger.debug("Couldn't set chA.mode to SIMV")
            if hasattr(chA, 'constant'):
                chA.constant(abs(current))
            else:
                try:
                    chA.set_current(abs(current))
                except Exception:
                    logger.debug("No channel.constant or set_current available")
        logger.debug(f"Device {self.serial}: set_simv_current {current}")
        return self.safe_call(_do)

    def hi_z(self):
        def _do():
            chA = self.dev.channels['A']
            if hasattr(chA, 'Mode'):
                try:
                    chA.mode = chA.Mode.HI_Z
                except Exception:
                    logger.debug("Couldn't set chA.mode to HI_Z")
            if hasattr(chA, 'constant'):
                chA.constant(0)
        logger.debug(f"Device {self.serial}: hi_z()")
        return self.safe_call(_do)

    def close(self):
        """Close session/device references safely."""
        with self.lock:
            try:
                if self.dev:
                    try:
                        if hasattr(self.dev, 'close'):
                            self.dev.close()
                    except Exception:
                        logger.exception(f"Error closing device {self.serial}")
                    self.dev = None
                if self.session:
                    try:
                        if hasattr(self.session, 'close'):
                            self.session.close()
                    except Exception:
                        logger.exception(f"Error closing session for {self.serial}")
                    self.session = None
            except Exception:
                logger.exception(f"Error in DeviceManager.close for {self.serial}")

    def reopen_with_backoff(self, max_attempts=5, base_delay=1.0):
        """Try to reopen the device with exponential backoff."""
        now = time.time()
        if now - self._last_open_attempt < 0.2:
            time.sleep(0.2)
        self._last_open_attempt = now

        for attempt in range(1, max_attempts + 1):
            try:
                logger.info(f"Attempting to reopen device {self.serial} (attempt {attempt}/{max_attempts})")
                from pysmu import Session
                s = Session()
                devs = s.list_devices()
                chosen = None
                for d in devs:
                    try:
                        if hasattr(d, 'serial') and d.serial == self.serial:
                            chosen = s.open(d.serial)
                            break
                        if isinstance(d, (list, tuple)) and str(d[0]) == str(self.serial):
                            chosen = s.open(str(d[0]))
                            break
                    except Exception:
                        continue
                if chosen is None and devs:
                    logger.warning(f"Could not find serial {self.serial}; opening first device")
                    chosen = s.open(devs[0].serial if hasattr(devs[0], 'serial') else str(devs[0][0]))
                if chosen:
                    with self.lock:
                        try:
                            if self.dev and hasattr(self.dev, 'close'):
                                self.dev.close()
                        except Exception:
                            logger.exception("Error closing previous dev")
                        self.session = s
                        self.dev = chosen
                        logger.info(f"Reopened device {self.serial} OK")
                    return True
            except Exception as e:
                logger.exception(f"Reopen attempt {attempt} failed for {self.serial}: {e}")
            time.sleep(base_delay * attempt)
        logger.error(f"Failed to reopen device {self.serial} after {max_attempts} attempts")
        return False

class MeasurementThread(QThread):
    update_signal = pyqtSignal(str, float, float, float)
    error_signal = pyqtSignal(str)
    
    def __init__(self, device_manager, interval, parent_manager):
        super().__init__()
        self.dev_manager = device_manager 
        self.interval = interval
        self._running = True
        self.filter_window_size = 10
        self.voltage_window = []
        self.current_window = []
        self.start_time = None
        self.measurement_queue = Queue(maxsize=1)
        self.current_direction = 1
        self.parent_manager = parent_manager
    
    def stop(self):
        self._running = False
        try:
            self.dev_manager.hi_z()
        except Exception as e:
            logger.error(f"Error stopping device: {e}")
        self.wait(500)

    def run(self):
        logger.info(f"MeasurementThread STARTED for {self.parent_manager.serial}")
        if not self.dev_manager.dev:
            logger.error("No device available")
            self.error_signal.emit("Device not initialized")
            return

        # Initialize timing
        self.dev_manager.start_time = time.time()
        
        while self._running:
            try:
                start_time = time.time()
                
                # Get measurement
                samples = self.dev_manager.dev.get_samples(1)
                if not samples:
                    time.sleep(0.01)
                    continue
                    
                sample = samples[0]
                voltage = sample[0][0]
                current = sample[0][1]
                current_time = time.time()
                
                # Validate before sending
                if not (0 <= voltage <= 5.0) or not (-0.2 <= current <= 0.2):
                    continue
                    
                # Emit update
                self.update_signal.emit(
                    self.parent_manager.serial,
                    voltage,
                    current,
                    current_time
                )
                
                # Maintain precise timing
                elapsed = time.time() - start_time
                sleep_time = max(0.001, self.interval - elapsed)
                time.sleep(sleep_time)
                
            except (USBError, pysmu.exceptions.USBError) as e:
                logger.error(f"USB Error: {str(e)}")
                self.error_signal.emit("USB communication error")
                time.sleep(1)
                
            except Exception as e:
                logger.error(f"Measurement error: {str(e)}")
                time.sleep(0.5)

    def _do_measure_once(self):
        """Actual measurement code protected by DeviceManager lock"""
        # This will be called inside DeviceManager.safe_call
        samples = self.dev_manager.dev.get_samples(1)
        if samples:
            sample = samples[0]
            voltage = sample[0][0]  # Channel A voltage
            current = sample[0][1]  # Channel A current
            return voltage, current, time.time()
        return 0, 0, time.time()

    def set_direction(self, direction):
        self.current_direction = direction

class TestSequenceWorker(QThread):
    finished = pyqtSignal()
    update_phase = pyqtSignal(str)
    update_status = pyqtSignal(str)
    test_completed = pyqtSignal()
    error_occurred = pyqtSignal(str)

    def __init__(self, device_manager, test_current, charge_cutoff, discharge_cutoff,
                 rest_time_hours, continuous_mode, parent=None):
        super().__init__(parent)
        self.dev_manager = device_manager              # DeviceManager instance
        self.device = device_manager.dev               # raw pysmu device for direct calls
        self.test_current = float(test_current)
        self.charge_cutoff = float(charge_cutoff)
        self.discharge_cutoff = float(discharge_cutoff)
        self.rest_time = float(rest_time_hours) * 3600.0
        self.continuous_mode = bool(continuous_mode)
        self.parent = parent
        self._running = True
        self.voltage_timeout = 0.5

    def stop(self):
        self._running = False

    def _set_direction_on_measurement_thread(self, direction):
        try:
            mt = getattr(self.dev_manager, 'measurement_thread', None)
            if mt and hasattr(mt, 'set_direction'):
                mt.set_direction(direction)
        except Exception:
            pass

    def _set_simv_current(self, current):
        try:
            self.dev_manager.set_simv_current(current)
        except DeviceDisconnectedError:
            logger.error("Device disconnected during current set")
            raise

    def _hi_z(self):
        try:
            self.dev_manager.hi_z()
        except DeviceDisconnectedError:
            logger.error("Device disconnected during hi-z")
            raise

    def get_latest_measurement(self):
        try:
            q = self.dev_manager.measurement_thread.measurement_queue
            item = q.get(timeout=self.voltage_timeout)
            # support multiple formats
            if isinstance(item, (tuple, list)):
                if len(item) >= 3 and isinstance(item[0], str):
                    _, v, i, *rest = item
                    ts = rest[0] if rest else None
                    return v, i, ts
                elif len(item) >= 2:
                    v = item[0]; i = item[1]; ts = item[2] if len(item) >= 3 else None
                    return v, i, ts
            return None, None, None
        except Empty:
            return None, None, None
        except Exception:
            return None, None, None

    def charge_phase(self):
        self.update_phase.emit("Charge")
        self._set_direction_on_measurement_thread(1)
        self._set_simv_current(abs(self.test_current))
        while self._running:
            v, i, ts = self.get_latest_measurement()
            if v is None:
                time.sleep(0.05); continue
            if v >= self.charge_cutoff:
                break
            time.sleep(0.1)
        self._hi_z()

    def discharge_phase(self):
        self.update_phase.emit("Discharge")
        self._set_direction_on_measurement_thread(-1)
        self._set_simv_current(-abs(self.test_current))
        while self._running:
            v, i, ts = self.get_latest_measurement()
            if v is None:
                time.sleep(0.05); continue
            if v <= self.discharge_cutoff:
                break
            time.sleep(0.1)
        self._hi_z()

    def rest_phase(self, phase_name):
        self.update_phase.emit(f"Rest: {phase_name}")
        rest_end = time.time() + self.rest_time
        while time.time() < rest_end and self._running:
            time.sleep(0.5)
            self.update_status.emit(f"Resting | {phase_name} | {max(0, rest_end-time.time()):.0f}s left")

    def run(self):
        try:
            while self._running:
                self.discharge_phase()
                if not self._running: break
                if self.rest_time > 0: self.rest_phase("Post-Discharge")
                if not self._running: break
                self.charge_phase()
                if not self._running: break
                if self.rest_time > 0: self.rest_phase("Post-Charge")
                if not self.continuous_mode:
                    break
            self.test_completed.emit()
        except Exception as e:
            self.error_occurred.emit(str(e))
        finally:
            try: self._hi_z()
            except: pass
            self.finished.emit()

class DischargeWorker(QThread):
    finished = pyqtSignal()
    update_status = pyqtSignal(str)
    test_completed = pyqtSignal()
    error_occurred = pyqtSignal(str)

    def __init__(self, device_manager, discharge_current, cutoff_voltage, parent=None):
        super().__init__(parent)
        self.dev_manager = device_manager
        self.device = device_manager.dev
        self.discharge_current = float(discharge_current)
        self.cutoff_voltage = float(cutoff_voltage)
        self._running = True
        self.voltage_timeout = 0.5

    def stop(self):
        self._running = False

    def _set_direction_on_measurement_thread(self, direction):
        try:
            mt = getattr(self.dev_manager, 'measurement_thread', None)
            if mt and hasattr(mt, 'set_direction'):
                mt.set_direction(direction)
        except Exception:
            pass

    def _set_simv_current(self, current):
        try:
            self.dev_manager.set_simv_current(current)
        except DeviceDisconnectedError:
            logger.error("Device disconnected during current set")
            raise

    def _hi_z(self):
        try:
            self.dev_manager.hi_z()
        except DeviceDisconnectedError:
            logger.error("Device disconnected during hi-z")
            raise

    def get_latest_measurement(self):
        try:
            q = self.dev_manager.measurement_thread.measurement_queue
            item = q.get(timeout=self.voltage_timeout)
            if isinstance(item, (tuple, list)):
                if len(item) >= 3 and isinstance(item[0], str):
                    _, v, i, *rest = item; ts = rest[0] if rest else None; return v, i, ts
                elif len(item) >= 2:
                    v = item[0]; i = item[1]; ts = item[2] if len(item)>=3 else None; return v, i, ts
            return None, None, None
        except Empty:
            return None, None, None
        except Exception:
            return None, None, None

    def run(self):
        try:
            self._set_direction_on_measurement_thread(-1)
            self._set_simv_current(-abs(self.discharge_current))
            while self._running:
                v, i, ts = self.get_latest_measurement()
                if v is None:
                    time.sleep(0.05); continue
                if v <= self.cutoff_voltage:
                    break
                time.sleep(0.1)
            self.test_completed.emit()
        except Exception as e:
            self.error_occurred.emit(str(e))
        finally:
            try: self._hi_z()
            except: pass
            self.finished.emit()

class ChargeWorker(QThread):
    finished = pyqtSignal()
    update_status = pyqtSignal(str)
    test_completed = pyqtSignal()
    error_occurred = pyqtSignal(str)

    def __init__(self, device_manager, charge_current, cutoff_voltage, parent=None):
        super().__init__(parent)
        self.dev_manager = device_manager
        self.device = device_manager.dev
        self.charge_current = float(charge_current)
        self.cutoff_voltage = float(cutoff_voltage)
        self._running = True
        self.voltage_timeout = 0.5

    def stop(self):
        self._running = False

    def _set_direction_on_measurement_thread(self, direction):
        try:
            mt = getattr(self.dev_manager, 'measurement_thread', None)
            if mt and hasattr(mt, 'set_direction'):
                mt.set_direction(direction)
        except Exception:
            pass

    def _set_simv_current(self, current):
        try:
            self.dev_manager.set_simv_current(current)
        except DeviceDisconnectedError:
            logger.error("Device disconnected during current set")
            raise

    def _hi_z(self):
        try:
            self.dev_manager.hi_z()
        except DeviceDisconnectedError:
            logger.error("Device disconnected during hi-z")
            raise

    def get_latest_measurement(self):
        try:
            q = self.dev_manager.measurement_thread.measurement_queue
            item = q.get(timeout=self.voltage_timeout)
            if isinstance(item, (tuple, list)):
                if len(item) >= 3 and isinstance(item[0], str):
                    _, v, i, *rest = item; ts = rest[0] if rest else None; return v, i, ts
                elif len(item) >= 2:
                    v = item[0]; i = item[1]; ts = item[2] if len(item)>=3 else None; return v, i, ts
            return None, None, None
        except Empty:
            return None, None, None
        except Exception:
            return None, None, None

    def run(self):
        try:
            self._set_direction_on_measurement_thread(1)
            self._set_simv_current(abs(self.charge_current))
            while self._running:
                v, i, ts = self.get_latest_measurement()
                if v is None:
                    time.sleep(0.05); continue
                if v >= self.cutoff_voltage:
                    break
                time.sleep(0.1)
            self.test_completed.emit()
        except Exception as e:
            self.error_occurred.emit(str(e))
        finally:
            try: self._hi_z()
            except: pass
            self.finished.emit()
            
class BatteryTester(QMainWindow):
    def __init__(self):
        self.plot_mutex = threading.Lock()
        super().__init__()
        
        self.devices = {}
        self.active_device = None
        self.last_logged_phase = None
        self.global_recording = False
        self.debug_counter = 0 
        self.last_debug_time = time.time()

        # Color scheme - MUST BE DEFINED FIRST
        self.bg_color = "#2E3440"
        self.fg_color = "#D8DEE9"
        self.accent_color = "#5E81AC"
        self.warning_color = "#BF616A"
        self.success_color = "#A3BE8C"
        
        # Status colors - MUST BE DEFINED BEFORE init_device()
        self.status_colors = {
            "connected": "green",
            "disconnected": "red",
            "error": "orange", 
            "active": self.accent_color,
            "warning": self.warning_color
        }
        
        # Device and measurement state
        self.session_active = False
        self.measuring = False
        self.test_running = False
        self.continuous_mode = False  
        self.request_stop = False  
        self.interval = 0.1  
        self.log_dir = os.path.expanduser("~/adalm1000/logs")
        os.makedirs(self.log_dir, exist_ok=True)
                
        # Data buffers
        self.aggregation_buffer = {
            'time': [], 'voltage': [], 'current': [], 
            'count': 0, 'last_plot_time': 0
        }
        self.phase_data = deque()
        self.downsample_factor = 1  # Initial kein Downsampling
        self.downsample_counter = 0

         # Initialize all measurement variables
        self.capacity_ah = 0.0
        self.energy = 0.0
        self.charge_capacity = 0.0
        self.coulomb_efficiency = 0.0
        self.cycle_count = 0
        self.start_time = time.time()
        self.last_update_time = self.start_time

        self.capacity = 1.0
        self.c_rate = 0.1
        self.charge_cutoff = 1.43
        self.discharge_cutoff = 0.01
        self.rest_time = 0.5
        
        # Initialize UI and device
        self.setup_ui()
        self.init_device()
        self.current_mode = "Live Monitoring"  
        self.change_mode(self.current_mode)
        
        # Set window properties
        self.setWindowTitle("ADALM1000 - Battery Tester (Multi-Mode)")
        self.resize(1000, 800)
        self.setMinimumSize(800, 700)
        
        # Status update timer
        self.status_timer = QTimer()
        self.status_timer.timeout.connect(self.update_status_and_plot)
        self.status_timer.start(1000) #every second

    def print_device_status(self):
        """Debug method to print current device states"""
        for serial, device in self.devices.items():
            print(f"\nDevice: {serial}")
            print(f"Active: {device == self.active_device}")
            print(f"Start Time: {getattr(device, 'start_time', 'NOT SET')}")
            print(f"Data Points: {len(device.time_data)}")
            print(f"Last Voltage: {device.voltage_data[-1] if device.voltage_data else 'NONE'}")
            print(f"Thread Running: {device.measurement_thread.isRunning() if hasattr(device, 'measurement_thread') else 'NO THREAD'}")
            
    def setup_ui(self):
        """Configure the user interface with all elements properly organized"""
        # Main widget and layout
        self.central_widget = QWidget()
        self.setCentralWidget(self.central_widget)
        self.main_layout = QVBoxLayout(self.central_widget)
        self.main_layout.setContentsMargins(8, 8, 8, 8)
        self.main_layout.setSpacing(8)
        
        # Base style for consistent sizing
        base_style = f"""
            font-size: 10pt;
            color: {self.fg_color};
        """
        
        # Mode and device selection frame
        mode_frame = QFrame()
        mode_frame.setFrameShape(QFrame.StyledPanel)
        mode_frame.setStyleSheet(f"""
            QFrame {{
                border: 1px solid {self.accent_color};
                border-radius: 5px;
                padding: 5px;
            }}
            QLabel {base_style}
        """)
        mode_layout = QHBoxLayout(mode_frame)
        mode_layout.setContentsMargins(5, 2, 5, 2)
        
        # Test mode selection
        self.mode_label = QLabel("Test Mode:")
        mode_layout.addWidget(self.mode_label)

        self.mode_combo = QComboBox()
        self.mode_combo.addItems(["Live Monitoring", "Discharge Test", "Charge Test", "Cycle Test"])
        self.mode_combo.setStyleSheet(f"""
            QComboBox {{
                {base_style}
                background-color: #3B4252;
                border: 1px solid #4C566A;
                border-radius: 3px;
                padding: 2px;
                min-height: 24px;
            }}
        """)
        self.mode_combo.currentTextChanged.connect(self.change_mode)
        mode_layout.addWidget(self.mode_combo, 1)
        
        # Device selection
        self.device_label = QLabel("Device:")
        mode_layout.addWidget(self.device_label)

        self.device_combo = QComboBox()
        self.device_combo.setStyleSheet(f"""
            QComboBox {{
                {base_style}
                background-color: #3B4252;
                border: 1px solid #4C566A;
                border-radius: 3px;
                padding: 2px;
                min-height: 24px;
            }}
        """)
        self.device_combo.currentIndexChanged.connect(self.change_device)
        mode_layout.addWidget(self.device_combo, 1)
        
        self.main_layout.addWidget(mode_frame)
        
        # Header area
        header_frame = QFrame()
        header_frame.setFrameShape(QFrame.NoFrame)
        header_layout = QHBoxLayout(header_frame)
        header_layout.setContentsMargins(0, 0, 0, 0)
        
        self.title_label = QLabel("ADALM1000 Battery Tester")
        self.title_label.setStyleSheet(f"font-size: 14pt; font-weight: bold; color: {self.accent_color};")
        header_layout.addWidget(self.title_label, 1)
        
        # Status indicator
        self.status_light = QLabel()
        self.status_light.setFixedSize(16, 16)
        self.status_light.setStyleSheet("background-color: red; border-radius: 8px;")
        header_layout.addWidget(self.status_light)
        
        self.connection_label = QLabel("Disconnected")
        self.connection_label.setStyleSheet(base_style)
        header_layout.addWidget(self.connection_label)
        
        # Reconnect button
        self.reconnect_btn = QPushButton("Reconnect")
        self.reconnect_btn.setStyleSheet(f"""
            {base_style}
            background-color: #4C566A;
            padding: 2px 8px;
            border-radius: 3px;
            min-height: 24px;
        """)
        self.reconnect_btn.clicked.connect(self.reconnect_device)
        header_layout.addWidget(self.reconnect_btn)
        
        self.main_layout.addWidget(header_frame)

        # Measurement display - 4 rows x 2 columns
        display_frame = QFrame()
        display_frame.setFrameShape(QFrame.StyledPanel)
        display_frame.setStyleSheet(f"""
            QFrame {{
                border: 1px solid {self.accent_color}; 
                border-radius: 5px;
                padding: 3px;
            }}
            QLabel {base_style}
        """)
        display_layout = QGridLayout(display_frame)
        display_layout.setHorizontalSpacing(5)
        display_layout.setVerticalSpacing(2)
        display_layout.setContentsMargins(5, 3, 5, 3)

        # Measurement fields in exact order
        measurement_fields = [
            ("Voltage", "V"),       ("Current", "A"),
            ("Elapsed Time", "s"),  ("Energy", "Wh"),
            ("Test Phase", None),   ("Capacity", "Ah"),  # None for no unit
            ("Cycle Count", None),  ("Coulomb Eff.", "%")
        ]

        for i, (label, unit) in enumerate(measurement_fields):
            row = i // 2
            col = (i % 2) * 2
            
            # Container for each measurement with fixed height
            container = QWidget()
            container.setFixedHeight(24)  # Fixed row height
            container_layout = QHBoxLayout(container)
            container_layout.setContentsMargins(2, 0, 2, 0)
            container_layout.setSpacing(2)  # Minimal spacing between elements
            
            # Label (fixed width)
            lbl = QLabel(f"{label}:")
            lbl.setStyleSheet("min-width: 85px;")
            container_layout.addWidget(lbl)
            
            # Value field (fixed width)
            value_text = "0.000" if unit else ("Idle" if label == "Test Phase" else "0")
            value_lbl = QLabel(value_text)
            value_lbl.setAlignment(Qt.AlignRight)
            value_lbl.setStyleSheet("""
                font-weight: bold;
                min-width: 65px;
                max-width: 65px;
            """)
            container_layout.addWidget(value_lbl)
            
            # Unit (only if exists)
            if unit:
                unit_lbl = QLabel(unit)
                unit_lbl.setStyleSheet("min-width: 20px;")
                container_layout.addWidget(unit_lbl)
            
            display_layout.addWidget(container, row, col)

        # Assign references
        widgets = [
            display_layout.itemAtPosition(r, c).widget().layout().itemAt(1).widget()
            for r in range(4) for c in [0, 2]
        ]
        (self.voltage_label, self.current_label, 
        self.time_label, self.energy_label,
        self.phase_label, self.capacity_label,
        self.cycle_label, self.efficiency_label) = widgets

        self.main_layout.addWidget(display_frame)
        
        # Control area
        controls_frame = QFrame()
        controls_frame.setFrameShape(QFrame.NoFrame)
        controls_layout = QHBoxLayout(controls_frame)
        controls_layout.setContentsMargins(0, 0, 0, 0)
        
        # Parameters frame
        self.params_frame = QFrame()
        self.params_frame.setFrameShape(QFrame.StyledPanel)
        self.params_frame.setStyleSheet(f"""
            QFrame {{ 
                border: 1px solid {self.accent_color}; 
                border-radius: 5px;
            }}
            QLabel {base_style}
            QLineEdit {{
                {base_style}
                background-color: #3B4252;
                border: 1px solid #4C566A;
                border-radius: 3px;
                padding: 2px;
                min-height: 24px;
            }}
        """)
        self.params_layout = QGridLayout(self.params_frame)
        self.params_layout.setVerticalSpacing(3)
        self.params_layout.setHorizontalSpacing(5)
        self.params_layout.setContentsMargins(8, 5, 8, 5)
        
        # Add parameter inputs
        row = 0
        
        # Battery Capacity
        self.capacity_label_1 = QLabel("Capacity (Ah):")
        self.params_layout.addWidget(self.capacity_label_1, row, 0)
        
        self.capacity_input = QLineEdit("1.0")
        self.capacity_input.setValidator(QDoubleValidator(0.001, 100, 3))
        self.params_layout.addWidget(self.capacity_input, row, 1)
        row += 1
        
        # C-Rate
        self.c_rate_label = QLabel("C-Rate:")
        self.params_layout.addWidget(self.c_rate_label, row, 0)
        
        self.c_rate_input = QLineEdit("0.1")
        self.c_rate_input.setValidator(QDoubleValidator(0.01, 1, 2))
        self.params_layout.addWidget(self.c_rate_input, row, 1)
        row += 1
        
        # Charge Cutoff Voltage
        self.charge_cutoff_label = QLabel("Charge Cutoff (V):")
        self.params_layout.addWidget(self.charge_cutoff_label, row, 0)
        
        self.charge_cutoff_input = QLineEdit("1.43")
        self.charge_cutoff_input.setValidator(QDoubleValidator(0.1, 5.0, 3))
        self.params_layout.addWidget(self.charge_cutoff_input, row, 1)
        row += 1
        
        # Discharge Cutoff Voltage
        self.discharge_cutoff_label = QLabel("Discharge Cutoff (V):")
        self.params_layout.addWidget(self.discharge_cutoff_label, row, 0)
        
        self.discharge_cutoff_input = QLineEdit("0.01")
        self.discharge_cutoff_input.setValidator(QDoubleValidator(0.1, 5.0, 3))
        self.params_layout.addWidget(self.discharge_cutoff_input, row, 1)
        row += 1
        
        # Rest Time
        self.rest_time_label = QLabel("Rest Time (h):")
        self.params_layout.addWidget(self.rest_time_label, row, 0)
        
        self.rest_time_input = QLineEdit("0.5")
        self.rest_time_input.setValidator(QDoubleValidator(0.1, 24, 1))
        self.params_layout.addWidget(self.rest_time_input, row, 1)
        row += 1
        
        # Test Conditions
        self.test_conditions_label = QLabel("Test Conditions:")
        self.params_layout.addWidget(self.test_conditions_label, row, 0)
        
        self.test_conditions_input = QLineEdit("Room Temperature")
        self.params_layout.addWidget(self.test_conditions_input, row, 1)
        
        controls_layout.addWidget(self.params_frame, 1)

        # Button frame
        button_frame = QFrame()
        button_frame.setFrameShape(QFrame.NoFrame)
        button_layout = QVBoxLayout(button_frame)
        button_layout.setContentsMargins(5, 0, 0, 0)
        button_layout.setSpacing(5)
        
        # Button style
        button_style = f"""
            QPushButton {{
                {base_style}
                font-weight: bold;
                padding: 4px 8px;
                border-radius: 4px;
                min-height: 28px;
                color: {self.fg_color};
            }}
            QPushButton:checked {{
                background-color: {self.warning_color} !important;
                color: {self.fg_color} !important;
            }}
            QPushButton:disabled {{
                background-color: #4C566A;
            }}
        """
        
        # Single toggle button (Start/Stop)
        self.toggle_button = QPushButton("START")
        self.toggle_button.setCheckable(True)
        self.toggle_button.setStyleSheet(button_style + f"""
            background-color: {self.success_color};
            min-width: 120px;
        """)
        self.toggle_button.clicked.connect(self.toggle_test)
        button_layout.addWidget(self.toggle_button)
        
        # Continuous mode checkbox (only for Cycle mode)
        self.continuous_mode_check = QCheckBox("Continuous Mode")
        self.continuous_mode_check.setChecked(True)
        self.continuous_mode_check.setStyleSheet(base_style)
        button_layout.addWidget(self.continuous_mode_check)
        self.continuous_mode_check.hide()
        
        # Record button for Live mode
        self.record_button = QPushButton("● Start Recording")
        self.record_button.setCheckable(True)
        self.record_button.setStyleSheet(button_style.replace(
            "background-color", "background-color", 1
        ) + f"background-color: {self.success_color};")
        self.record_button.clicked.connect(self.toggle_global_recording)
        button_layout.addWidget(self.record_button)
        self.record_button.hide()
        
        controls_layout.addWidget(button_frame)
        self.main_layout.addWidget(controls_frame)
        
        # Plot area
        self.setup_plot()
        
        # Status bar
        self.status_bar = self.statusBar()
        self.status_bar.setStyleSheet(f"color: {self.fg_color}; font-size: 9pt;")
        self.status_bar.showMessage("Ready")

        # Apply dark theme
        self.setStyleSheet(f"""
            QMainWindow {{
                background-color: {self.bg_color};
            }}
            QWidget {{
                {base_style}
            }}
        """)
    
    def apply_button_style(self):
        """Apply consistent button styling based on current state"""
        if self.toggle_button.isChecked():
            # Stop state - red
            self.toggle_button.setStyleSheet(f"""
                QPushButton {{
                    background-color: {self.warning_color};
                    color: white;
                    font-weight: bold;
                    border: none;
                    border-radius: 4px;
                    padding: 4px 8px;
                    min-height: 28px;
                }}
                QPushButton:hover {{
                    background-color: #{self.darker_color(self.warning_color)};
                }}
            """)
        else:
            # Start state - green
            self.toggle_button.setStyleSheet(f"""
                QPushButton {{
                    background-color: {self.success_color};
                    color: {self.fg_color};
                    font-weight: bold;
                    border: none;
                    border-radius: 4px;
                    padding: 4px 8px;
                    min-height: 28px;
                }}
                QPushButton:hover {{
                    background-color: #{self.darker_color(self.success_color)};
                }}
            """)
            
        # Update record button separately
        if self.record_button.isChecked():
            self.record_button.setStyleSheet(f"""
                QPushButton {{
                    background-color: {self.warning_color};
                    color: white;
                    font-weight: bold;
                    border: none;
                    border-radius: 4px;
                    padding: 4px 8px;
                    min-height: 28px;
                }}
            """)
        else:
            self.record_button.setStyleSheet(f"""
                QPushButton {{
                    background-color: {self.success_color};
                    color: {self.fg_color};
                    font-weight: bold;
                    border: none;
                    border-radius: 4px;
                    padding: 4px 8px;
                    min-height: 28px;
                }}
            """)

    def darker_color(self, hex_color):
        """Helper to generate a darker shade for hover effects"""
        if not hex_color.startswith('#'):
            hex_color = '#' + hex_color
        rgb = [int(hex_color[i:i+2], 16) for i in (1, 3, 5)]
        darker = [max(0, c - 40) for c in rgb]
        return ''.join([f"{c:02x}" for c in darker])

    def toggle_global_recording(self):
        """Toggle recording for all connected devices simultaneously"""
        self.global_recording = not self.global_recording
        
        if self.global_recording:
            # Start recording for all devices
            for device in self.devices.values():
                device.is_recording = True
                if not device.measurement_thread.isRunning():
                    device.start_measurement(self.interval)
                self.start_live_monitoring(device)
            
            self.record_button.setText("■ Stop Recording")
            self.status_bar.showMessage("Recording started for all connected devices")
        else:
            # Stop recording for all devices
            for device in self.devices.values():
                self.finalize_device_log_file(device)
                device.is_recording = False
            
            self.record_button.setText("● Start Recording")
            self.status_bar.showMessage("Recording stopped for all devices")
        
        self.apply_button_style()

    def safe_execute(func):
        """Decorator to catch and log exceptions in Qt event handlers"""
        def wrapper(*args, **kwargs):
            try:
                return func(*args, **kwargs)
            except Exception as e:
                print(f"Error in {func.__name__}: {str(e)}")
                traceback.print_exc()
        return wrapper

    @safe_execute
    def toggle_test(self, checked):
        if checked:
            self.start_test()
        else:
            self.stop_test()
        self.apply_button_style()

    def change_mode(self, mode_name):
        """Change between different test modes"""
        self.current_mode = mode_name
        self.stop_test()  # Stop any current operation
        
        # Show/hide mode-specific UI elements
        show_charge = mode_name in ["Cycle Test", "Charge Test"]
        show_discharge = mode_name in ["Cycle Test", "Discharge Test"]
        show_rest = mode_name == "Cycle Test"
        
        self.charge_cutoff_label.setVisible(show_charge)
        self.charge_cutoff_input.setVisible(show_charge)
        self.discharge_cutoff_label.setVisible(show_discharge)
        self.discharge_cutoff_input.setVisible(show_discharge)
        self.rest_time_label.setVisible(show_rest)
        self.rest_time_input.setVisible(show_rest)
        
        # Continuous mode checkbox only for cycle test
        self.continuous_mode_check.setVisible(mode_name == "Cycle Test")
        
        # Record button only for live monitoring
        self.record_button.setVisible(mode_name == "Live Monitoring")
        
        # Set button text based on mode and make sure it's visible for test modes
        if mode_name == "Cycle Test":
            self.toggle_button.setText("START CYCLE TEST")
            self.toggle_button.show()
        elif mode_name == "Discharge Test":
            self.toggle_button.setText("START DISCHARGE")
            self.toggle_button.show()
        elif mode_name == "Charge Test":
            self.toggle_button.setText("START CHARGE")
            self.toggle_button.show()
        elif mode_name == "Live Monitoring":
            self.toggle_button.hide()  # Only hide for Live Monitoring
        
        # Reset button state
        self.toggle_button.setChecked(False)
        self.toggle_button.setEnabled(True)
        self.apply_button_style()

        # Reset measurement state and zero the time
        if self.active_device:
            dev = self.active_device
            dev.reset_data()
            
            # Reset the measurement thread's start time
            if hasattr(dev, 'measurement_thread'):
                dev.measurement_thread.start_time = time.time()
            
            # Reset UI displays
            self.capacity_label.setText("0.0000")
            self.energy_label.setText("0.0000")
            self.cycle_label.setText("0")
            self.phase_label.setText("Idle")
            #self.time_label.setText("00:00:00")
            
            # Reset plot
            self.reset_plot()
        
        self.status_bar.showMessage(f"Mode changed to {mode_name}")

        # Update recording button
        if mode_name == "Live Monitoring":
            self.record_button.setVisible(True)
            if self.active_device and self.active_device.is_recording:
                self.record_button.setChecked(True)
                self.record_button.setText("Stop Recording")
            else:
                self.record_button.setChecked(False)
                self.record_button.setText("Start Recording")
        else:
            self.record_button.setVisible(False)

        self.apply_button_style()
        self.status_bar.showMessage(f"Mode changed to {mode_name}")
    
    def reset_test(self):
        if not self.active_device:
            return
            
        dev_manager = self.active_device
        dev_manager.reset_data()  # Reset in DeviceManager
        
        # Reset UI
        self.capacity_label.setText("0.0000")
        self.energy_label.setText("0.0000")
        self.cycle_label.setText("0")
        self.phase_label.setText("Idle")

    def toggle_recording(self):
        """Toggle data recording in Live Monitoring mode"""
        if not self.active_device:
            return
            
        dev = self.active_device
        
        if not dev.is_recording:  # Use device's recording state
            try:
                if self.create_cycle_log_file():
                    dev.is_recording = True  # Set device's recording state
                    self.record_button.setText("Stop Recording")
                    self.apply_button_style()  # Update style
                    self.status_bar.showMessage("Live recording started")
                    # Ensure monitoring is running
                    if not self.test_running:
                        self.start_live_monitoring(self.active_device)
                else:
                    self.record_button.setChecked(False)
                    self.current_cycle_file = None
            except Exception as e:
                print(f"Error starting recording: {e}")
                self.record_button.setChecked(False)
                self.current_cycle_file = None
                QMessageBox.critical(self, "Error", f"Failed to start recording:\n{str(e)}")
        else:
            # Stop recording
            try:
                if hasattr(self, 'current_cycle_file') and self.current_cycle_file:
                    self.finalize_log_file()
                dev.is_recording = False  # Clear device's recording state
                self.record_button.setText("Start Recording")
                self.apply_button_style()  # Update style
                self.status_bar.showMessage("Live recording stopped")
            except Exception as e:
                print(f"Error stopping recording: {e}")

    def handle_continuous_mode_change(self, state):
        """Handle changes to continuous mode checkbox during operation"""
        if not state and self.test_running:  # If unchecked during test
            self.status_bar.showMessage("Continuous mode disabled - will complete current cycle")
            self.continuous_mode_check.setStyleSheet(f"color: {self.warning_color};")
            QTimer.singleShot(2000, lambda: self.continuous_mode_check.setStyleSheet(f"color: {self.fg_color};"))

    def setup_plot(self):
        """Configure the matplotlib plot"""
        self.fig = Figure(figsize=(8, 5), dpi=100, facecolor=self.bg_color)
        self.fig.subplots_adjust(left=0.1, right=0.88, top=0.9, bottom=0.15)
        self.ax = self.fig.add_subplot(111)
        self.ax.set_facecolor('#3B4252')

        # Set initial voltage range
        voltage_padding = 0.2
        min_voltage = max(0, 0.9 - voltage_padding)
        max_voltage = 1.43 + voltage_padding
        self.ax.set_ylim(min_voltage, max_voltage)
        
        # Voltage plot
        self.line_voltage, = self.ax.plot([0], [0], color='#00BFFF', label='Voltage (V)', linewidth=2)
        self.ax.set_ylabel("Voltage (V)", color='#00BFFF')
        self.ax.tick_params(axis='y', labelcolor='#00BFFF')

        # Current plot (right axis)
        self.ax2 = self.ax.twinx()
        current_padding = 0.05
        test_current = 0.1 * 0.2  # Default values
        max_current = test_current * 1.5
        self.ax2.set_ylim(-max_current - current_padding, max_current + current_padding)
        
        self.line_current, = self.ax2.plot([0], [0], 'r-', label='Current (A)', linewidth=2)
        self.ax2.set_ylabel("Current (A)", color='r')
        self.ax2.tick_params(axis='y', labelcolor='r')

        self.ax.set_xlabel('Time (s)', color=self.fg_color)
        self.ax.set_title('Battery Test', color=self.fg_color)
        self.ax.tick_params(axis='x', colors=self.fg_color)
        self.ax.grid(True, color='#4C566A')

        # Position legends
        self.ax.legend(loc='upper left')
        self.ax2.legend(loc='upper right')

        # Embed plot
        self.canvas = FigureCanvas(self.fig)
        self.canvas.setStyleSheet(f"background-color: {self.bg_color};")
        self.main_layout.addWidget(self.canvas, 1)

    def init_device(self):
        """Robust device initialization"""
        try:
            # Close existing session
            if hasattr(self, 'session'):
                try:
                    self.session.end()
                except:
                    pass
                        
            # Create new session
            self.session = Session(ignore_dataflow=True, queue_size=10000)
            self.session.scan()
            
            # Retry mechanism
            retry_count = 0
            while not self.session.devices and retry_count < 3:
                self.handle_device_connection(False, f"Scanning... (Attempt {retry_count+1}/3)")
                QApplication.processEvents()
                time.sleep(1)
                self.session.scan()
                retry_count += 1

            if not self.session.devices:
                self.handle_device_connection(False, "No devices found")
                return
                
            self.devices = {}
            self.active_device = None
            
            for dev in self.session.devices:
                serial = dev.serial if hasattr(dev, 'serial') else str(dev[0])
                logger.info(f"Found device: {serial}")
                manager = DeviceManager(dev=dev, serial=serial)
                self.devices[serial] = manager
                
                # Connect signals for all devices
                manager.measurement_thread.update_signal.connect(self.update_measurements)
                manager.measurement_thread.error_signal.connect(self.handle_device_error)

            # Select first device
            first_serial = next(iter(self.devices.keys()))
            self.active_device = self.devices[first_serial]

            # Update UI
            self.device_combo.clear()
            for serial in self.devices:
                self.device_combo.addItem(serial)
            self.device_combo.setCurrentText(first_serial)

            self.session_active = True
            self.handle_device_connection(True, f"Connected: {first_serial}")
            self.toggle_button.setEnabled(True)     

            # Connect measurement signals
            self.measurement_thread = self.active_device.measurement_thread
            self.measurement_thread.update_signal.connect(self.update_measurements)
            self.measurement_thread.error_signal.connect(self.handle_device_error)

            # Initialize recording state
            self.global_recording = False
            self.record_button.setChecked(False)
            self.record_button.setText("Start Recording")

        except Exception as e:
            self.handle_device_connection(False, f"Initialization failed: {str(e)}")

    def handle_no_devices(self):
        """Handle case when no devices are found"""
        self.session_active = False
        self.active_device = None
        self.status_bar.showMessage("No ADALM1000 devices found")
        self.status_light.setStyleSheet("background-color: red; border-radius: 10px;")
        self.toggle_button.setEnabled(False)
        self.device_combo.clear()
        
        # Show reconnect button
        self.reconnect_btn.setEnabled(True)
        self.reconnect_btn.setVisible(True)

    def handle_device_connection(self, connected, message=None):
        """Update connection status with proper coloring"""
        if connected:
            status = "connected"
            if not message:
                message = "Connected"
        else:
            status = "error" if "fail" in message.lower() else "disconnected"
            if not message:
                message = "Disconnected"
        
        color = self.status_colors.get(status, "orange")
        self.connection_label.setText(message)
        self.status_light.setStyleSheet(f"""
            background-color: {color}; 
            border-radius: 10px;
            min-width: 12px;
            max-width: 12px;
            min-height: 12px;
            max-height: 12px;
        """)
        QApplication.processEvents()

    def check_connection(self):
        """Periodically verify device connection"""
        if not hasattr(self, 'session') or not self.session.devices:
            self.handle_device_error("Device disconnected")
            self.reconnect_device()

    def request_usb_permissions(self):
        """Handle USB permission issues with user interaction"""
        msg = QMessageBox(self)
        msg.setIcon(QMessageBox.Critical)
        msg.setWindowTitle("USB Permission Required")
        msg.setText("Permission needed to access ADALM1000 devices")
        msg.setInformativeText(
            "The application needs elevated privileges to access USB devices.\n\n"
            "Please choose an option:"
        )
        
        # Add buttons
        sudo_button = msg.addButton("Run as Administrator", QMessageBox.ActionRole)
        udev_button = msg.addButton("Fix Permissions", QMessageBox.ActionRole)
        cancel_button = msg.addButton(QMessageBox.Cancel)
        
        msg.exec_()
        
        if msg.clickedButton() == sudo_button:
            # Restart with sudo
            QMessageBox.information(self, "Restarting", 
                                "The application will restart with administrator privileges")
            args = sys.argv[:]
            args.insert(0, sys.executable)
            os.execvp("sudo", ["sudo"] + args)
            
        elif msg.clickedButton() == udev_button:
            # Create udev rule
            rule_content = (
                '# ADALM1000 USB permissions\n'
                'SUBSYSTEM=="usb", ATTR{idVendor}=="064b", ATTR{idProduct}=="784c", MODE="0666"\n'
            )
            
            try:
                # Try to create udev rule
                rule_path = "/etc/udev/rules.d/52-adalm1000.rules"
                with open(rule_path, "w") as f:
                    f.write(rule_content)
                
                # Apply rules
                os.system("sudo udevadm control --reload-rules")
                os.system("sudo udevadm trigger")
                
                QMessageBox.information(self, "Permissions Fixed", 
                                    "USB permissions configured. Please reconnect devices.")
            except Exception as e:
                QMessageBox.critical(self, "Error", 
                                f"Failed to set permissions: {str(e)}\n\n"
                                "Please run these commands manually:\n\n"
                                f"echo '{rule_content}' | sudo tee {rule_path}\n"
                                "sudo udevadm control --reload-rules\n"
                                "sudo udevadm trigger")

    def manual_device_init(self):
        """Manual device initialization workaround"""
        try:
            # Simulate device detection
            self.device_combo.clear()
            self.device_combo.addItem("ADALM1000-1 (Simulated)")
            self.device_combo.addItem("ADALM1000-2 (Simulated)")
            
            # Mock connection
            self.status_light.setStyleSheet("background-color: orange; border-radius: 10px;")
            self.connection_label.setText("Simulated Devices")
            self.session_active = True
            self.toggle_button.setEnabled(True)
            
            QMessageBox.warning(self, "Simulation Mode", 
                            "Using simulated devices - real hardware not detected")
        except Exception as e:
            print(f"Manual init failed: {e}")

    @safe_execute
    def change_device(self, index):
        """Handle switching between connected devices"""
        if not self.session_active or index < 0:
            return
            
        serial = self.device_combo.itemText(index)
        if serial not in self.devices:
            return

        # Store current device state before switching
        old_device = self.active_device
        
        # Disconnect signals from old device's measurement thread
        if old_device and old_device.measurement_thread:
            try:
                with self.plot_mutex:  # Ensure thread-safe disconnection
                    old_device.measurement_thread.update_signal.disconnect(self.update_measurements)
                    old_device.measurement_thread.error_signal.disconnect(self.handle_device_error)
                    if old_device.is_recording:
                        self.finalize_device_log_file(old_device)
            except (TypeError, RuntimeError):
                # Signals weren't connected or already disconnected - safe to ignore
                pass
        
        # Activate new device
        self.active_device = self.devices[serial]
        dev = self.active_device
        
        # Ensure measurement thread exists
        if not hasattr(dev, 'measurement_thread'):
            dev.measurement_thread = MeasurementThread(dev, self.interval, dev)
        
        # Get reference to new thread
        new_thread = dev.measurement_thread
        
        # Connect signals for new device
        with self.plot_mutex:
            new_thread.update_signal.connect(self.update_measurements)
            new_thread.error_signal.connect(self.handle_device_error)
        
        # Start measurement if not running (with thread safety)
        if not new_thread.isRunning():
            new_thread.start()
        
        # Initialize device time tracking if needed
        if not hasattr(dev, 'start_time'):
            dev.start_time = time.time()
        
        # Update UI with current device data
        self.update_ui_from_active_device()
        
        # Handle recording state transition
        if old_device and old_device.is_recording:
            # Finalize old device recording
            self.finalize_device_log_file(old_device)
        
        # Set up recording for new device if global recording is enabled
        if self.global_recording and not dev.is_recording:
            self.start_live_monitoring(dev)
        
        # Update recording button state
        self.record_button.setChecked(dev.is_recording)
        self.record_button.setText("■ Stop Recording" if dev.is_recording else "● Start Recording")
        self.apply_button_style()
        
        # Reset plot for new device
        self.reset_plot()
        
        # Update status
        self.status_bar.showMessage(f"Switched to device: {serial}")
        self.set_connection_status(f"Connected: {serial}", self.status_colors["connected"])

    def update_ui_from_active_device(self):
        dev = self.active_device
        if not dev:
            return

        with self.plot_mutex:
            # Kopiere aktuelle Daten
            x = list(dev.display_time_data)
            y_v = list(dev.display_voltage_data)
            y_c = list(dev.display_current_data)

        # Aktualisiere Plot
        self.line_voltage.set_data(x, y_v)
        self.line_current.set_data(x, y_c)
        self.auto_scale_axes()
        self.canvas.draw_idle()

        # Aktualisiere Labels
        if dev.voltage_data:
            v = dev.voltage_data[-1]
            i = dev.current_data[-1]
            t = dev.time_data[-1] if dev.time_data else 0
            self.voltage_label.setText(f"{v:.4f}")
            self.current_label.setText(f"{abs(i):.4f}")
            self.time_label.setText(self.format_time(t))
            self.capacity_label.setText(f"{dev.capacity_ah:.4f}")
            self.energy_label.setText(f"{dev.energy:.4f}")
            self.cycle_label.setText(str(dev.cycle_count))
            self.phase_label.setText(dev.test_phase)

    @safe_execute
    @pyqtSlot(str, float, float, float)
    def update_measurements(self, serial, voltage, current, current_time):
        """Debugged measurement update handler"""
        try:
            device = self.devices.get(serial)
            if not device:
                logger.error(f"Device {serial} not found")
                return
                
            # Ensure timing is initialized
            if not hasattr(device, 'start_time') or device.start_time is None:
                device.start_time = current_time
                logger.debug(f"Initialized start time for {serial}")
                
            # Calculate elapsed time safely
            try:
                elapsed = current_time - device.start_time
            except TypeError:
                logger.error(f"Invalid timing - current: {current_time}, start: {device.start_time}")
                device.start_time = current_time
                elapsed = 0
                
            # Validate measurements
            if not (0 <= voltage <= 5.0) or not (-0.2 <= current <= 0.2):
                logger.warning(f"Invalid values - V: {voltage:.3f}, I: {current:.3f}")
                return

            # Update data buffers
            device.time_data.append(elapsed)
            device.voltage_data.append(voltage)
            device.current_data.append(current)
            
            # Update display buffers
            device.display_time_data.append(elapsed)
            device.display_voltage_data.append(voltage)
            device.display_current_data.append(current)
            
            # Trim display buffers if needed
            if len(device.display_time_data) > 1000:
                device.display_time_data.popleft()
                device.display_voltage_data.popleft()
                device.display_current_data.popleft()

            # Only update UI for active device
            if device == self.active_device:
                self.voltage_label.setText(f"{voltage:.4f}")
                self.current_label.setText(f"{abs(current):.4f}")
                self.time_label.setText(self.format_time(elapsed))
                
                # Calculate metrics if we have enough data
                if len(device.time_data) > 1:
                    delta_t = device.time_data[-1] - device.time_data[-2]
                    device.capacity_ah += abs(current) * delta_t / 3600
                    device.energy += (voltage * abs(current)) * delta_t / 3600
                    self.capacity_label.setText(f"{device.capacity_ah:.4f}")
                    self.energy_label.setText(f"{device.energy:.4f}")
                
                # Force plot update
                self.update_plot()
                
        except Exception as e:
            logger.error(f"Critical error in update_measurements: {str(e)}")
            traceback.print_exc()

    def adjust_downsampling(self):
        current_length = len(self.time_data)
        if current_length > self.max_points_to_keep * 1.5:
            # Exponentiell erhöhen, aber max. 64
            new_factor = min(64, max(1, self.downsample_factor * 2))
        elif current_length < self.max_points_to_keep // 2:
            # Halbieren, aber min. 1
            new_factor = max(1, self.downsample_factor // 2)
        else:
            return
        
        if new_factor != self.downsample_factor:
            self.downsample_factor = new_factor
            self.status_bar.showMessage(
                f"Downsampling: Factor {self.downsample_factor}", 2000)
    def update_status_and_plot(self):
        """Combined status and plot update"""
        self.update_status()
        self.update_plot()

    def update_status(self):
        """Update status information periodically"""
        now = time.time()
        
        # Update all devices
        for dev_manager in self.devices.values():
            # Only process if device has data
            if not dev_manager.time_data:
                continue
                
            # Update capacity calculation
            if len(dev_manager.time_data) > 1:
                idx = len(dev_manager.time_data) - 1
                delta_t = dev_manager.time_data[idx] - dev_manager.time_data[idx-1]
                current_val = abs(dev_manager.current_data[idx])
                power = dev_manager.voltage_data[idx] * current_val
                dev_manager.capacity_ah += current_val * delta_t / 3600
                dev_manager.energy += power * delta_t / 3600
            
            # Write to log if recording
            if dev_manager.is_recording and dev_manager.log_writer:
                try:
                    if now - getattr(dev_manager, '_last_log_time', 0) >= 1.0:
                        dev_manager.log_writer.writerow([
                            f"{dev_manager.time_data[-1]:.4f}",
                            f"{dev_manager.voltage_data[-1]:.6f}",
                            f"{dev_manager.current_data[-1]:.6f}",
                            "Live",
                            f"{dev_manager.capacity_ah:.4f}",
                            f"{power:.4f}",
                            f"{dev_manager.energy:.4f}"
                        ])
                        dev_manager.log_file.flush()
                        dev_manager._last_log_time = now
                except Exception as e:
                    print(f"Log write error for device {dev_manager.serial}: {e}")
                    dev_manager.is_recording = False
        
        # Update UI for active device
        if self.active_device and self.active_device.time_data:
            dev = self.active_device
            self.capacity_label.setText(f"{dev.capacity_ah:.4f}")
            self.energy_label.setText(f"{dev.energy:.4f}")
        
        # Update elapsed-time display
        if self.active_device and self.active_device.time_data:
            elapsed = self.active_device.time_data[-1]
            self.time_label.setText(self.format_time(elapsed))

    @safe_execute
    def start_test(self):
        """Start the selected test mode using the active device"""
        if not self.active_device:
            QMessageBox.warning(self, "No Device", "No ADALM1000 device selected.")
            self.toggle_button.setChecked(False)
            self.apply_button_style()
            return

        dev_manager = self.active_device
        dev = dev_manager.dev

        # Clean up any previous test
        self.cleanup_test_threads()

        # Reset test state for active device
        self.reset_test()

        # Reset measurement thread timing
        dev_manager.measurement_thread.start_time = time.time()
        dev_manager.measurement_thread.voltage_window.clear()
        dev_manager.measurement_thread.current_window.clear()
        with dev_manager.measurement_thread.measurement_queue.mutex:
            dev_manager.measurement_thread.measurement_queue.queue.clear()
        self.time_label.setText("00:00:00")

        # Reset data buffers
        dev_manager.time_data.clear()
        dev_manager.voltage_data.clear()
        dev_manager.current_data.clear()
        dev_manager.display_time_data.clear()
        dev_manager.display_voltage_data.clear()
        dev_manager.display_current_data.clear()
        dev_manager.aggregation_buffer = {
            'time': [], 'voltage': [], 'current': [], 'count': 0, 'last_plot_time': 0
        }

        # Reset device state
        try:
            dev.channels['A'].mode = pysmu.Mode.HI_Z
            dev.channels['A'].constant(0)
            dev.channels['B'].mode = pysmu.Mode.HI_Z
            dev.channels['B'].constant(0)
        except Exception as e:
            QMessageBox.critical(self, "Device Error", f"Failed to reset device: {e}")
            self.toggle_button.setChecked(False)
            self.apply_button_style()
            return

        # Reset test variables
        dev_manager.capacity_ah = 0.0
        dev_manager.energy = 0.0
        dev_manager.charge_capacity = 0.0
        dev_manager.coulomb_efficiency = 0.0
        dev_manager.cycle_count = 0
        dev_manager.start_time = time.time()
        dev_manager.test_phase = "Running"

        # Set global state
        self.test_running = True
        self.request_stop = False

        # Update UI
        self.phase_label.setText(dev_manager.test_phase)
        self.toggle_button.setText("STOP")
        self.apply_button_style()

        # Get parameters from UI
        try:
            self.capacity = float(self.capacity_input.text())
            self.c_rate = float(self.c_rate_input.text())
            test_current = self.c_rate * self.capacity
            if test_current > 0.2:
                raise ValueError("Current must be ≤ 200mA (0.2A) for ADALM1000")
        except ValueError as e:
            QMessageBox.critical(self, "Input Error", str(e))
            self.stop_test()
            return

        # Create log file - using start_live_monitoring instead of _start_device_recording
        if not self.start_live_monitoring(self.active_device):
            self.stop_test()
            return

        # Start the appropriate test
        if self.current_mode == "Cycle Test":
            try:
                self.charge_cutoff = float(self.charge_cutoff_input.text())
                self.discharge_cutoff = float(self.discharge_cutoff_input.text())
                self.rest_time = float(self.rest_time_input.text())
                if self.charge_cutoff <= self.discharge_cutoff:
                    raise ValueError("Charge cutoff must be higher than discharge cutoff")

                # Start test sequence
                self.test_sequence_thread = QThread()
                self.test_sequence_worker = TestSequenceWorker(
                    self.active_device,
                    test_current,
                    self.charge_cutoff,
                    self.discharge_cutoff,
                    self.rest_time,
                    self.continuous_mode_check.isChecked(),
                    self
                )
                self.test_sequence_worker.moveToThread(self.test_sequence_thread)

                self.test_sequence_worker.update_phase.connect(self.update_test_phase)
                self.test_sequence_worker.update_status.connect(self.status_bar.showMessage)
                self.test_sequence_worker.test_completed.connect(self.finalize_test)
                self.test_sequence_worker.error_occurred.connect(self.handle_test_error)
                self.test_sequence_worker.finished.connect(self.test_sequence_thread.quit)
                self.test_sequence_worker.finished.connect(self.test_sequence_worker.deleteLater)
                self.test_sequence_thread.finished.connect(self.test_sequence_thread.deleteLater)

                self.test_sequence_thread.start()
                QTimer.singleShot(0, self.test_sequence_worker.run)

                self.status_bar.showMessage(f"Cycle test started | Device: {dev.serial} | Current: {test_current:.4f}A")

            except Exception as e:
                QMessageBox.critical(self, "Error", str(e))
                self.stop_test()

        elif self.current_mode == "Discharge Test":
            try:
                self.discharge_cutoff = float(self.discharge_cutoff_input.text())

                self.discharge_thread = QThread()
                self.discharge_worker = DischargeWorker(self.active_device, test_current, self.discharge_cutoff, self)
                self.discharge_worker.moveToThread(self.discharge_thread)

                self.discharge_worker.update_status.connect(self.status_bar.showMessage)
                self.discharge_worker.test_completed.connect(self.finalize_test)
                self.discharge_worker.error_occurred.connect(self.handle_test_error)
                self.discharge_worker.finished.connect(self.discharge_thread.quit)
                self.discharge_worker.finished.connect(self.discharge_worker.deleteLater)
                self.discharge_thread.finished.connect(self.discharge_thread.deleteLater)

                self.discharge_thread.start()
                QTimer.singleShot(0, self.discharge_worker.run)

                self.status_bar.showMessage(f"Discharge test started | Device: {dev.serial} | Current: {test_current:.4f}A")

            except Exception as e:
                QMessageBox.critical(self, "Error", str(e))
                self.stop_test()

        elif self.current_mode == "Charge Test":
            try:
                self.charge_cutoff = float(self.charge_cutoff_input.text())

                self.charge_thread = QThread()
                self.charge_worker = ChargeWorker(self.active_device, test_current, self.charge_cutoff, self)
                self.charge_worker.moveToThread(self.charge_thread)

                self.charge_worker.update_status.connect(self.status_bar.showMessage)
                self.charge_worker.test_completed.connect(self.finalize_test)
                self.charge_worker.error_occurred.connect(self.handle_test_error)
                self.charge_worker.finished.connect(self.charge_thread.quit)
                self.charge_worker.finished.connect(self.charge_worker.deleteLater)
                self.charge_thread.finished.connect(self.charge_thread.deleteLater)

                self.charge_thread.start()
                QTimer.singleShot(0, self.charge_worker.run)

                self.status_bar.showMessage(f"Charge test started | Device: {dev.serial} | Current: {test_current:.4f}A")

            except Exception as e:
                QMessageBox.critical(self, "Error", str(e))
                self.stop_test()

        elif self.current_mode == "Live Monitoring":
            # Ensure we pass the device parameter
            self.start_live_monitoring(self.active_device)

    def start_cycle_test(self):
        """Start the battery cycle test"""
        # Clean up any previous test
        if hasattr(self, 'test_sequence_worker'):
            try:
                self.test_sequence_worker.stop()
            except:
                pass
            self.test_sequence_worker.deleteLater()
        if hasattr(self, 'test_sequence_thread'):
            self.test_sequence_thread.quit()
            self.test_sequence_thread.wait()
            self.test_sequence_thread.deleteLater()
            del self.test_sequence_thread
        self.reset_test()
        self.reset_plot()
        if hasattr(self, 'measurement_thread'):
            self.measurement_thread.start_time = time.time()
            
        # Reset stop flag
        self.request_stop = False

        if not self.test_running:
            try:
                # Get parameters from UI
                self.capacity = float(self.capacity_input.text())
                self.charge_cutoff = float(self.charge_cutoff_input.text())
                self.discharge_cutoff = float(self.discharge_cutoff_input.text())
                self.rest_time = float(self.rest_time_input.text())
                self.c_rate = float(self.c_rate_input.text())
                
                # Validate inputs
                if self.capacity <= 0:
                    raise ValueError("Battery capacity must be positive")
                if self.charge_cutoff <= self.discharge_cutoff:
                    raise ValueError("Charge cutoff must be higher than discharge cutoff")
                if self.c_rate <= 0:
                    raise ValueError("C-rate must be positive")
                
                test_current = self.c_rate * self.capacity
                if test_current > 0.2:
                    raise ValueError("Current must be ≤200mA (0.2A) for ADALM1000")
                
                # Clear ALL previous data completely
                with self.plot_mutex:
                    self.time_data.clear()
                    self.voltage_data.clear()
                    self.current_data.clear()
                    self.phase_data.clear()
                
                # Reset capacities and timing
                self.start_time = time.time()
                self.last_update_time = self.start_time
                self.capacity_ah = 0.0
                self.charge_capacity = 0.0
                self.coulomb_efficiency = 0.0
                self.cycle_count = 0
                self.energy = 0.0

                # Reset measurement thread's timer and queues
                if hasattr(self, 'measurement_thread'):
                    self.measurement_thread.start_time = time.time()
                    self.measurement_thread.voltage_window.clear()
                    self.measurement_thread.current_window.clear()
                    with self.measurement_thread.measurement_queue.mutex:
                        self.measurement_thread.measurement_queue.queue.clear()
                
                # Reset plot completely
                self.reset_plot()

                # Start test
                self.test_running = True
                self.start_time = time.time()
                self.last_update_time = time.time()
                self.test_phase = "Initial Discharge"
                self.phase_label.setText(self.test_phase)
                
                self.toggle_button.setChecked(True)
                self.toggle_button.setText("STOP")
                self.apply_button_style()
                self.status_bar.showMessage(f"Cycle test started | Current: {test_current:.4f}A")
                
                # Create log file
                self.create_cycle_log_file()
                
                # Start test sequence in a QThread
                self.test_sequence_thread = QThread()
                self.test_sequence_worker = TestSequenceWorker(
                    self.active_device.dev,
                    test_current,
                    self.charge_cutoff,
                    self.discharge_cutoff,
                    self.rest_time,
                    self.continuous_mode_check.isChecked(),
                    self  # Pass reference to main window for callbacks
                )
                self.test_sequence_worker.moveToThread(self.test_sequence_thread)
                
                # Connect signals
                self.test_sequence_worker.update_phase.connect(self.update_test_phase)
                self.test_sequence_worker.update_status.connect(self.status_bar.showMessage)
                self.test_sequence_worker.test_completed.connect(self.finalize_test)
                self.test_sequence_worker.error_occurred.connect(self.handle_test_error)
                self.test_sequence_worker.finished.connect(self.test_sequence_thread.quit)
                self.test_sequence_worker.finished.connect(self.test_sequence_worker.deleteLater)
                self.test_sequence_thread.finished.connect(self.test_sequence_thread.deleteLater)
                
                # Start the thread and the worker's run method
                self.test_sequence_thread.start()
                QTimer.singleShot(0, self.test_sequence_worker.run)
                
            except Exception as e:
                QMessageBox.critical(self, "Error", str(e))
                # Ensure buttons are in correct state if error occurs
                self.toggle_button.setChecked(False)
                self.toggle_button.setText("START")
                self.apply_button_style()
                self.toggle_button.setEnabled(True)

    def start_discharge_test(self):
        """Start the battery discharge test"""
        # Clean up any previous test
        self.reset_test()        # löscht time_data, voltage_data, current_data, display_*, phase_data
        self.reset_plot() 
        if hasattr(self, 'measurement_thread'):
            self.measurement_thread.start_time = time.time()
        if hasattr(self, 'discharge_worker'):
            try:
                self.discharge_worker.stop()
            except:
                pass
            self.discharge_worker.deleteLater()
        if hasattr(self, 'discharge_thread'):
            self.discharge_thread.quit()
            self.discharge_thread.wait()  # warte unbegrenzt, bis er wirklich fertig ist
            self.discharge_thread.deleteLater()
            del self.discharge_thread
        
        # Reset stop flag
        self.request_stop = False

        if not self.test_running:
            try:
                # Get parameters from UI
                self.capacity = float(self.capacity_input.text())
                self.discharge_cutoff = float(self.discharge_cutoff_input.text())
                self.c_rate = float(self.c_rate_input.text())
                
                # Validate inputs
                if self.capacity <= 0:
                    raise ValueError("Battery capacity must be positive")
                if self.c_rate <= 0:
                    raise ValueError("C-rate must be positive")
                
                test_current = self.c_rate * self.capacity
                if test_current > 0.2:
                    raise ValueError("Current must be ≤200mA (0.2A) for ADALM1000")
                
                # Clear ALL previous data completely
                with self.plot_mutex:
                    self.time_data.clear()
                    self.voltage_data.clear()
                    self.current_data.clear()
                
                # Reset capacities and timing
                self.start_time = time.time()
                self.last_update_time = self.start_time
                self.capacity_ah = 0.0
                self.energy = 0.0
                self.cycle_count = 1

                # Reset measurement thread's timer and queues
                if hasattr(self, 'measurement_thread'):
                    self.measurement_thread.start_time = time.time()
                    self.measurement_thread.voltage_window.clear()
                    self.measurement_thread.current_window.clear()
                    with self.measurement_thread.measurement_queue.mutex:
                        self.measurement_thread.measurement_queue.queue.clear()
                
                # Reset plot completely
                self.reset_plot()

                # Start test
                self.test_running = True
                self.start_time = time.time()
                self.last_update_time = time.time()
                self.test_phase = "Discharge"
                self.phase_label.setText(self.test_phase)
                
                self.toggle_button.setChecked(True)
                self.toggle_button.setText("STOP")
                self.apply_button_style()
                self.status_bar.showMessage(f"Discharge started | Current: {test_current:.4f}A")
                
                # Create log file
                self.create_cycle_log_file()
                
                # Start discharge worker in a QThread
                self.discharge_thread = QThread()
                self.discharge_worker = DischargeWorker(
                    self.active_device.dev,
                    test_current,
                    self.discharge_cutoff,
                    self  # Pass reference to main window for callbacks
                )
                self.discharge_worker.moveToThread(self.discharge_thread)
                
                # Connect signals
                self.discharge_worker.update_status.connect(self.status_bar.showMessage)
                self.discharge_worker.test_completed.connect(self.finalize_test)
                self.discharge_worker.error_occurred.connect(self.handle_test_error)
                self.discharge_worker.finished.connect(self.discharge_thread.quit)
                self.discharge_worker.finished.connect(self.discharge_worker.deleteLater)
                self.discharge_thread.finished.connect(self.discharge_thread.deleteLater)
                
                # Start the thread and the worker's run method
                self.discharge_thread.start()
                QTimer.singleShot(0, self.discharge_worker.run)
                
            except Exception as e:
                QMessageBox.critical(self, "Error", str(e))
                # Ensure buttons are in correct state if error occurs
                self.toggle_button.setChecked(False)
                self.toggle_button.setText("START")
                self.apply_button_style()
                self.toggle_button.setEnabled(True)

    def start_charge_test(self):
        """Start the battery charge test"""
        # Clean up any previous test
        if hasattr(self, 'charge_worker'):
            try:
                self.charge_worker.stop()
            except:
                pass
            self.charge_worker.deleteLater()
        if hasattr(self, 'charge_thread'):
            self.charge_thread.quit()
            self.charge_thread.wait()
            self.charge_thread.deleteLater()
            del self.charge_thread
        self.reset_test()
        self.reset_plot()
        if hasattr(self, 'measurement_thread'):
            self.measurement_thread.start_time = time.time()
        
        # Reset stop flag
        self.request_stop = False

        if not self.test_running:
            try:
                # Get parameters from UI
                self.capacity = float(self.capacity_input.text())
                self.charge_cutoff = float(self.charge_cutoff_input.text())
                self.c_rate = float(self.c_rate_input.text())
                
                # Validate inputs
                if self.capacity <= 0:
                    raise ValueError("Battery capacity must be positive")
                if self.c_rate <= 0:
                    raise ValueError("C-rate must be positive")
                
                test_current = self.c_rate * self.capacity
                if test_current > 0.2:
                    raise ValueError("Current must be ≤200mA (0.2A) for ADALM1000")
                
                # Clear ALL previous data completely
                with self.plot_mutex:
                    self.time_data.clear()
                    self.voltage_data.clear()
                    self.current_data.clear()
                
                # Reset capacities and timing
                self.start_time = time.time()
                self.last_update_time = self.start_time
                self.capacity_ah = 0.0
                self.energy = 0.0
                self.cycle_count = 1

                # Reset measurement thread
                if hasattr(self, 'measurement_thread'):
                    self.measurement_thread.start_time = time.time()
                    self.measurement_thread.voltage_window.clear()
                    self.measurement_thread.current_window.clear()
                    with self.measurement_thread.measurement_queue.mutex:
                        self.measurement_thread.measurement_queue.queue.clear()
                
                # Reset plot
                self.reset_plot()

                # Start test
                self.test_running = True
                self.start_time = time.time()
                self.last_update_time = time.time()
                self.test_phase = "Charge"
                self.phase_label.setText(self.test_phase)
                
                self.toggle_button.setChecked(True)
                self.toggle_button.setText("STOP")
                self.apply_button_style()
                self.status_bar.showMessage(f"Charge started @ {test_current:.3f}A to {self.charge_cutoff}V")
                
                # Create log file
                self.create_cycle_log_file()
                
                # Start charge worker in a QThread
                self.charge_thread = QThread()
                self.charge_worker = ChargeWorker(
                    self.active_device.dev,
                    test_current,
                    self.charge_cutoff,
                    self
                )
                self.charge_worker.moveToThread(self.charge_thread)
                
                # Connect signals
                self.charge_worker.update_status.connect(self.status_bar.showMessage)
                self.charge_worker.test_completed.connect(self.finalize_test)
                self.charge_worker.error_occurred.connect(self.handle_test_error)
                self.charge_worker.finished.connect(self.charge_thread.quit)
                self.charge_worker.finished.connect(self.charge_worker.deleteLater)
                self.charge_thread.finished.connect(self.charge_thread.deleteLater)
                
                # Start the thread
                self.charge_thread.start()
                QTimer.singleShot(0, self.charge_worker.run)
                
            except Exception as e:
                QMessageBox.critical(self, "Error", str(e))
                self.toggle_button.setChecked(False)
                self.toggle_button.setText("START")
                self.apply_button_style()
                self.toggle_button.setEnabled(True)
            
    def start_live_monitoring(self, device):
        """Initialize logging for a specific device (replaces create_device_log_file)"""
        try:
            if device.is_recording:
                return True  # Already recording
                
            # Ensure log directory exists
            os.makedirs(device.log_dir, exist_ok=True)
            if not os.access(device.log_dir, os.W_OK):
                QMessageBox.critical(self, "Error", 
                                f"No write permissions in {device.log_dir}")
                return False

            # Generate filename with device serial and timestamp
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
            clean_serial = device.serial.replace(":", "_")[-8:]  # Clean for filename
            filename = os.path.join(
                device.log_dir,
                f"battery_test_{clean_serial}_{timestamp}.csv"
            )

            # Open file and initialize writer
            device.log_file = open(filename, 'w', newline='')
            device.log_writer = csv.writer(device.log_file)
            
            # Write comprehensive header
            device.log_file.write(f"# ADALM1000 Battery Test Log\n")
            device.log_file.write(f"# Device Serial: {device.serial}\n")
            device.log_file.write(f"# Start Time: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}\n")
            device.log_file.write(f"# Test Mode: {self.current_mode}\n")
            
            if hasattr(self, 'capacity_input'):
                device.log_file.write(f"# Battery Capacity: {self.capacity_input.text()} Ah\n")
            
            # Mode-specific parameters
            if self.current_mode == "Cycle Test":
                device.log_file.write(f"# Charge Cutoff: {self.charge_cutoff_input.text()} V\n")
                device.log_file.write(f"# Discharge Cutoff: {self.discharge_cutoff_input.text()} V\n")
                device.log_file.write(f"# Rest Time: {self.rest_time_input.text()} h\n")
            
            device.log_file.write("#\n")  # End of header
            
            # Write column headers
            if self.current_mode == "Cycle Test":
                device.log_writer.writerow([
                    "Time(s)", "Voltage(V)", "Current(A)", "Phase",
                    "Discharge_Capacity(Ah)", "Charge_Capacity(Ah)",
                    "Coulomb_Eff(%)", "Cycle"
                ])
            else:
                device.log_writer.writerow([
                    "Time(s)", "Voltage(V)", "Current(A)", "Phase",
                    "Capacity(Ah)", "Power(W)", "Energy(Wh)"
                ])
            
            device.is_recording = True
            device._last_log_time = 0
            return True
            
        except Exception as e:
            error_msg = f"Failed to start recording for {device.serial}:\n{str(e)}"
            print(error_msg)
            QMessageBox.critical(self, "Recording Error", error_msg)
            if device.log_file:
                try:
                    device.log_file.close()
                except:
                    pass
            device.log_file = None
            device.log_writer = None
            return False

    def finalize_device_log_file(self, device):
        """Properly finalize and close a device's log file"""
        if not device.is_recording or not device.log_file:
            return
            
        try:
            # Write test summary footer
            device.log_file.write("\n# TEST SUMMARY\n")
            device.log_file.write(f"# End Time: {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}\n")
            
            if device.time_data:
                duration = device.time_data[-1] if device.time_data else 0
                device.log_file.write(f"# Duration: {self.format_time(duration)}\n")
                device.log_file.write(f"# Final Voltage: {device.voltage_data[-1]:.4f} V\n")
                device.log_file.write(f"# Final Current: {device.current_data[-1]:.4f} A\n")
            
            device.log_file.write(f"# Total Capacity: {device.capacity_ah:.6f} Ah\n")
            device.log_file.write(f"# Total Energy: {device.energy:.6f} Wh\n")
            
            if self.current_mode == "Cycle Test":
                device.log_file.write(f"# Cycles Completed: {device.cycle_count}\n")
                if device.charge_capacity > 0:
                    device.log_file.write(f"# Coulomb Efficiency: {device.coulomb_efficiency:.2f}%\n")
            
        except Exception as e:
            print(f"Error writing footer for {device.serial}: {str(e)}")
        finally:
            try:
                device.log_file.close()
            except:
                pass
            device.log_file = None
            device.log_writer = None
            device.is_recording = False

    def format_time(self, seconds):
        """Convert seconds to hh:mm:ss format"""
        hours = int(seconds // 3600)
        minutes = int((seconds % 3600) // 60)
        seconds = int(seconds % 60)
        return f"{hours:02d}:{minutes:02d}:{seconds:02d}"

    @safe_execute
    def stop_test(self):
        """Request immediate stop with proper visual feedback"""
        # Immediate red button feedback
        self.toggle_button.setStyleSheet(f"""
            QPushButton {{
                background-color: {self.status_colors["warning"]};
                color: white;
                font-weight: bold;
            }}
        """)
        QApplication.processEvents()

        if not self.test_running:
            self.reset_button_state()
            return

        try:
            # Stop operations
            self.request_stop = True
            self.test_running = False
            self.measuring = False

            # Stop workers
            workers = ['test_sequence_worker', 'discharge_worker', 'charge_worker']
            for worker in workers:
                if hasattr(self, worker):
                    getattr(self, worker).stop()

            # Reset device
            if self.active_device:
                self.active_device.dev.channels['A'].mode = pysmu.Mode.HI_Z
                self.active_device.dev.channels['A'].constant(0)
                self.handle_device_connection(True)  # Confirm connection

        except Exception as e:
            self.handle_device_connection(False, e)
        finally:
            # Clean up
            self.reset_test_data()
            self.reset_plot()
            self.reset_button_state()
            
            if hasattr(self, 'current_cycle_file'):
                self.finalize_log_file()

            self.status_bar.showMessage("Test stopped")

    def set_connection_status(self, text, color=None):
        """Update connection status with optional color"""
        if color is None:
            if "error" in text.lower():
                color = self.status_colors["error"]
            elif "disconnect" in text.lower():
                color = self.status_colors["disconnected"]
            else:
                color = self.status_colors["connected"]
        
        self.connection_label.setText(text)
        self.status_light.setStyleSheet(f"""
            background-color: {color};
            border-radius: 10px;
            min-width: 12px;
            max-width: 12px;
            min-height: 12px;
            max-height: 12px;
        """)
        QApplication.processEvents()

    def reset_button_state(self):
        """Reset button to appropriate default state"""
        mode = getattr(self, 'current_mode', 'Live Monitoring')
        text = {
            'Cycle Test': "START CYCLE TEST",
            'Discharge Test': "START DISCHARGE",
            'Charge Test': "START CHARGE"
        }.get(mode, "START")
        
        self.toggle_button.setChecked(False)
        self.toggle_button.setText(text)
        self.apply_button_style()
        self.toggle_button.setStyleSheet(f"""
            QPushButton {{
                background-color: {self.success_color};
                color: {self.fg_color};
                font-weight: bold;
            }}
            QPushButton:checked {{
                background-color: {self.warning_color};
            }}
            QPushButton:disabled {{
                background-color: #4C566A;
            }}
        """)

    def reset_button_style(self):
        """Reset button to default style"""
        mode = getattr(self, 'current_mode', 'Live Monitoring')
        text = {
            'Cycle Test': "START CYCLE TEST",
            'Discharge Test': "START DISCHARGE", 
            'Charge Test': "START CHARGE",
        }.get(mode, "START")
        
        self.toggle_button.setText(text)
        self.toggle_button.setStyleSheet(f"""
            QPushButton {{
                background-color: {self.success_color};
                color: {self.fg_color};
                font-weight: bold;
            }}
            QPushButton:checked {{
                background-color: {self.warning_color};
            }}
        """)

    def closeEvent(self, event):
        """Ensure clean shutdown"""
        self.stop_test()
        
        # Stop all timers
        self.status_timer.stop()
        
        # Close all log files
        for device in self.devices.values():
            if device.is_recording:
                self.finalize_device_log_file(device)
        
        # Clean up threads
        if hasattr(self, 'measurement_thread') and self.measurement_thread:
            self.measurement_thread.stop()
            self.measurement_thread.wait(1000)
        
        event.accept()

    def reset_test_data(self):
        if not self.active_device:
            return
            
        dev = self.active_device
        # Clear all data buffers
        dev.time_data.clear()
        dev.voltage_data.clear()
        dev.current_data.clear()
        
        # Display-Daten ebenfalls zurücksetzen
        dev.display_time_data.clear()
        dev.display_voltage_data.clear()
        dev.display_current_data.clear()
        
        # Reset statistics
        dev.capacity_ah = 0.0
        dev.energy = 0.0
        dev.charge_capacity = 0.0
        dev.coulomb_efficiency = 0.0
        dev.test_phase = "Idle"
        
        # Reset UI displays
        self.voltage_label.setText("0.000")
        self.current_label.setText("0.000")
        #self.time_label.setText("00:00:00")
        self.capacity_label.setText("0.0000")
        self.energy_label.setText("0.0000")
        self.phase_label.setText("Idle")

    def finalize_test(self):
        """Final cleanup after test completes or is stopped"""
        try:
            # 1. Stop any active measurement or test operations
            self.measuring = False
            self.test_running = False
            
            # 2. Reset device to safe state
            try:
                self.active_device.dev.channels['A'].mode = pysmu.Mode.HI_Z
                self.active_device.dev.channels['A'].constant(0)
                self.active_device.dev.channels['B'].mode = pysmu.Mode.HI_Z
                self.active_device.dev.channels['B'].constant(0)
            except Exception as e:
                print(f"Error resetting device in finalize: {e}")

            # 3. Clean up test sequence thread safely
            if hasattr(self, 'test_sequence_thread'):
                try:
                    if self.test_sequence_thread.isRunning():
                        if hasattr(self, 'test_sequence_worker'):
                            try:
                                self.test_sequence_worker.stop()
                            except RuntimeError:
                                pass
                        
                        self.test_sequence_thread.quit()
                        self.test_sequence_thread.wait(500)
                except Exception as e:
                    print(f"Error stopping test sequence thread: {e}")
                finally:
                    if hasattr(self, 'test_sequence_worker'):
                        try:
                            if not sip.isdeleted(self.test_sequence_worker):
                                self.test_sequence_worker.deleteLater()
                        except:
                            pass
                    
                    if hasattr(self, 'test_sequence_thread'):
                        try:
                            if not sip.isdeleted(self.test_sequence_thread):
                                self.test_sequence_thread.deleteLater()
                        except:
                            pass
                        finally:
                            if hasattr(self, 'test_sequence_thread'):
                                del self.test_sequence_thread

            # 4. Clean up discharge thread safely
            if hasattr(self, 'discharge_thread'):
                try:
                    if self.discharge_thread.isRunning():
                        if hasattr(self, 'discharge_worker'):
                            try:
                                self.discharge_worker.stop()
                            except RuntimeError:
                                pass
                        
                        self.discharge_thread.quit()
                        self.discharge_thread.wait(500)
                except Exception as e:
                    print(f"Error stopping discharge thread: {e}")
                finally:
                    if hasattr(self, 'discharge_worker'):
                        try:
                            if not sip.isdeleted(self.discharge_worker):
                                self.discharge_worker.deleteLater()
                        except:
                            pass
                    
                    if hasattr(self, 'discharge_thread'):
                        try:
                            if not sip.isdeleted(self.discharge_thread):
                                self.discharge_thread.deleteLater()
                        except:
                            pass
                        finally:
                            if hasattr(self, 'discharge_thread'):
                                del self.discharge_thread

            # 5. Clean up charge thread safely (using same pattern as discharge thread)
            if hasattr(self, 'charge_thread'):
                try:
                    if self.charge_thread.isRunning():
                        if hasattr(self, 'charge_worker'):
                            try:
                                self.charge_worker.stop()
                            except RuntimeError:
                                pass
                        
                        self.charge_thread.quit()
                        self.charge_thread.wait(500)
                except Exception as e:
                    print(f"Error stopping charge thread: {e}")
                finally:
                    if hasattr(self, 'charge_worker'):
                        try:
                            if not sip.isdeleted(self.charge_worker):
                                self.charge_worker.deleteLater()
                        except:
                            pass
                    
                    if hasattr(self, 'charge_thread'):
                        try:
                            if not sip.isdeleted(self.charge_thread):
                                self.charge_thread.deleteLater()
                        except:
                            pass
                        finally:
                            if hasattr(self, 'charge_thread'):
                                del self.charge_thread

            # 6. Finalize log file
            self.finalize_log_file()

            # 7. Reset UI and state
            self.request_stop = False
            self.toggle_button.setChecked(False)
            self.toggle_button.setText("START")
            self.apply_button_style()
            self.toggle_button.setEnabled(True)
            self.apply_button_style()  # Add this line
            self.test_running = False
            
            # 8. Show completion message if test wasn't stopped by user
            if not self.request_stop:
                test_current = self.c_rate * self.capacity
                test_conditions = self.test_conditions_input.text() if hasattr(self, 'test_conditions_input') else "N/A"
                
                if self.current_mode == "Cycle Test":
                    message = (
                        f"Cycle test completed | "
                        f"Cycle {self.cycle_count} | "
                        f"Capacity: {self.capacity_ah:.4f}Ah | "
                        f"Efficiency: {self.coulomb_efficiency:.1f}%"
                    )
                    
                    QMessageBox.information(
                        self,
                        "Test Completed",
                        f"Cycle test completed successfully.\n\n"
                        f"Test Parameters:\n"
                        f"- Capacity: {self.capacity} Ah\n"
                        f"- Current: {test_current:.4f} A (C/{1/self.c_rate:.1f})\n"
                        f"- Charge Cutoff: {self.charge_cutoff} V\n"
                        f"- Discharge Cutoff: {self.discharge_cutoff} V\n"
                        f"- Conditions: {test_conditions}\n\n"
                        f"Results:\n"
                        f"- Cycles: {self.cycle_count}\n"
                        f"- Discharge capacity: {self.capacity_ah:.4f}Ah\n"
                        f"- Coulombic efficiency: {self.coulomb_efficiency:.1f}%"
                    )
                elif self.current_mode == "Discharge Test":
                    message = (
                        f"Discharge completed | "
                        f"Capacity: {self.capacity_ah:.4f}Ah | "
                        f"Energy: {self.energy:.4f}Wh"
                    )
                    
                    QMessageBox.information(
                        self,
                        "Discharge Completed",
                        f"Discharge test completed successfully.\n\n"
                        f"Test Parameters:\n"
                        f"- Capacity: {self.capacity} Ah\n"
                        f"- Current: {test_current:.4f} A (C/{1/self.c_rate:.1f})\n"
                        f"- Discharge Cutoff: {self.discharge_cutoff} V\n"
                        f"- Conditions: {test_conditions}\n\n"
                        f"Results:\n"
                        f"- Discharge capacity: {self.capacity_ah:.4f}Ah\n"
                        f"- Energy delivered: {self.energy:.4f}Wh"
                    )
                
                self.status_bar.showMessage(message)

        except Exception as e:
            print(f"Error in finalize_test: {e}")
            import traceback
            traceback.print_exc()
            # Ensure we don't leave the UI in a locked state
            self.toggle_button.setChecked(False)
            self.toggle_button.setText("START")
            self.apply_button_style()
            self.toggle_button.setEnabled(True)
            self.status_bar.showMessage("Error during test finalization")

    def reset_plot(self):
        """Completely reset the plot to initial state"""
        # Clear plot data
        self.line_voltage.set_data([], [])
        self.line_current.set_data([], [])
        
        # Reset axes
        self.ax.set_xlim(0, 10)
        self.ax.set_ylim(0, 5.0)  # Full voltage range
        self.ax2.set_ylim(-0.25, 0.25)  # Full current range
        
        # Redraw with slight delay to ensure UI updates
        QTimer.singleShot(50, self.canvas.draw_idle)

    def update_status_and_plot(self):
        """Combined status and plot update"""
        self.update_status()
        self.update_plot()

    def update_plot(self):
        """Debugged plot update"""
        if not self.active_device:
            logger.warning("No active device in update_plot")
            return
            
        try:
            dev = self.active_device
            with self.plot_mutex:
                if not dev.display_time_data:
                    logger.warning(f"No data to plot for {dev.serial}")
                    return
                    
                x_data = list(dev.display_time_data)
                y1_data = list(dev.display_voltage_data)
                y2_data = list(dev.display_current_data)
            
            self.line_voltage.set_data(x_data, y1_data)
            self.line_current.set_data(x_data, y2_data)
            
            # Auto-scale only when significant changes occur
            if len(x_data) > 1 and x_data[-1] - x_data[0] > 1.0:
                self.auto_scale_axes()
            
            self.canvas.draw_idle()
            logger.debug(f"Plot updated for {dev.serial} with {len(x_data)} points")
            
        except Exception as e:
            logger.error(f"Plot update failed: {str(e)}")

    def auto_scale_axes(self):
        """Auto-scale plot axes with appropriate padding and strict boundaries"""
        if not self.active_device or not self.active_device.time_data:
            return
        
        dev = self.active_device
        min_time = 0
        max_time = dev.time_data[-1]
        current_xlim = self.ax.get_xlim()
        
        if max_time > current_xlim[1] * 0.95:
            new_max = max_time * 1.05
            self.ax.set_xlim(min_time, new_max)
            self.ax2.set_xlim(min_time, new_max)
        
        voltage_padding = 0.2
        if dev.voltage_data:
            min_voltage = max(0, min(dev.voltage_data) - voltage_padding)
            max_voltage = min(5.0, max(dev.voltage_data) + voltage_padding)
            current_ylim = self.ax.get_ylim()
            if (abs(current_ylim[0] - min_voltage) > 0.1 or abs(current_ylim[1] - max_voltage) > 0.1):
                self.ax.set_ylim(min_voltage, max_voltage)
        
        current_padding = 0.05
        if dev.current_data:
            min_current = max(-0.25, min(dev.current_data) - current_padding)
            max_current = min(0.25, max(dev.current_data) + current_padding)
            current_ylim2 = self.ax2.get_ylim()
            if (abs(current_ylim2[0] - min_current) > 0.02 or abs(current_ylim2[1] - max_current) > 0.02):
                self.ax2.set_ylim(min_current, max_current)

    @pyqtSlot(str)
    def handle_device_error(self, error_msg):
        """Handle device errors with proper connection status"""
        logger.error(f"Device error: {error_msg}")
        self.set_connection_status(f"Error: {error_msg}", "orange")
        self.reconnect_btn.setVisible(True)
        self.reconnect_btn.setEnabled(True)
        self.toggle_button.setEnabled(False)
        
        # Attempt automatic recovery
        QTimer.singleShot(2000, self.reconnect_device)
    
    def validate_measurements(self, voltage, current):
        """Filter out invalid measurements"""
        # Fix negative values caused by connection issues
        if voltage < 0 or not (0 <= voltage <= 5.0):
            return False
        if abs(current) > 0.3:  # Beyond ADALM1000's ±200mA range
            return False
        return True
        
    @pyqtSlot(str)
    def update_test_phase(self, phase_text):
        """Update the test phase display"""
        self.test_phase = phase_text
        self.phase_label.setText(phase_text)
    
    @pyqtSlot(str)
    def handle_test_error(self, error_msg):
        """Handle errors from the test sequence with complete cleanup"""
        try:
            # 1. Notify user
            QMessageBox.critical(self, "Test Error", 
                            f"An error occurred:\n{error_msg}\n\nAttempting to recover...")
            
            # 2. Stop all operations
            self.stop_test()
            
            # 3. Reset UI elements
            if hasattr(self, 'line_voltage'):
                try:
                    self.line_voltage.set_data([], [])
                    self.line_current.set_data([], [])
                    self.ax.set_xlim(0, 1)
                    self.ax2.set_xlim(0, 1)
                    self.canvas.draw()
                except Exception as plot_error:
                    print(f"Plot reset error: {plot_error}")
            
            # 4. Update status
            self.status_bar.showMessage(f"Error: {error_msg} - Reconnecting...")
            self.status_light.setStyleSheet("background-color: orange; border-radius: 10px;")
            
            # 5. Attempt recovery
            QTimer.singleShot(1000, self.attempt_reconnect)  # Delay before reconnect
            
        except Exception as e:
            print(f"Error in error handler: {e}")
            # Fallback - restart application?
            QMessageBox.critical(self, "Fatal Error", 
                            "The application needs to restart due to an unrecoverable error")
            QTimer.singleShot(1000, self.close)

    def attempt_reconnect(self):
        """Attempt to reconnect automatically"""
        QMessageBox.critical(
            self,
            "Device Connection Error",
            "Could not connect to ADALM1000\n\n"
            "1. Check USB cable connection\n"
            "2. The device will attempt to reconnect automatically"
        )
        
        QTimer.singleShot(1000, self.reconnect_device)

    def cleanup_test_threads(self):
        """Clean up any existing test threads before starting a new test"""
        # Stop and clean up test sequence thread if it exists
        if hasattr(self, 'test_sequence_thread'):
            try:
                if hasattr(self, 'test_sequence_worker'):
                    self.test_sequence_worker.stop()
                self.test_sequence_thread.quit()
                self.test_sequence_thread.wait(500)
            except Exception as e:
                print(f"Error cleaning up test sequence thread: {e}")
            finally:
                if hasattr(self, 'test_sequence_worker'):
                    try:
                        self.test_sequence_worker.deleteLater()
                    except:
                        pass
                if hasattr(self, 'test_sequence_thread'):
                    try:
                        self.test_sequence_thread.deleteLater()
                    except:
                        pass

        # Stop and clean up discharge thread if it exists
        if hasattr(self, 'discharge_thread'):
            try:
                if hasattr(self, 'discharge_worker'):
                    self.discharge_worker.stop()
                self.discharge_thread.quit()
                self.discharge_thread.wait(500)
            except Exception as e:
                print(f"Error cleaning up discharge thread: {e}")
            finally:
                if hasattr(self, 'discharge_worker'):
                    try:
                        self.discharge_worker.deleteLater()
                    except:
                        pass
                if hasattr(self, 'discharge_thread'):
                    try:
                        self.discharge_thread.deleteLater()
                    except:
                        pass

        # Stop and clean up charge thread if it exists
        if hasattr(self, 'charge_thread'):
            try:
                if hasattr(self, 'charge_worker'):
                    self.charge_worker.stop()
                self.charge_thread.quit()
                self.charge_thread.wait(500)
            except Exception as e:
                print(f"Error cleaning up charge thread: {e}")
            finally:
                if hasattr(self, 'charge_worker'):
                    try:
                        self.charge_worker.deleteLater()
                    except:
                        pass
                if hasattr(self, 'charge_thread'):
                    try:
                        self.charge_thread.deleteLater()
                    except:
                        pass

    def reconnect_device(self):
        """Comprehensive device reconnection handler"""
        try:
            self.handle_device_connection(False, "Reconnecting...")
            
            # 1. Clean up existing connections
            if hasattr(self, 'measurement_thread') and self.measurement_thread:
                try:
                    self.measurement_thread.stop()
                    if not self.measurement_thread.wait(500):
                        self.measurement_thread.terminate()
                except Exception as e:
                    print(f"Error stopping measurement thread: {e}")

            if hasattr(self, 'session') and self.session:
                try:
                    self.session.end()
                except Exception as e:
                    print(f"Error ending session: {e}")

            # 2. Initialize new session
            self.session = pysmu.Session(ignore_dataflow=True, queue_size=10000)
            self.session.scan()
            
            if not self.session.devices:
                self.handle_device_connection(False, "No devices detected")
                return
                
            self.session.start(0)
            
            # 3. Re-establish device connection
            if hasattr(self, 'active_device') and self.active_device:
                # Try to find the same device by serial
                target_serial = self.active_device.serial
                for dev in self.session.devices:
                    if dev.serial == target_serial:
                        # Recreate the DeviceManager
                        self.active_device = DeviceManager(dev)
                        self.devices[target_serial] = self.active_device
                        break
            else:
                # No previous device, just use first available
                dev = self.session.devices[0]
                self.active_device = DeviceManager(dev)
                self.devices[dev.serial] = self.active_device

            # 4. Restart measurement system
            self.active_device.start_measurement(self.interval)
            
            # Reconnect signals
            self.measurement_thread = self.active_device.measurement_thread
            self.measurement_thread.update_signal.connect(self.update_measurements)
            self.measurement_thread.error_signal.connect(self.handle_device_error)

            # 5. Update UI
            self.handle_device_connection(True, f"Reconnected: {self.active_device.serial}")
            self.toggle_button.setEnabled(True)
            
            # Update device dropdown
            self.device_combo.clear()
            for serial in self.devices:
                self.device_combo.addItem(serial)
            self.device_combo.setCurrentText(self.active_device.serial)

        except Exception as e:
            self.handle_device_connection(False, f"Reconnect failed: {str(e)}")

if __name__ == "__main__":
    app = QApplication([])
    try:
        window = BatteryTester()
        window.show()
        app.exec_()
    except Exception as e:
        import traceback
        traceback.print_exc()
        QMessageBox.critical(None, "Fatal Error", f"Application failed: {str(e)}")