WLED-MM backport of upstream wled#4980
RMT High-priority Interrupt driver - solves flickering problems on esp32, esp32-S2 and esp32-S3
do not use the new RMTHI driver on old V3 builds (especially esp32dev_compat)
upgrade all esp32 builds to NeoPixelBus 2.7.9 (we can't go higher due to API incompatibilities)
* separate mutexes for improved performance:
- busses.show and effect drawing
- critical changes to segment vector
- block out critical segment changes while strip.service() loops over segments
* UDP realtime acquires mutex before drawing
- prevents corrupted outputs, caused by parallel tasks updating pixels while busses.show() runs
revised mutex and critical section handling for segment drawing
- simplified code with macros (no more #if ESP32 ... #endif)
- remove some critical sections (prevents interrupt stalling)
- added mutex to functions that change the list of segments
- added mutexes to all (potential) background drawing code
- use recursive mutexes to prevent accidental self-locking of tasks
* protect pixel buffer changes with critical section
* protect segment list modification with critical section
* make _isServicing and _triggered atomic (move out of packed bitarray)
* allow custom timeout for waitUntilIdle - DDP needs a longer timeout
* protect strip.show() and effect drawing functions with mutex, to prevent crashes
* enable ARDUINOJSON_DECODE_UNICODE (otherwise unicode needs 6(!) bytes for encoding)
* robustness: increase a few tiny string buffers for some extra margin
* Web UI: allow entering up to 64 chars as segment name
* mark synchronization variables volatile (thread-safe)
* additional logic in closeFile() to avoid file write while leds are pushed out by NPB driver
* some comments and analysis
* replace "yield()" after file ops with "delay(0)" before operations.
* use a more meaningful max universes limit of 112 (safe up to 128x128 pixels)
* accept more universes, but only track sequences for the configures max universes
* made e131LastSequenceNumber[] local (its only used in e131.cpp)
This disables bus caching (and related speedups) while receiving realtime UDP pixels.
Its still totally unclear to me what happens, and why disabling the cache solves problems.
controls the number of phases shown by the effect
breaking - the old code was using a fixed width per wave, while the new one always fits the same number waves into the panel width.
