This introduces an optional band pass filtering step to remove low frequency noise. Very effective for PDM mics - reduces noise floor by a factor of 100 !
- I2S DAC devices utilize the complete sample range [-32767 ... 32768], while I2S microphones typically deliver samples in [-2047... 2047]. Down-scaling Line-in samples ensures that filters and AGC operate optimally.
- use aPLL clock source for I2S with MCLK
- experimental: I2S slave mode (however could not get it to work ...)
A few goodies from my development branch, before I continue refactoring so much that I can't extracts nothing anymore.
- GEQ fades a bit slower
- updates to mic profiles
- simple peak detection without FFT (low freqs only)
it's possible that volume samples become negative. In this scenario, our simple noise gate does stupid things, and it looks like "effects temporarily lost the sound".
This fix improves the situation, and makes sure that volume samples are always >= 0.
16kHz might be a good compromise on small MCU's:
- GEQ will show frequencies up to ~6Khz
- FFT process may use up to 32millis (-> 100% CPU load). Try to stay below <60% so FreeRTOS can schedule all tasks properly.
- more CPU time is left for other WLED, so it maintains LED FPS and stays responsive on web UI.
Only run FFT when the result will be used.
Please note that this also means that `FFTTime` shown in Info is only meaningful when there is sound input and not silence.
--> To get exact FFT times, the optimization can be disabled by compiling with `-D SR_DEBUG`
I2S microphones were not working any more in with the newest framework - only delivers silence.
Ther reason is stupid bug in espressif I2S "compatibility" driver: RIGHT and LEFT channel are swapped, so when only asking for LEFT, we get silence from RIGHT.
Workaround: simply change LEFT to RIGHT, until the problem is fixed in ESP-IDF --> Fix tested on "classic ESP32", but still need to check behavior on -S3.
Code compiles also on -S3, -S2, and -C3.
smaller changes:
- a few changes to use new APIs (MCLK, rouing and sample resolution)
- a few additional debug messages
- put correct value into _pinConfig.mck_io_num
- added user-selectable frequency profiles, to allow adjustments for different I2S microphones (including line-in)
- additionally show "GEQ Input Level" as number in percent.
Encapsulated all parts with #ifdef that will not compile on newer ESP32 variants.
It's still a long way to go before we have a working version on -S3 and -C3, bus this should help to get us started.
From MoonModule/WLED repo.
