- the code in noise/7 produces a static white noise with a Neotrellis M4 whereas the code in noise/5 does not.
- 5 is using
adafruit-circuitpython-trellis_m4_express-en_US-5.1.0.uf2adafruit-circuitpython-bundle-5.x-mpy-20201205
- 7 is using
adafruit-circuitpython-trellis_m4_express-en_US-7.1.1.uf2adafruit-circuitpython-bundle-7.x-mpy-20220127
screen /dev/tty.usbmodem3201
https://learn.adafruit.com/microcontroller-compatible-audio-file-conversion
PCM 16-bit Mono WAV files at 22KHz sample rate, which is usually best for the current crop of microcontrollers which take WAV files and play them on a speaker.
sox disturbence.wav -r 16000 -c 1 -b 16 disturbence_16000_mono_16bit.wav
gives within one command
Sample rate of 16 kHz (-r 16000), one channel (mono) (-c 1), 16 bits bit depth (-b 16).
sox -r 22000 -c 1 -b 16 <outfile.wav>
http://docs.circuitpython.org/projects/trellism4/en/latest/api.html https://circuitpython.readthedocs.io/en/latest/shared-bindings/audioio/index.html https://learn.adafruit.com/a-logger-for-circuitpython/using-a-logger
http://turbobard.com/ https://freesound.org/ https://wiki.roll20.net/Jukebox
CircuitPython supports any MP3 file you like. We've found that mono and stereo files from 32kbit/s to 128kbit/s work, with sample rates from 16kHz to 44.1kHz. The DAC output on the SAMD51 M4 is just 12-bit so there's not much point in using higher bitrates.
find GDC -type f | head | xargs -I ./convert-mp3.sh
https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Colors/Color_picker_tool https://www.rapidtables.com/web/color/RGB_Color.html