0x513 by Dave Gold / https://513.ooo/0x513

YOUR OWN ALERT SOUNDS

Put mp3 files with these names in this "data" folder, then in Arduino IDE run
"Upload LittleFS to Pico/ESP8266/ESP32" (Cmd+Shift+P / Ctrl+Shift+P; close the Serial Monitor first).
No need to upload the firmware again. A file that is missing simply falls back to the next one.

  up.mp3            every rise          (used when a type has no file of its own)
  down.mp3          every fall
  spike_up.mp3      sharp rise, 10 s .. 5 min
  spike_down.mp3    sharp fall
  trend_up.mp3      steady rise, 15 min
  trend_down.mp3    steady fall
  big_up.mp3        big rise, 1 h / 4 h
  big_down.mp3      big fall
  high.mp3          a new 24 h high
  low.mp3           a new 24 h low
  wall_up.mp3       a wall broken upwards
  wall_down.mp3     a wall broken downwards

Order for each alert: its own file -> up.mp3 / down.mp3 -> the built-in sound.
Any ordinary mp3 works (mono or stereo, any bitrate); keep each under 6 s
(longer files are cut at 6 s). The up.mp3 and down.mp3 here are the built-in
sounds, as examples. To go back to the built-in sounds: empty this folder and upload again.
The log shows what was loaded: [sound] up.mp3: 1.2 s (44100 Hz, stereo)
