MiniAcid is a tiny acid groovebox for the M5Stack Cardputer. It runs two squelchy TB-303 style voices plus a punchy TR-808 inspired drum section on the Cardputer's built-in keyboard and screen, so you can noodle basslines and beats anywhere.

• Two independent 303 voices with filter/env controls and optional tempo-synced delay
• 16-step sequencers for both acid lines and drums, with quick randomize actions
• Live mutes for every part (two synths + eight drum lanes)
• On-device UI with waveform view, help pages, and page hints

1. Flash miniacid.ino to your M5Stack Cardputer ADV (Arduino IDE/PlatformIO).
2. Use the keyboard shortcuts below to play, navigate pages, and tweak sounds.
3. Stopping play (SPACE) triggers saving to the Cardputer's SD Card automatically, if there's an SD card inserted.
4. Jam, tweak synths, sequence, randomize, and mute on the fly

• Transport: SPACE or Cardputer BtnA toggles play/stop. K / L BPM down/up.
• Navigation: [ / ] previous/next page. (Press ENTER to dismiss the splash/help.)
• Sequencer randomize: I random 303A pattern, O random 303B pattern, P random drum pattern.
• Sound shaping (on the active 303 page):
  • A / Z cutoff up/down
  • S / X resonance up/down
  • D / C env amount up/down
  • F / V decay up/down
  • M toggle delay for the active 303 voice
• 303 pattern edit pages (A/B): Use the Cardputer arrow cluster (; , . /) or host arrow keys to move between steps and pattern slots; ENTER loads the highlighted pattern. Q..I choose pattern slots 1-8. When a step is focused: Q slide, W accent, A / Z note +1 / -1, S / X octave up/down, BACKSPACE clears the step.
• Drum sequencer page: Use the arrow cluster (; , . /) or host arrows to move. ENTER toggles a hit (or loads the highlighted drum pattern when the pattern row is focused). Q..I pick drum pattern slots 1-8.
• Mutes: 1 303A, 2 303B, 3 kick, 4 snare, 5 closed hat, 6 open hat, 7 mid tom, 8 high tom, 9 rim, 0 clap.

Tip: Each 303 page controls one voice (A on the first knob page, B on the second), and the page hint in the top-right reminds you where you are.