This project is built with Node.js on Raspberry Pi Zero W. It connects to Positive Grid Spark amp over bluetooth connection and allows users to change preset 1-4 by tapping Up/Down, and turn individual Drive/Mod/Delay on/off by tapping its individual switch, like other commmon multi-effect pedal control apprach.
↓↓↓↓↓ Fun Time ↓↓↓↓↓ (Was originally using RPI Zero W for the proof-of-concept, but switched to esp32 eventually)
Choose either the esp32 or RPI_Zero_W version for your build. I personally has swtiched to esp32.
This project is inspired by Justin's tinderboxpedal project, and Morgan's command list was a great help for verifying my findings.
Well, RPI Zero W is great and offers a lot of possibilities, but there are two things I dislike for this specific use case: 1. ~50 seconds boot time I like my pedal ready to use as soon as possibe after turned on, and I think this 50 seconds booting time was dragging me away from wanna play it. 2. Need safe-shutdown circuit While I had came up with a circuit using 2N5460 P-channel JFET and Adafruit PowerBoost 500 to allow it to safely shutdown, it wasn't the stablest thing. I've found it failed to function as expected a few times especially when the batter power level was low. I think there are ways to improve this, but I was just ready to try the esp32 version