It feels like ages since I built this pedal now and I’ve finally gotten around to writing up how I got it done.
My starting ambitions were fairly simple – a small Arduino, a couple of momentary switches and a relay to control the signal sent to the amp through the TRS cable. I’d planned to add in a 7 segment LCD to provide an update of the currently selected channel.
I structured my experiments to tackle a small bit of functionality at a time, gradually planning to combine each experiment into the finished set of code:
- Have the Arduino connect to the relay and cycle through each switch configuration
- Hook the relay up to a mono socket and cycle the amp through each of its 4 channels
- Hook the LCD to the Arduino and display a “Hello World” message
- Use the relay script to send specific values to the LCD to reflect the selected channel
- Combine the relay and LCD programmes to actually switch the amp channels and display the correct info on the LCD
- Have the Arduino detect button presses using the onboard LED
- Have the Arduino convert button presses into relay switch configurations
- Combine everything so the button presses trigger relay switches and the LCD updates
Each of these tests worked really well and I was impressed with how intuitive the coding process was, especially using the examples bundled into the IDE. I was contemplating getting this boxed up and being done with it but I got ambitious and decided to take things even further.
So, the new plan is to extend what I’ve currently got to give me:
- 4 momentary switches – one for each channel of the amp
- A 16×2 LCD display module to show current settings
- A snazzy little loading screen with customised BOSS artwork
- A memory of what the last setting was before the pedal was switched off
- The ability to set a channel as a momentary option