bhcarpenter
Well-known member
So last night I was contemplating picking up another MIDI loop switcher, or perhaps rolling my own with relays and a microcontroller, when I had an idea. What if the pedals themselves served as the foot switches? Here’s what I’m thinking:
- Each pedal has relay switching with a microcontroller and momentary switch
- The microcontrollers also have a serial communication to a control box and can receive turn on/off commands as well as transmit their current state
- The control box can toggle between three modes:
1. Live mode: The pedals work as “regular” effect pedals without coordination
2.Toggle mode: Turning on a pedal signals the control box, which can then send a “turn off” message to any of the other boxes to bypass them automatically
3. Preset mode: The control box listens to MIDI PC messages from a MIDI controller. When a “save” button is pressed, the control box polls all connected pedals for their current state and saves it to memory. The next time that PC is received, it signals all connected pedals to switch to that saved state.
- The control box would connect to the microcontroller of each pedal using the 1-Wire protocol in a linear topology
- Here’s where it gets really crazy: connect the pedals with TRS plugs, and use the ring for the 1-Wire serial connection.
Some potential issues off the bat:
- Each pedal will somehow have to detect if its output jack has a short between ring and sleeve (i.e. a TS cable was connected) and somehow terminate the data line appropriately
- Sharing audio ground with the 1-wire protocol ground (both on the sleeve) might be a really bad idea
- Could running a digital signal in the same cable cause noise artifacts in the audio path?
Anyway, I’m hoping someone who actually knows what they’re doing will tell me why this is a bad idea before I spend a lot of time trying to make it work.
- Each pedal has relay switching with a microcontroller and momentary switch
- The microcontrollers also have a serial communication to a control box and can receive turn on/off commands as well as transmit their current state
- The control box can toggle between three modes:
1. Live mode: The pedals work as “regular” effect pedals without coordination
2.Toggle mode: Turning on a pedal signals the control box, which can then send a “turn off” message to any of the other boxes to bypass them automatically
3. Preset mode: The control box listens to MIDI PC messages from a MIDI controller. When a “save” button is pressed, the control box polls all connected pedals for their current state and saves it to memory. The next time that PC is received, it signals all connected pedals to switch to that saved state.
- The control box would connect to the microcontroller of each pedal using the 1-Wire protocol in a linear topology
- Here’s where it gets really crazy: connect the pedals with TRS plugs, and use the ring for the 1-Wire serial connection.
Some potential issues off the bat:
- Each pedal will somehow have to detect if its output jack has a short between ring and sleeve (i.e. a TS cable was connected) and somehow terminate the data line appropriately
- Sharing audio ground with the 1-wire protocol ground (both on the sleeve) might be a really bad idea
- Could running a digital signal in the same cable cause noise artifacts in the audio path?
Anyway, I’m hoping someone who actually knows what they’re doing will tell me why this is a bad idea before I spend a lot of time trying to make it work.