Something that I’ve been wondering (And this is me not knowing the first thing about building pedals) is if it’s possible to utilize the expression out’s tip ring and sleeve. See, I have a Boss FS-6 pedal that uses TRS for two switches (one tip-sleeve the other ring-sleeve), but since the OWL only uses Tip and sleeve, I can only use one button (the tip-sleeve one) to control a parameter. Is it possible for it to work the way I’m thinking, or do I have something fundamental incorrect?
Tip and Ring on the OWL Pedal go to two pins on the microcontroller called PA2 and PA3 (port A pins 2 and 3), via a pair of resistors. Sleeve is permanently connected to ground.
PA2 and PA3 are configured as one fixed 3.3v output, and one ADC (analogue to digital) input. So the output pin provides a voltage which the the expression pedal divides down to a lower voltage for the ADC to read.
The pins could equally well be configured as digital inputs with internal pull-up resistors enabled. This would mean that when not connected, they will give a high / on value thanks to the pull-ups. When either is shorted to ground/sleeve by a switch, they will read low / off. If we invert the values we get two switches.
tl;dr: yes! but the firmware doesn’t support it (yet)
This might be a common enough use case that we should build it into the firmware as a configurable option.
I’ve opened an issue: OWL Pedal support for foot switch · Issue #25 · pingdynasty/OwlWare · GitHub
Question is: what parameters or buttons will the two switches be mapped to in the patch? One can set parameter E to either 0 or 1, but what about the other switch?
Interesting! I knew I was missing something obvious. So even with the pedal accepting input from both buttons, because they are not mapped as separate parameters, it would do me no good. I guess I’m stuck with one button.
HOWEVER, I have a back-up. Since I only play through one amp, I have no need for the second in and out, meaning I can send a [phasor] in gen through Out 2, and since I have a momentary/latching bypass looper, I can send the signal through that, out through the loop and into In 2 on the Owl and use that to trigger a parameter in the pedal. So there’s always a back up plan!