Probably around two years ago I purchased a Triple USB Foot Pedal (PC Sensor FS2020U1SW) for about AU$40 with the intention to shove an ESP32 into it, and modify the circuitry to turn the pedal into a wireless unit - akin to my Bluetooth MIDI Page Turner project. But hah guess what I never got around to doing it…

… Actually, I did try attempt to start it, but upon inspection it wasn’t really going to fit my intended purpose - and also I would have to retrofit a bunch of other components (which I would have to buy) into the unit. Anyhow for the benefit of anyone wanting to buy this pedal, to either use normally or to mod.

Installation

Teardown

After completely unscrewing the tension screw at the base of the board (this screw can be tightened / loosened to adjust the pedal spring force), we see the internal “circuitry”.

On the left and right pedals, we have a simple lever switch that is routed to the central pedal chamber with a thin ribbon cable.

The central pedal is the heart of all the chaos. Part of the ribbon cable from the left pedal is bridged to the yellow wire, whilst its ground (assumed) is jammed into the ground contact of the central pedal lever switch, along with the ground of the right pedal. The red and green cables also connect to the other switches.

• Yellow - left switch
• Red - centre switch
• Green - right switch
• Black - GND

Now these four wires that go into the external cable obviously aren’t able to handle USB communications - instead the USB controller is contained within the USB housing (I haven’t opened this).

This image found somewhere from the manufacturer’s website shows what’s inside the USB housing.

Modding

I actually wanted to purchase the FS2020U1IR model instead of the FS2020U1SW as the former used photoelectric diodes (silent) instead of momentary micro lever switches (loud[er]). However the eBay product listing which I purchased it from wasn’t clear as to which model I was purchasing. It mentioned the word “silent” - but I guess silence is subjective to the user’s audibility..

Device Logs

[  776.738692] input: HID 1a86:e026 Keyboard as /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.0/0003:1A86:E026.0018/input/input59
[  776.796422] input: HID 1a86:e026 Mouse as /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.0/0003:1A86:E026.0018/input/input60
[  776.797165] input: HID 1a86:e026 as /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.0/0003:1A86:E026.0018/input/input61
[  776.797879] input: HID 1a86:e026 Consumer Control as /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.0/0003:1A86:E026.0018/input/input62
[  776.798358] hid-generic 0003:1A86:E026.0018: input,hidraw9: USB HID v1.11 Keyboard [HID 1a86:e026] on usb-0000:00:14.0-9/input0
[  776.799627] input: HID 1a86:e026 as /devices/pci0000:00/0000:00:14.0/usb1/1-9/1-9:1.1/0003:1A86:E026.0019/input/input63
[  776.799932] hid-generic 0003:1A86:E026.0019: input,hidraw10: USB HID v1.10 Device [HID 1a86:e026] on usb-0000:00:14.0-9/input1

Field Testing

Now again, I never actually got around to modding it - but I did the opportunity to try it out the way it was intended to be used (i.e. as a wired USB foot pedal).
I tried it out during a live performance (electric guitar), connecting the pedal to my laptop that was running Element. The debouncing on this pedal worked great, I never encountered any ghost triggers.
The rest? Well it’s effectively a USB keyboard - it does its job.

If You’re Interested

I had my electric guitar connected to a Steinberg UR22 audio interface that fed my guitar signal into Element, which had some guitar IRs and cabinet simulation plugins running, along with some delay, reverb and chorus effects. The output was fed into a volume pedal, which was then connected to the venue’s sound system.

The footpedal was responsible for enabling certain effects and software pedals during the performance

Configuration

The configurator software (Windows only) allows you to configure what each pedal does.
For simplicity, I had set each pedal to perform a single keypress (i.e. pressing a, b or c)

Some other time in 2020

A few months before I bought USB footpedal, I had purchased this stompbox controller - which was intended to be used to control certain amp cabinets - but I had the idea of reusing the metal case for my own purposes. Safe to say, that also didn’t happen.

Sometime in 2022

In 2022 I ended up buying a (much smaller) Bluetooth Footpedal for the same price! (AU$40)
This device was honestly what I should have bought from the start.

• Wireless
• Has a battery and charging circuit
• Inbuilt MIDI

Using the mobile configurator, I could map each pedal to a different MIDI control change event (or a basic keyboard keypress if I wanted to).
The device has has support for an expression pedal - perhaps I could come up with a use for that!