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2 layers486 × 130 mmSimpl slidrr main, the printed circuit board in 3D

Simpl slidrr main

Infecta/simpl-slidrr6

Source files for a CHUNITHM style controller

Size
486 × 130 mm
Copper layers
2
Thickness
1.6 mm
Parts
11
Nets
78
Pads
198
Tracks, vias
337, 39
Pours
2
Routed
Yes
KiCad
KiCad 10.0 (file 20260206)
Created
7 May 2026
Updated
5 Jul 2026

Overview

Simpl slidrr main is an open-source printed circuit board by Infecta, from the Infecta/simpl-slidrr repository on GitHub, published under the GPL-3.0 licence. It is a 2-layer board of 486 × 130 mm with 11 parts on 78 nets, routed with 337 tracks and 39 vias.

It is built around the MPR121QR2. Its parts include 4 ICs and 4 connectors. It belongs with the RP2040 boards of this library.

Main components

1

README

README.md

simpl-slidrr

A cost-effective(ish), Raspberry Pi Pico based controller that aims to perform well while being easy to assemble


Board Overview

About the project

I was looking to build a controller from the projects that were already available but none of them were as accessible due to not being able to 3D print anything among other things. This project aims to make these types controllers more accessible to more people to either improve on or use as-is.

If you want to know more about the firmware itself check out the repo! I'm sorry it's heavily vibecoded I don't know C

[!Warning] I am just a hobbyist maker that has no acedemic qualifications so if there's something that looks off to you please bear this warning in mind.

Also the case design has changed quite a bit but shouldn't affect the final product but any photos of the controller that are used in this README are going to be different.

Build guide

As of writing this, this is a very rough guide for now.


PCB Parts list

This is only for the main PCB, For the air towers refer to whowechina's chu_pico project for the air tower assembly.

ItemDescriptionQuantity
Raspberry Pi PicoThe main MCU for the controller1
MPR121Capacitive touch boards3
USB C Breakout boardSpecifically one like this, Realistically any 4pin, 2.54mm pitch breakout board would probably work but make sure the pinout is the same as in the picture1
XKB Connection TS-1187A-B-A-B ButtonPush buttons for the TEST and SERVICE Buttons2
Horizontal / 90 Degree pin headersFor the Air Wires, 6 pins per side1
Dupont style jumpersFor connecting the Air PCBs to the main PCB1

Case parts list

ItemDescriptionQuantity
Base PartsMain case files, 3mm thickness of any material but acrylic is preferred1
(Optional) Extended Base PieceThis is an extended base which is longer so that the airs are further and lessen the chances of your hands hitting them during play. The base parts are meant to be economical, If you choose this route you can omit/remove this part of the Base file1
Angle bracketCurrently the design only supports 20mm x 20mm x 16mm brackets with these measurements, You'd need to modify the CAD on your own for other bracket sizes and possibly also the following screws needed4
Chicago Screw M5, 7mm longFor mounting the air tower pieces to the base of the case4
Chicago Screw M5, 4mm longFor mounting the air tower pieces to the base pieces themselves4
Chicago Screw M3, 6mm longFor mounting the acrylic stack to the PCB on the bottom half3
Chicago Screw M3, 10mm longFor mounting the acrylic stack to the PCB on the top half with the guard3
Chicago Screw M3, 5mm longFor mounting the air PCBs to the air tower acrylics6

PCB Assembly

Pre-requisites

Cutting the ADDR pads on the MPR121s. As far as I know all the MPR121s ADDR pins are connected to GND. You will need to use an exacto knife or similar to cut the pad on the bottom of the PCB as shown here. Verify the cut with a Multimeter.

Cut ADDR pad

Assembly

  1. Soldering the Pi Pico Soldering the Pi Pico is pretty straight forward aside from the Data test pads on the bottom side of the pico. Depending on your experience in soldering this might be hard, I recommend using a pointed cone tip for this and make sure no air bubbles reside. USB Pad soldering

Credits to whowechina for the image

  1. Soldering the MPR121s I have incorporated a somewhat unique way to solder these due to where these modules sit on the board. Standard Pin headers work but it runs the risk of your finger getting scraped by the sharp ends during play.
    mpr121-mounting

    You'll need a sharp pointed soldering tip to mount these onto the PCB. As for demonstration there is a video on how I soldered these boards.

    Video linked over here

    Notice how the solder sinks down, also check on the side if there's bridges between other pads but mainly to verify the solder has reached the PCB's pads below

    You can also mount the USB-C breakout board the same way

Other than that soldering everything else should be standard.

Case assembly

Once you get the PCB assembled now we can move on to the case assembly.

The case should be assembled like this: Case Assembly Exploded

These are the chicago screw locations for the base Case screw locations

ColorScrew Type
GreenM3*10
RedM3*6
BlueM5*7

And on the Air towers:

Case air tower screw locations

ColorScrew Type
GreenM3*5 **
RedM5*4

**Small side note: You might need washers if the M3 screws are loose

Wires Should be routed through the hole of the air tower piece so that your hands don't get caught on them during play

Regarding Air PCB Placement If you wire the Air PCBs according whowechina's chu_pico guide, you might find that the Airs are reversed. To fix that, switch J2 to the left side and J1 to the right side.

Flash the firmware from whowechina's chu_pico or my fork, simpl-slidrr-firmware

After all that you should (hopefully) have a functioning controller!

Credits and attributions

I want to give my thanks to the Cons&Stuff Discord with help for designing the PCB and whowechina for the chu_pico project! Without it, this project would have never existed.

PCB:

Firmware

Most of the firmware is built on top of whowechina's chu pico firmware.

Parts

11
QtyValueFootprintReferences
3MPR121QR2chu_pico_footprints:MPR121_BOARDU2, U3, U4
2SW_PushButton_Switch_SMD:SW_Push_1P1T_XKB_TS-1187ASERVICE, TEST
1AIR LConnector_PinHeader_2.54mm:PinHeader_1x06_P2.54mm_VerticalJ1
1AIR RConnector_PinHeader_2.54mm:PinHeader_1x06_P2.54mm_VerticalJ2
1Conn_01x04_Pinusb-breakout-board:usb-c-breakoutJ4
1Ground Sliderskogaby-skogaslider-touchpads:PadsJ3
1LOGOLOGOG***
1PicoMCU_RPi-Pico:RPi_Pico_SMD_THU1

Questions

How big is the Simpl slidrr main PCB?

It measures 486 × 130 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Simpl slidrr main use?

11 parts, built around the MPR121QR2. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Simpl slidrr main KiCad files?

From the Infecta/simpl-slidrr repository on GitHub, at the commit this page was made from: the board is PCB/simpl-slidrr_main.kicad_pcb and its schematic PCB/simpl-slidrr_main.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Simpl slidrr main design in my own project?

Its repository publishes it under the GPL-3.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).

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