2 layers103 × 30.5 mm
2 layers92 × 73 mm
MidiKeypad
LeonOmo/MidiKeyPad-OMOThe MidiKeypad is circuit board built around the ESP32-S3-Zero created to serve as a pocket sized MIDI input device for sound generation.
- Size
- 92 × 73 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 9
- Nets
- 18
- Pads
- 62
- Tracks, vias
- 133, 0
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 21 Oct 2026
- Updated
- 27 Oct 2026
Overview
MidiKeypad is an open-source printed circuit board by LeonOmo, from the LeonOmo/MidiKeyPad-OMO repository on GitHub. It is a 2-layer board of 92 × 73 mm with 9 parts on 18 nets, routed with 133 tracks and 0 vias.
Its parts include 4 switches, 1 IC and 1 connector. It belongs with the ESP32 boards of this library.
README
README.mdMidiKeyPad-OMO
What is this project?
The MidiKeypad is circuit board built around the ESP32-S3-Zero created to serve as a pocket sized MIDI input device for sound generation.
What does it do?
The Midi Keypad OMO is a version of Kais Midi Keypad but with a few changes. Build around the Waveshare ESP32-S3-Zero
- Microcontroller: Waveshare ESP32-S3-Zero
- Switches: For instrument choice (preset change)
- Rotary Encoder: Tempo adjustments
- Slide Potentiometers: For volume controller
- Midi Controlls: Exposed copper for note input (7 Playable Notes)
Why does it exist?
- Just for the love of the game?: My intentions behind making this was for the pure joy i get from designing / soldering / wiring
Bill of Materials
| Designator | Component | LCSC Number / Link | Amount | Total Price | Description |
|---|---|---|---|---|---|
| U1 | ESP32-S3-Zero | https://www.aliexpress.com/ssr/300000512/BundleDealsDutyCovered | 1x | 5,17 € / 5,79 $ | The Brain |
| RV1-2 | Potentiometer Bourns PTA1543 Single Slide | https://de.aliexpress.com/item/1005007386348713.html | 2x | 6,10 € / 6,83 $ | Sliding Potentiometer for volume control |
| SW1-3 | Kailh Choc Low Profile Switch | https://de.aliexpress.com/item/1005011812200097.html | 3x | 7,61 € / 8,52 $ | For switching between presets / instruments |
| SW4 | EC11 Rotary Encoder | https://de.aliexpress.com/item/1005008716778661.html | 1x | 2,69 € / 3,01 $ | Used to control and adjust the tempo |
| PCB | PCB | JLCPCB | 1x | 4,00 $ | The PCB |
| Total Price | 28,15 $ | ||||
| Shipping | JLPCB 6,04 $ | ||||
| Total price with shipping | 34,19 $ |
Tools
- PCB Design: KiCAD
- Case Design: Onshape
- Firmware: Arduino IDE (C++) (Very likely)
Schematic
The Schematics in KiCAD
PCB
The PCB in KiCAD
Case
Extra
Yes i know i should be more creative with projects like these but Kais version is just so amazing that i wanted to make a similar one. At this project, Im most proud of my PCB wiring as it is way cleaner than my lasts and you can just see where what is going where.
Bonus
Before i saw the Midi Keypad i wanted to make "MusicMaker!" which is probably a future project of mine. The MusicMaker! will be sort of the same but i will use a buzzer / noise output to make noise and also it will have batteries.
Parts
9| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | SW_Push | Hackclub Footprints:Kailh Choc Low-Profile Switches | SW1, SW2, SW3 |
| 2 | R_Potentiometer_MountingPin | Potentiometer_THT:Potentiometer_Bourns_PTA1543_Single_Slide | RV1, RV2 |
| 1 | Capacitive Touch Buttons | Capacitive Circles:Capacitive Circles | J1 |
| 1 | LOGO | Bilder:Grimas | G*** |
| 1 | RotaryEncoder_Switch_MP | Rotary_Encoder:RotaryEncoder_Alps_EC12E_Vertical_H20mm | SW4 |
| 1 | Waveshare ESP32-S3-ZERO | Hackclub Footprints:Waveshare ESP32-S3-Zero | U1 |
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Questions
How big is the MidiKeypad PCB?
It measures 92 × 73 mm and has 2 copper layers, 1.6 mm thick.
What parts does the MidiKeypad use?
9 parts. 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 MidiKeypad KiCad files?
From the LeonOmo/MidiKeyPad-OMO repository on GitHub, at the commit this page was made from: the board is PCB/MidiKeypad.kicad_pcb and its schematic PCB/MidiKeypad.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the MidiKeypad design in my own project?
Its repository states no licence, so its author keeps all rights: ask LeonOmo before reusing the design.