2 layers44.5 × 82 mm
2 layers285 × 94.6 mm
DIY keyboard from scratch for school projects.
- Size
- 285 × 94.6 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 156
- Nets
- 108
- Pads
- 814
- Tracks, vias
- 1,535, 164
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 10 Feb 2026
- Updated
- 15 May 2026
Overview
Jam1 is an open-source printed circuit board by MRM1790, from the MRM1790/Simple-Keyboard-Project repository on GitHub. It is a 2-layer board of 285 × 94.6 mm with 156 parts on 108 nets, routed with 1,535 tracks and 164 vias.
It is built around the ATMEGA32U4-AU and MIC5219-2.5YM5. Its parts include 67 switches, 63 diodes, 8 capacitors, 7 resistors and 2 ICs. It belongs with the keyboards and input boards and the AVR (ATmega, ATtiny) boards of this library.
Main components
2
ATMEGA32U4-AU
QFP-44(10x10)-40℃~+85℃ 10bit 16MHz 1KB 2.5KB 2.7V~5.5V 26 32KB 8 Bit AVR Built-in FLASH QFP-44(10x10) Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
MIC5219-2.5YM5
SOT-23-5-40℃~+125℃ 1 12V 2.5V 500mA 600mV@(500mA) 75dB@(120Hz) Fixed Over Current Protection、Over Temperature Protection、Enable、Surge Protection Positive SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSMicrochip TechnologyVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
README
README.mdSimple-Keyboard-Project
DIY keyboard from scratch for school projects. This block diagram displays what parts are considered using in this project. As the following goes, Key switches (Kailh or cherry MX) it is possible to use Choc switches (boxed switches) but for now we are sticking to kailh or cherry mx switches. We are using 3 pin switches for this project. For proof of concept, we have thought about doing a cardboard box with a "WSAD" arrow keys for now. Eventually we will do a full 74 keyboard switches. Microcontroller we plan on using is an Arduino pro micro controller that has a USB C connection for the wire to be connected to the computer or laptop. The goal is to have a keyboard matrix which are key switches that have diodes and wires soldered on each other to create columns and rows to utilize more of the pins that are on the Arduino Pro Microcontroller. Once that is set up then the user should be able to press a input on the proof of concept model and should display either numbers or letters to the output display monitor.
ATTENTION: For the BOM files, designators, and CPL we recommended ordering through JLC PCB since it is configured in their version of excel and ordering process. QMK Toolbox will be needed to upload the code in the circuit board which a link will be provided here https://qmk.fm/toolbox
ATTENTION: THE SOFTWARE FOR THE KEYBOARD IS LABELED AS BOTH "KEYBOARD.JSON" AND "KEYMAP C" AND THE MAIN THING THAT YOU WILL NEED IS THE FILE THAT SAYS "jam61_default.HEX" then you will plug that into the QMK Toolbox application, and press the reset button on the circuit board in order to flash it. Once you hit the reset button in Toolbox hit flash prompt and the Hex file will go into the circuit.
Parts
156| Qty | Value | Footprint | References |
|---|---|---|---|
| 62 | 1N4148 | Diode_SMD:D_SOD-123 | D1, D2, D10, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D21, D22, D23 +46 |
| 4 | Stabilizer | Hotswappable:Stabilizer_MX_2.00u | SW64, SW66, SW68, SW70 |
| 3 | 1uF | Capacitor_SMD:C_0805_2012Metric | C1, C4, C7 |
| 3 | VAL** | hole:PKRH | HOLE, HOLE, HOLE |
| 2 | 10K | Resistor_SMD:R_0805_2012Metric | R5, R7 |
| 2 | 10uF | Capacitor_SMD:C_0805_2012Metric | C5, C6 |
| 2 | 22ohms | Resistor_SMD:R_0805_2012Metric | R3, R4 |
| 2 | 22pF | Capacitor_SMD:C_0805_2012Metric | C2, C3 |
| 2 | 5.1K | Resistor_SMD:R_0805_2012Metric | R1, R2 |
| 2 | Alt | Hotswappable:Hotswap_MX_Plated_1.00u | SW56, SW58 |
| 2 | Ctrl | Hotswappable:Hotswap_MX_Plated_1.00u | SW54, SW61 |
| 2 | VAL** | hole:PKRHSL | HOLE, HOLE |
| 2 | Windows | Hotswappable:Hotswap_MX_Plated_1.00u | SW55, SW60 |
| 1 | '" | Hotswappable:Hotswap_MX_Plated_1.00u | SW40 |
| 1 | -_ | Hotswappable:Hotswap_MX_Plated_1.00u | SW12 |
| 1 | 0) | Hotswappable:Hotswap_MX_Plated_1.00u | SW11 |
| 1 | 0.1uF | Capacitor_SMD:C_0805_2012Metric | C8 |
| 1 | 1! | Hotswappable:Hotswap_MX_Plated_1.00u | SW2 |
| 1 | 16MHZ | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | 1Kohms | Resistor_SMD:R_0805_2012Metric | R6 |
| 1 | 2@ | Hotswappable:Hotswap_MX_Plated_1.00u | SW3 |
| 1 | 3# | Hotswappable:Hotswap_MX_Plated_1.00u | SW4 |
| 1 | 4$ | Hotswappable:Hotswap_MX_Plated_1.00u | SW5 |
| 1 | 5% | Hotswappable:Hotswap_MX_Plated_1.00u | SW6 |
| 1 | 500mA | Fuse:Fuse_1206_3216Metric | F1 |
| 1 | 6^ | Hotswappable:Hotswap_MX_Plated_1.00u | SW7 |
| 1 | 7& | Hotswappable:Hotswap_MX_Plated_1.00u | SW8 |
| 1 | 8* | Hotswappable:Hotswap_MX_Plated_1.00u | SW9 |
| 1 | 9( | Hotswappable:Hotswap_MX_Plated_1.00u | SW10 |
| 1 | :; | Hotswappable:Hotswap_MX_Plated_1.00u | SW39 |
| 1 | <. | Hotswappable:Hotswap_MX_Plated_1.00u | SW50 |
| 1 | =+ | Hotswappable:Hotswap_MX_Plated_1.00u | SW13 |
| 1 | >. | Hotswappable:Hotswap_MX_Plated_1.00u | SW51 |
| 1 | ?/ | Hotswappable:Hotswap_MX_Plated_1.00u | SW52 |
| 1 | A | Hotswappable:Hotswap_MX_Plated_1.00u | SW30 |
| 1 | ATmega32U4-A | Package_QFP:TQFP-44_10x10mm_P0.8mm | U1 |
| 1 | B | Hotswappable:Hotswap_MX_Plated_1.00u | SW47 |
| 1 | BS | Hotswappable:Hotswap_MX_Plated_1.00u | SW14 |
| 1 | C | Hotswappable:Hotswap_MX_Plated_1.00u | SW45 |
| 1 | Caps LK | Hotswappable:Hotswap_MX_Plated_1.00u | SW29 |
| 1 | D | Hotswappable:Hotswap_MX_Plated_1.00u | SW32 |
| 1 | E | Hotswappable:Hotswap_MX_Plated_1.00u | SW18 |
| 1 | Enter | Hotswappable:Hotswap_MX_Plated_1.00u | SW41 |
| 1 | Esc/Acc | Hotswappable:Hotswap_MX_Plated_1.00u | SW1 |
| 1 | F | Hotswappable:Hotswap_MX_Plated_1.00u | SW33 |
| 1 | Function | Hotswappable:Hotswap_MX_Plated_1.00u | SW59 |
| 1 | G | Hotswappable:Hotswap_MX_Plated_1.00u | SW34 |
| 1 | H | Hotswappable:Hotswap_MX_Plated_1.00u | SW35 |
| 1 | I | Hotswappable:Hotswap_MX_Plated_1.00u | SW23 |
| 1 | J | Hotswappable:Hotswap_MX_Plated_1.00u | SW36 |
| 1 | K | Hotswappable:Hotswap_MX_Plated_1.00u | SW37 |
| 1 | L | Hotswappable:Hotswap_MX_Plated_1.00u | SW38 |
| 1 | M | Hotswappable:Hotswap_MX_Plated_1.00u | SW49 |
| 1 | MIC5219-2.5YM5 | Package_TO_SOT_SMD:SOT-23-5 | U2 |
| 1 | N | Hotswappable:Hotswap_MX_Plated_1.00u | SW48 |
| 1 | O | Hotswappable:Hotswap_MX_Plated_1.00u | SW24 |
| 1 | P | Hotswappable:Hotswap_MX_Plated_1.00u | SW25 |
| 1 | Q | Hotswappable:Hotswap_MX_Plated_1.00u | SW16 |
| 1 | R | Hotswappable:Hotswap_MX_Plated_1.00u | SW19 |
| 1 | Red | LED_SMD:LED_0201_0603Metric | D63 |
| 1 | Reset Switch | Button_Switch_SMD:SW_SPST_SKQG_WithStem | SW67 |
| 1 | S | Hotswappable:Hotswap_MX_Plated_1.00u | SW31 |
| 1 | Shift | Hotswappable:Hotswap_MX_Plated_1.00u | SW42 |
| 1 | Shift (Right) | Hotswappable:Hotswap_MX_Plated_1.00u | SW53 |
| 1 | Spacebar | Hotswappable:Hotswap_MX_Plated_1.00u | SW57 |
| 1 | Stabilizer | Hotswappable:Stabilizer_MX_6.25u | SW62 |
| 1 | T | Hotswappable:Hotswap_MX_Plated_1.00u | SW20 |
| 1 | Tab | Hotswappable:Hotswap_MX_Plated_1.00u | SW15 |
| 1 | U | Hotswappable:Hotswap_MX_Plated_1.00u | SW22 |
| 1 | USB_C_Receptacle_USB2.0_16P | Connector_USB:USB_C_Receptacle_HRO_TYPE-C-31-M-12 | J2 |
| 1 | V | Hotswappable:Hotswap_MX_Plated_1.00u | SW46 |
| 1 | VAL** | hole:PKRHC | HOLE |
| 1 | W | Hotswappable:Hotswap_MX_Plated_1.00u | SW17 |
| 1 | X | Hotswappable:Hotswap_MX_Plated_1.00u | SW44 |
| 1 | Y | Hotswappable:Hotswap_MX_Plated_1.00u | SW21 |
| 1 | Z | Hotswappable:Hotswap_MX_Plated_1.00u | SW43 |
| 1 | [{ | Hotswappable:Hotswap_MX_Plated_1.00u | SW26 |
| 1 | |\ | Hotswappable:Hotswap_MX_Plated_1.00u | SW28 |
| 1 | }] | Hotswappable:Hotswap_MX_Plated_1.00u | SW27 |
Similar boards
- 2 layers60 × 100 mm
- 2 layers32.5 × 25.8 mm
PCM5102A
risejohan/2Bit
In this repo we can see some designs with free use for the community, 2 Bit electronic
31 parts17 - 2 layers243.2 × 106 mm
- 2 layers228.4 × 85 mm
LeChiffre
tominabox1/Le-Chiffre-Keyboard
Great thanks goes to Jake at P3D for really making the case amazing and open sourcing his work. Check him out at P3Dstore.com
105 parts183GPL-3.0 - 2 layers228.6 × 76.8 mm
Schwann Rev0.5b
The-Royal/The_Royal_Open-Source-Projects
A Master Repository For All things Royal Made
127 parts159MIT - 2 layers30 × 65 mm
Keyboard mcu
dpapavas/lagrange-keyboard
A configurable, handwired, ergonomic keyboard
26 parts137AGPL-3.0 - 2 layers88.4 × 80 mm
LHS Controller PCB
dmcke5/ZenDeck
This is the second revision of my Mini PC based handheld Gaming PC! It is designed for a Beelink SER 5 Mini PC but could be adapted to other systems by changing the mounting brackets and outlet plate.
76 parts133CERN-OHL-S-2.0
Questions
How big is the Jam1 PCB?
It measures 285 × 94.6 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Jam1 use?
156 parts, built around the ATMEGA32U4-AU and MIC5219-2.5YM5. 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 Jam1 KiCad files?
From the MRM1790/Simple-Keyboard-Project repository on GitHub, at the commit this page was made from: the board is Jam1.kicad_pcb and its schematic Jam1.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Jam1 design in my own project?
Its repository states no licence, so its author keeps all rights: ask MRM1790 before reusing the design.