2 layers266.7 × 77 mm
KB Lightbar 1 straight
melonbred/open-source-projects
This is a repository for all open-sourced or available files for my projects. PCBs will typically have their own repository linked in the table below.
146 parts16MIT
2 layers242.9 × 76.2 mm
This is a repository for all open-sourced or available files for my projects. PCBs will typically have their own repository linked in the table below.
- Size
- 242.9 × 76.2 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 118
- Nets
- 78
- Pads
- 474
- Tracks, vias
- 569, 18
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 16 May 2021
- Updated
- 3 Mar 2026
Overview
MB44 is an open-source printed circuit board by melonbred, from the melonbred/open-source-projects repository on GitHub, published under the MIT licence. It is a 2-layer board of 242.9 × 76.2 mm with 118 parts on 78 nets, routed with 569 tracks and 18 vias.
It is built around the ATMEGA32U2-AU. Its parts include 46 diodes, 6 capacitors, 4 resistors, 1 IC and 1 connector. It belongs with the AVR (ATmega, ATtiny) boards of this library.
Main components
1README
README.mdopen-source-projects
Repository for projects by MelonBred
This is a repository for all open-sourced or available files for my projects. PCBs will typically have their own repository linked in the table below. Everything else will probably be found here in this repository but still linked in the tables below.
Keyboards
Project | Description | Available Files | Image |
|---|---|---|---|
| MBLB | 12.5u main cluster + macro column 40% keyboard, rotary encoder support, STM32 microprocessor. | KiCAD, Gerbers, .dxf, .step |  |
| MB-44 | The MB-44 is a 12.75u layout with a fun 65%-esque blocker separating the arrow cluster. | KiCAD, Gerbers, .dxf, .step |  |
| Pegasus | 12.75u 40% keyboard with 0.75u "WKL" blockers | KiCAD, Gerbers, .step, .fbx |  |
| MB-44 v2 | Update to the MB-44 with refreshed case and PCB. | KiCAD, Gerbers, .dxf, .fbx |  |
PCBs
| Project | Description | Available Files | Image |
|---|---|---|---|
| Program Yoink! | 12u main cluster with exploded arrows and macro columm | KiCAD, Gerbers |  |
| SPM1800 | Southpaw compact mini 1800 | KiCAD, Gerbers |  |
| kb-daughterboard | USB-C daughterboard with ESD, overcurrent and overvoltage protection. 2 versions available - USB-C receptacle flush with PCB and protruded | KiCAD, Gerbers, .step |  |
Miscellaneous
| Project | Description | Available Files | Image |
|---|---|---|---|
| MB-44 Plates | Plate files for the MB-44 keyboard | .dxf | |
| Encoder Knob | Generic knob that fits EC11 encoders. 3d printable. | .step, .stl |  |
Parts
118| Qty | Value | Footprint | References |
|---|---|---|---|
| 45 | SOD-123 | Diode SMD:D_SOD-123 | D1, D2, D10, D11, D12, D13, D14, D15, D16, D17, D18, D19, D20, D21, D22, D23 +29 |
| 41 | MX-NoLED | MX_Only:MXOnly-1U-NoLED | MX1, MX2, MX10, MX11, MX14, MX15, MX16, MX17, MX18, MX19, MX20, MX21, MX22, MX23, MX26, MX27 +25 |
| 3 | Rotary_Encoder_Switch | Rotary_Encoder:RotaryEncoder_Alps_EC11E-Switch_Vertical_H20mm | ENC1, ENC2, ENC3 |
| 2 | 0.1uF | Capacitor:C_0805_2012Metric | C4, C5 |
| 2 | 10k | Resistor_SMD:R_0805_2012Metric | R1, R2 |
| 2 | 22 | Resistor_SMD:R_0805_2012Metric | R3, R4 |
| 2 | 22pF | Capacitor:C_0805_2012Metric | C1, C2 |
| 2 | MX-NoLED | MX_Only:MXOnly-1.25U-NoLED | MX13, MX44 |
| 2 | MX-NoLED | MX_Only:MXOnly-3U-ReversedStabilizers-NoLED | MX49, MX50 |
| 2 | MX-NoLED | MX_Only:MXOnly-1.75U-NoLED | MX12, MX25 |
| 2 | MX-NoLED | MX_Only:MXOnly-2.25U-ReversedStabilizers-NoLED | MX46, MX52 |
| 2 | MX-NoLED | MX_Only:MXOnly-2.75U-ReversedStabilizers-NoLED | MX48, MX51 |
| 1 | 10uF | Capacitor:C_0805_2012Metric | C6 |
| 1 | 16Mhz | Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm | Y1 |
| 1 | 1uF | Capacitor:C_0805_2012Metric | C3 |
| 1 | 500mA | Fuse:Fuse_1206_3216Metric | F1 |
| 1 | ATmega32U2-AU | Package_QFP:LQFP-32_7x7mm_P0.8mm | U1 |
| 1 | Conn_01x04 | random-keyboard-parts:JST-SR-4 | J1 |
| 1 | LOGO | silk:turtle_pan | G*** |
| 1 | MX-NoLED | MX_Only:MXOnly-1.5U-NoLED | MX24 |
| 1 | MX-NoLED | MX_Only:MXOnly-6.25U-ReversedStabilizers-NoLED | MX40 |
| 1 | SOD-123 | Diode_SMD:D_SOD-123 | D46 |
| 1 | SW_Push | random-keyboard-parts:SKQG-1155865 | SW1 |
Questions
How big is the MB44 PCB?
It measures 242.9 × 76.2 mm and has 2 copper layers, 1.6 mm thick.
What parts does the MB44 use?
118 parts, built around the ATMEGA32U2-AU. 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 MB44 KiCad files?
From the melonbred/open-source-projects repository on GitHub, at the commit this page was made from: the board is keyboards/mb44/kicad/MB44.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the MB44 design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
More from melonbred/open-source-projects
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