2 layers65.2 × 22.9 mm
Adafruit Feather 32u4 Bluefruit LE
rambip/splitboard
A real split keyboard: pcb files, code and more
40 parts3
2 layers222.9 × 95.3 mm
Splitboard
rambip/splitboard3A real split keyboard: pcb files, code and more
- Size
- 222.9 × 95.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 158
- Nets
- 169
- Pads
- 618
- Tracks, vias
- 1,008, 301
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 21 Apr 2021
- Updated
- 5 Nov 2021
Overview
Splitboard is an open-source printed circuit board by rambip, from the rambip/splitboard repository on GitHub. It is a 2-layer board of 222.9 × 95.3 mm with 158 parts on 169 nets, routed with 1,008 tracks and 301 vias.
It is built around the ATMEGA32U4-MU, MCP73831T-2ACI/OT-HXY and MBR120. Its parts include 68 resistors, 48 switches, 9 capacitors, 6 ICs and 6 diodes. It belongs with the keyboards and input boards and the AVR (ATmega, ATtiny) boards of this library.
Main components
3README
README.mdSplitboard
This is the ressources we use to create our split, type matrix, bluetooth, mecanical custom keyboard.
Still in construction !
We used a lot of different technologies (solidworks for example), so you probably will not be able to recreate exactly the same keyboard.
But we added ressources you can use if you want to make your own !
Description
pcb + 3d-printed box + aluminium plate + brown switches + adafruit feather 32u4
Design goals:
-
comfortable Ergonomics was the first goal of this model. Even if we had to make tradeoffs, the first choices (2 parts, mechanical switches, design of a new layout) were made to increase comfort.
-
portable It is a tiny keyboard: 46 keys, measure less than 24x12 cm Every key has to be reachable without moving your hands at all !
-
robust I didn't broke it yet !
-
usb and bluetooth You can use it with any computer (mac or pc) and any modern smartphone
Our keyboard supports usb and bluetooth (BLE) communication with the hid specification.
Content:
- board design, with all components (kicad and gerber files) →
pcb - ready to print STL files →
printing - 3d modeling of the entire keyboard (solidworks and .step) →
3d - arduino code for card →
code
3d structure:
-
box
-
pcb
-
plate
-
switches
We chose the cherry mx brown.
Pro tip: Before buying, try to find a second-hand broken keyboard somewhere !
PCB and electronics:
We used the adafruit 32u4.
Go check out their github account, they have a lot of cool stuff !
Software:
Arduino
you can test our sketches if you have a 32u4 adafruit feather.
linux with arduino-cli:
First, make sure you are part of the uucp group.
If not, use the command gpasswd -a $USER uucp
arduino-cli core install adafruit:avr
find the board connected to usb (look at the Port path):
arduino-cli board list
arduino-cli board attach adafruit:avr:feather32u4
arduino-cli compile
arduino-cli upload
Ressources:
https://wiki.osdev.org/USB_Human_Interface_Devices
TODO:
- convert all 3d modeling to .step
- add links to documentation
Parts
158| Qty | Value | Footprint | References |
|---|---|---|---|
| 50 | R | Resistors_SMD:R_0603_HandSoldering | R1, R2, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23 +34 |
| 46 | SW_Push_LED | splitboard:SW_Cherry_MX_1.00u_Plate_led | SW1, SW2, SW10, SW11, SW12, SW13, SW14, SW15, SW16, SW17, SW18, SW19, SW20, SW21, SW22, SW23 +30 |
| 8 | M3 | splitboard:screwhole | Hole, Hole, Hole, Hole, Hole, Hole, Hole, Hole |
| 3 | 100K | Adafruit Feather 32u4 Bluefruit LE:0603-NO | R103, R106, R109 |
| 3 | 10µF | Adafruit Feather 32u4 Bluefruit LE:0805-NO | C3, C6, C8 |
| 3 | 1uF | Adafruit Feather 32u4 Bluefruit LE:0603-NO | C4, C7, C14 |
| 3 | 2.2K | Adafruit Feather 32u4 Bluefruit LE:0603-NO | R101, R107, R110 |
| 3 | 65 | Resistors_SMD:R_0603_HandSoldering | R56, R57, R58 |
| 3 | 65 | Resistor_SMD:R_0201_0603Metric_Pad0.64x0.40mm_HandSolder | R51, R52, R53 |
| 2 | 10k | Resistors_SMD:R_0603_HandSoldering | R54, R55 |
| 2 | 22 | Adafruit Feather 32u4 Bluefruit LE:0603-NO | R104, R105 |
| 2 | C | Capacitors_SMD:C_0603_HandSoldering | C1, C2 |
| 2 | LED_RGB | LED_SMD:LED_WS2812_PLCC6_5.0x5.0mm_P1.6mm | D1, D2 |
| 2 | Q_NPN_BCE | TO_SOT_Packages_SMD:SOT-23 | Q1, Q2 |
| 2 | RED | Adafruit Feather 32u4 Bluefruit LE:CHIPLED_0805_NOOUTLINE | D3, L1 |
| 2 | SWDIO | Adafruit Feather 32u4 Bluefruit LE:PAD-1.5X2.0 | TP102, TP103 |
| 2 | TCA9555DBR | Package_SO:SSOP-24_5.3x8.2mm_P0.65mm | U1, U2 |
| 1 | 10K\ | Adafruit Feather 32u4 Bluefruit LE:0603-NO | R108 |
| 1 | 10uF | Adafruit Feather 32u4 Bluefruit LE:_0805MP | C9 |
| 1 | 1K | Adafruit Feather 32u4 Bluefruit LE:0603-NO | R102 |
| 1 | 8MHz | Adafruit Feather 32u4 Bluefruit LE:RESONATOR-SMD | Y1 |
| 1 | ATMEGA32U4-MU | Adafruit Feather 32u4 Bluefruit LE:TQFN44_7MM | IC1 |
| 1 | BLUE | Adafruit Feather 32u4 Bluefruit LE:CHIPLED_0805_NOOUTLINE | D4 |
| 1 | Conn_02x05_Counter_Clockwise | Pin_Headers:Pin_Header_Straight_2x05_Pitch2.54mm | J1 |
| 1 | Conn_On_Off | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J3 |
| 1 | Conn_droite | Connector_PinHeader_2.54mm:PinHeader_2x02_P2.54mm_Vertical | J2 |
| 1 | MBR120 | Adafruit Feather 32u4 Bluefruit LE:SOD-123 | D5 |
| 1 | MBT40 | Adafruit Feather 32u4 Bluefruit LE:BLE_MODULE_RAYTAC_MDBT40 | U5 |
| 1 | MCP73831T-2ACI/OT | Adafruit Feather 32u4 Bluefruit LE:SOT23-5 | U3 |
| 1 | ORANGE | Adafruit Feather 32u4 Bluefruit LE:CHIPLED_0805_NOOUTLINE | CHG1 |
| 1 | Rotary_Encoder | Rotary_Encoder:RotaryEncoder_Alps_EC12E_Vertical_H20mm | SW50 |
| 1 | SPST_TACT-KMR2 | Adafruit Feather 32u4 Bluefruit LE:KMR2 | SW101 |
| 1 | SPX3819-3.3 | Adafruit Feather 32u4 Bluefruit LE:SOT23-5 | U4 |
| 1 | SWCLK | Adafruit Feather 32u4 Bluefruit LE:PAD-1.5X2.0 | TP101 |
| 1 | microUSB | Adafruit Feather 32u4 Bluefruit LE:4UCONN_20329_V2 | X3 |
| 1 | scl | TestPoint:TestPoint_Pad_D1.0mm | TP2 |
| 1 | sda | TestPoint:TestPoint_Pad_D1.0mm | TP1 |
Questions
How big is the Splitboard PCB?
It measures 222.9 × 95.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Splitboard use?
158 parts, built around the ATMEGA32U4-MU, MCP73831T-2ACI/OT-HXY and MBR120. 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 Splitboard KiCad files?
From the rambip/splitboard repository on GitHub, at the commit this page was made from: the board is pcb/splitboard.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Splitboard design in my own project?
Its repository states no licence, so its author keeps all rights: ask rambip before reusing the design.
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