Egboard

A column staggered ortholinear keyboard powered by the Raspberry Pi Pico running Rust!

Features

• Mouse Input
• Multiple layers
• 1 kHz polling rate
• One-shot modifiers

Typing Test:

Typing_Test.mp4

Bulding the firmware

Pre-built uf2 is available at releases
Otherwise to build from source:

1. Install rust
2. Download the toolchain for the thumbv6-none-eabi(ARM Cortex-M0+) target
   rustup target add thumbv6-none-eabi
3. Build the firmware elf
   cargo build --release
4. Converting elf to uf2 using elf2uf2-rs
   cargo install elf2uf2-rs
elf2uf2-rs target/thumbv6-none-eabi/release/egboard egboard.uf2
5. A new egboard.uf2 file should be created

Uploading the uf2 to pico:

1. Enter the pico into bootloader mode by holding the Bootsel button
2. Mount the pico's mass storage to the PC's file system (should be done automatically in most Operating Systems)
3. Copy the firmware.uf2 file to the mounted location

Hardware

The hardware files required to generate the top and bottom plates can be found here

Parts required:

Part	Quantity	Description
Raspberry Pi Pico	1	Microcontroller that powers the whole thing
M3 screw	40	Used to mount the top and bottom plates together
M2 screw	4	Used to mount the raspberry pi pico to the top plate
M3 standoff	20	Provide spacing between the top and bottom plate to house the electronics
Switch	38	Key switches mounted to the top plate (both 3-pin and 5-pin work)
Keycaps	38	Keycaps for the switches
Diodes	38	Required to achieve n-key rollover
USB Cable	1	Used to connect the pico to the computer
Bump Switch (optional)	1	Used to get the board to bootloader mode

Matrix Layout:

Connect the switches in a 10x4 matrix with the following layout:

NOTE: The above picture shows the layout from top side, flip it horizontally when doing the wiring with the board upside down.

Wiring:

The diodes should be connected in Column to Row ordering i.e the cathode of the diode (the side with the line) should be facing away from the keys and the cathode of the diodes in same row should all be connected.
The anode of the diodes should each connect to one pin of the switch and the other pin should be connected straight with all the pins of switches in same column. For wiring the Raspberry Pi Pico, the indexing used in wiring diagram above correspond to the pico's pinout as follows:

Row	0	1	2	3
Pin	0	1	2	3

Column	0	1	2	3	4	5	6	7	8	9
Pin	13	12	11	10	9	8	7	6	5	4

Keymap configuration

The keymap for the board is specified in default_keymap.rs file.
Each Keymap can include upto 256 Layers which are added using the add_layer method.
Each Layer comprises of a 30 element array for the finger cluster and 8 element array for the thumb clusters.

Provided default keymap

Layer 0

Layer 1

Layer 2

Layer 3