Custom keyboard

This is my custom keyboard, using a set of 3 Raspberry PI Pico W. One for each node and another serving as the usb dongle. The dongle acts as the BLE central while each node acts as BLE peripheral.

The WiFi is enabled too, for updating the program. For that the dongle also starts a wifi access point for a limited time (10 minutes) at start up. However, the nodes by default doesn't start the wifi mode. But, keeping any key pressed at power on, will make start the wifi and connect to this access point. Then, the new program can be sent over TCP from any computer by connecting the same access point.

The left node, includes the LCD display to enbale a basic UI for adjusting the settings. The right node, includes the trackball for mouse inputs. The settings are stored on a flash chip addd to the dongle unit.

Each node has separate LEDs under each key. I need to find good keycaps for best use of them, though not a priority.

Hardware components

Dongle

• 1 x Raspberry PI Pico W
• 1 x 4 MB Flash (W25Q32) for storing settings
• 4 x 10 KΩ resistors (for flash pull ups)
• 2 x 5 KΩ resistors (for LED)
• 1 x pushbutton switch (reset button)
• 2 x LEDs (indicate connection status to left/right node)
• 1 x USB A male socket (convert the picow to dongle)

Left Node

• 1 x Raspberry PI Pico W
• 42 x diodes
• 42 x key hotswap sockets
• 42 x WS2812 5mmx5mm leds for keys backlight
• 1 x 1.54" LCD 240x240 65K RGB by Waveshare
• 1 x RTC DS3231 (clock with own battery)
• 1 x pushbutton switch (reset button)
• 1 x LED (Numlock/connection status)
• 1 x 3.3V to 5V logic converter
• 10 x 10 KΩ resistors (pull ups)
• 1 x 500 Ω resistor (series resistor for the WS2812 led chain)
• 1 x 5 KΩ resistor (for LED indicator)
• 2 x 7x2 pin FRC female connector
• 1 x 14 pin FRC cable with both side 7x2 pin FRC male connector
• 8 bit header pins
• 1 x 3mmx7mm double sided perforated board
• 1 x 1000 µF capacitor for key backlight leds
• 1 x 470 µF capacitor on 3.3V output from Pico
• 1 x 2A 5V output BMS 1S and a 3.7V LiPo battery
• ample amount of magnet wire for the wiring

Right Node

• 1 x Raspberry PI Pico W
• 42 x diodes
• 42 x key hotswap sockets
• 42 x WS2812 5mmx5mm leds for keys backlight
• 1 x PMW3389 motion sensor for track ball
• 1 x pushbutton switch (reset button)
• 1 x LED (Capslock/connection status)
• 1 x 3.3V to 5V logic converter
• 10 x 10 KΩ resistors (pull ups)
• 1 x 500 Ω resistor (series resistor for the WS2812 led chain)
• 1 x 5 KΩ resistor (for LED indicator)
• 2 x 7x2 pin FRC female connector
• 1 x 14 pin FRC cable with both side 7x2 pin FRC make connector
• 8 bit header pins
• 1 x 3mmx7mm double sided perforated board
• 1 x 1000 µF capacitor for key backlight leds
• 1 x 470 µF capacitor on 3.3V output from Pico
• 1 x 2A 5V output BMS 1S and a 3.7V LiPo battery
• ample amount of magnet wire for the wiring

Dependency

Install build tools (Archlinux)

sudo pacman -Syu base-devel cmake
sudo pacman -Sy arm-none-eabi-binutils arm-none-eabi-gcc arm-none-eabi-newlib

Submodules

Download the submodules

• pico-sdk
• pico_fota_bootloader

git submodule update --init --recursive

TODO

Need to update the wiring diagrams, which are still the old ones used for the two node wired version. Since, now I am using the wireless mode, and removed a few redundant hardware components, the wiring is much simpler now.