HexKey60

HexKey60

Just a custom mechanical keyboard project designed by me

Specs

• Layout: 68 keys, 15 columns x 5 rows matrix, ANSI 65% (up arrow between right Shift and Delete, left/down/right arrows on the bottom row, Fn next to AltGr)
• Microcontroller: Raspberry Pi Pico (RP2040), mounted under the spacebar
• LEDs: SK6812MINI-E, one per key, same color across the whole board
• Matrix diodes: 1N4148, one per switch
• USB: routed from the microcontroller (under the spacebar) up to the connector at the top of the case via a Treedix USB-C breakout

Why the Pico and not something smaller

Originally I was going for something more compact (Orpheus Pico, then XIAO RP2040, then RP2040-Zero) because the standard Pico seemed too bulky to fit between the switches. That problem went away once I moved the microcontroller under the spacebar, where there's way more free space, at that point the regular Pico made more sense, i had space to place it and it has enough pins to fit evry component.

Matrix

• Rows: GPIO0-GPIO4
• Columns: GPIO5-GPIO19
• Every switch has its own diode to prevent ghosting

LEDs

Driven via PIO on GPIO21.

LED power comes straight from VBUS (5V), not from the Pico's 3.3V regulator, so the current spikes from 68 LEDs at once don't stress it. Max brightness needs to stay capped in firmware.

USB

The Pico sits under the spacebar, away from the case edge where the connector needs to come out. D+/D- are hand-wired to test points TP2/TP3 on the back of the Pico (not routed through the PCB), going to a Treedix USB-C breakout mounted in the case. CC1/CC2 on the breakout already have pull-down resistors built in, so they're left unconnected.

Plate

The plate and the case are fully 3d printed

Firmware

Live control from a PC over Raw HID (tastiera68_controller.py, requires pip install hidapi):

• change LED color on the fly (persistent, saved to the Pico's emulated EEPROM)
• remap any key without reflashing (also persistent, saved to a dedicated EEPROM area)

Building the firmware

1. Get QMK

If you don't already have a QMK checkout:

git clone https://github.com/qmk/qmk_firmware.git
cd qmk_firmware

Follow QMK's own setup guide once (https://docs.qmk.fm/#/newbs_getting_started) to install the build environment (Python, the ARM toolchain, etc.) if you haven't done that before — it's a one-time setup per PC.

2. Drop this keyboard into the QMK tree

Copy the whole HexKey60 folder into qmk_firmware/keyboards/, so you end up with:

qmk_firmware/
  keyboards/
    HexKey60/
      info.json
      keymaps/
        default/
          keymap.c
          rules.mk

3. Compile

From the qmk_firmware root:

qmk compile -kb HexKey60 -km default

If everything is set up correctly this produces a file called something like HexKey60_default.uf2 in the qmk_firmware root folder.

If the build fails on the EEPROM driver lines in rules.mk (EEPROM_DRIVER / WEAR_LEVELING_DRIVER), check QMK's current docs for the exact driver name used for RP2040 in your checkout's version — the name has changed between QMK releases.

4. Put the Pico into bootloader mode

The RP2040 shows up as a USB mass-storage drive (RPI-RP2) when it's ready to receive new firmware:

1. Unplug the keyboard.
2. Hold down the BOOTSEL button on the Pico (the small white button on the board itself).
3. While still holding it, plug the USB cable back in.
4. Let go of the button — a drive called RPI-RP2 should appear on your computer, the same way a USB flash drive would.

5. Flash

Just drag and drop the .uf2 file you built in step 3 onto the RPI-RP2 drive. The Pico reboots on its own as soon as the copy finishes, and the keyboard should now be running your firmware.

If qmk flash is set up on your system instead, this also works and does the copy for you:

qmk flash -kb HexKey60 -km default