Introduction

The MarcoPad is a compact 3x3 keys macropad built with RP-2040 Zero

It's built using the RP-2040 Zero as MCU, Choc mechanical keyboard switches, SK6812 MINI-E RGB LEDs for backliting (optional) and simple discrete electronic components.

The original design is composed of a 3D printed base, a custom PCB, a laser-cut acrylic faceplate, and laser-cut acrylic keycaps.

The excellent QMK Firmware is used to control the function keys and the backlight.

Hardware

PCB

Component list

• 1x RP-2040 Zero
• 9x Choc
• 9x 1N4148 (DO-35 package) diodes

(Optional) Backlight component list

• 1x 330Ω (SMD package 1206) resistor
• 9x SK6812 MINI-E RGB (alternativelly WS2812B 6028 can also be used)

Base

I've custom designed a base which can be 3D printed using PLA, Resin or other materials.

Find the 3mf file here.

Faceplate

I've custom designed a faceplate for laser cutting.

Find the svg file here.

Key caps

I use the cutouts of the faceplate as keys, but obviously you can design your own keys or adjust the faceplace to fit standard Choc keycaps which is widely available online.

For the key illustrations, I've printed images on stickers.

Software

Initial Setup

The MarcoPad uses the QMK as the firmware to control the function keys and the backlit.

Basic setup

Follow QMK's instructions for Prerequisites, Preparing your environment and Setting up QMK.

Entering flashing mode

The first time you connect the MarcoPad to your computer, your should see a volume/drive named "RPI-RP2".

If it's not showing up, try pressing and holding the BOOT button, then short press the RESET button on the RP2040 Zero.

If the issue persists, you problem might be with the hardware itself, connections or soldering. Please check everything.

Flashing the firmware

Once installed, go to QMK's home folder:

Flash the firmware:

✅ Done, your MarcoPad is ready for use.

By default, the keys are mapped to 1-9, try them out to make sure everything works.

Keymap configuration

QMK is very flexible, extensible and configurable. You can explore the QMK's documentation for advanced setup.

To start you'll want to at least assign a key/function to each key.

Create a new keymap without backlit

The new keymap is based on the default keymap, without backlit enabled. If you opted for adding backlit, use the next option

Create a new keymap with backlit enabled

Edit the layout

Edit the keyboards/marcopad/keymaps/[your keymap name]/keymap.c file.

You'll now replace the key mappings in the following section of the file:

[0] = LAYOUT_ortho_3x3(
                        KC_P7,   KC_P8,   KC_P9,
                        KC_P4,   KC_P5,   KC_P6,
                        KC_P1,   KC_P2,   KC_P3
                     )

For each entry in the "matrix", replace with one of the available keycodes.

You can also use modifier keys and other QMK features to define the key's function.

For instance, if you want be bottom-left key (currenty KC_P1) to function as "copy", replace KC_P1 for LCMD(KC_C) on macos or LCTL(KC_C) on Windows. The "paste" command would be CMD(KC_V) on macos or LCTL(KC_V) on Windows.

Flash your custom firmware:

✅ Done, your MarcoPad is ready for use.