9x9-PiPico-Keypad

This 9-key macropad is designed using a Raspberry Pi Pico microcontroller programmed with CircuitPython using KMK firmware.

Overview

This repository provides the schematics and code used in this project. The goal of this project was to build a compact, low-cost, and easily programmable marcopad which ultimately serve the purpose of offering quick access to frequently used shortcuts, macros, and commands in a streamlined, tactile form.

Bill of Materials

Item	Quantity	Cost
Macropad PCB	1	$0.40 (Excluding Shipping)
Raspberry Pi Pico	1	$9.95
Mechanical Keyboard Switch	10	$4.89
PBT Blank Keycaps	10	$9.59

PCB

The PCB was designed using KiCAD with a focus on simplicity, compactness, and ease of assembly. It includes all the necessary connections for the microcontroller, switches, and diodes, while minimizing overall footprint and cost.

Files Included:

• .kicad_pcb – Main PCB layout
• .sch – Schematic design

Firmware and Code

This macropad uses KMK Firmware, keyboard firmware written in CircuitPython. KMK is ideal for small custom keyboards and macropads due to its ease of use, real-time reprogrammability, and active development community.

How to Implement:

• Flash the CircuitPython .uf2 file for your board from circuitpython.org
• Drag-and-drop the firmware onto the mounted USB drive (CIRCUITPY)
• Install KMK by copying its files into the lib directory on the device
• Add or edit the code.py file to define your keymap and macros
• Example Code:

import board  # Access pin definitions specific to the microcontroller
from kmk.kmk_keyboard import KMKKeyboard  # Base KMK keyboard class
from kmk.keys import KC  # Keycode library for standard key constants
from kmk.scanners.digitalio import DiodeOrientation  # Diode orientation options for the matrix

# Create a keyboard object instance
keyboard = KMKKeyboard()

# Define the row and column GPIO pins based on your physical wiring
keyboard.row_pins = (board.GP10, board.GP11, board.GP12)  # 3 row pins
keyboard.col_pins = (board.GP6, board.GP7, board.GP8)     # 3 column pins

# Specify the diode orientation used in the matrix (important for correct scanning)
keyboard.diode_orientation = DiodeOrientation.COL2ROW

# Define the keymap layout as a flat list of keycodes (3x3 matrix in this case)
keyboard.keymap = [
    [KC.KP_1, KC.KP_2, KC.KP_3,
     KC.KP_4, KC.KP_5, KC.KP_6,
     KC.KP_7, KC.KP_8, KC.KP_9]
]

# Run the keyboard firmware loop when the script is executed
if __name__ == '__main__':
    keyboard.go()

Feel free to modify the code to suit your own workflow!

Resources

• KiCad Footprints: The component footprints used in this project were sourced from ScottoKeebs.