Custom Macropad for League of Legends

Overview

This project implements a custom USB macropad using the Raspberry Pi Pico W. The macropad is designed for League of Legends, providing dedicated QWER ability keys, FG keys, and a future joystick expansion for character movement using League's new WASD support. The firmware is written in C using the Raspberry Pi Pico SDK, and the final hardware will be designed in KiCad and manufactured as a custom PCB.

Project Roadmap

• Prototype button circuit on a breadboard
• Test each switch and verify wiring
• Develop firmware for button detection and debouncing
• Implement USB HID keyboard functionality
• Add macro support
• Design the schematic in KiCad
• Route and manufacture the PCB
• Assemble and test the final board
• Design and print a case

Technologies

• C
• CAD (3D Printed Case)
• Raspberry Pi Pico SDK
• TinyUSB
• KiCad
• Git
• VS Code

Button Module Specifications

Purpose

The button module provides an interface for initializing and scanning the macropad's pushbuttons. It abstracts the GPIO hardware and reports button press and release events.

Functional Requirements

• Initialize all configured GPIO pins as digital inputs.
• Enable the Raspberry Pi Pico's internal pull-up resistors.
• Scan all buttons periodically.
• Detect button press events.
• Detect button release events.
• Generate exactly one press event for each physical press.
• Generate exactly one release event for each physical release.

Assumptions

• Buttons are active-low.
• One side of every switch is connected to a GPIO pin.
• The opposite side is connected to ground.
• Internal pull-up resistors are enabled.
• buttons_scan() is called periodically from the main loop.