complete personal project

chip8-handheld / build.log

Using the Chip8 emulator I'd already written, I built a retro-inspired handheld console: my first personal embedded project, and the first time I'd ever soldered or 3D-printed anything. I developed and tested it on a Raspberry Pi 5, then moved the final build over to a Raspberry Pi 3, hand-soldering a custom keypad PCB and an OLED display into a case I designed and 3D-printed myself.

hardware: Raspberry Pi 3 (final build), SSD1309 OLED (SPI), custom 4×4 keypad PCB, buzzer + status LED, 3D-printed case

software: Rust, hand-written SPI display driver, full Chip8 interpreter with quirks support

Planned to use an SSD1306 over I2C, but I2C was too slow for fast-updating game screens: switched to an SSD1309 over SPI, then had to write my own display driver from scratch since the crate I was using only supported I2C.
The Raspberry Pi 5 I developed on has a newer RP1 I/O controller that broke most standard GPIO libraries; ended up on rppal, one of the few that worked with it.
Learned to solder for this project: from the custom 4×4 keypad PCB to the rest of the wiring.
Runs my own game-selection ROM (written in Octo assembly) to switch between games without swapping files.

First working Chip8 handheld prototype — my first successful prototype

Internal wiring of the Chip8 handheld — the custom 4×4 keypad PCB and internal wiring, plus an ATXRaspi, PowerBoost 1000C, and a lithium-ion battery to turn the Pi on/off with a button press

Finished Chip8 handheld in its 3D-printed case — the finished device in its 3D-printed case: designed and printed for the first time ever

Another angle of the finished Chip8 handheld — another angle, showing the power button, game-switch button, status LED, and charging port

github