11 hours ago
- The author built a physical 17x17 matrix of switches with integrated LEDs to simulate Conway's Game of Life, using a microcontroller (AVR128DA64) to control rows and columns.
- The LED display uses a multiplexing scheme where each row is active for 1/17th of the time, requiring higher current (150 mA per LED) to maintain brightness, with MOSFETs for row and column switching.
- User input is detected by reusing row select lines to ground and sensing switch closures via GPIO pins, with pull-up resistors integrated on the MCU.
- Speed control is analog via a potentiometer (0–10 Hz), and pressing a switch pauses game logic for two seconds to allow pattern drawing without speed adjustment.
- Firmware safety features include decoupling screen update from game logic (updating during a blackout window) and enabling a watchdog timer to reboot if the loop hangs.
- The switches are the most expensive component (~$3 each); alternative cheaper approaches exist but lack tactile feedback, and a more expensive electromechanical flip-dot version is also possible.
- Source code and PCB production files are provided for open-source replication.