Wally Chang
Project · Shipped · April 2026

doorpi — a door that knows my face and waits for a peace sign.

Pi Zero + ESP32 + MediaPipe. A face-match unlock with a peace-sign verification step before the relay fires.

Solo build · running 24/7 on doorpihost
HardwareComputer VisionPython
REV v3unlock
Fig. 01 · system schematic · v3
camera → Pi → MediaPipe → ESP32 → 12V latch
Camera v21080p · 30fpsPi Zero W/dev/video0GPIO 18MediaPipehands · 0.6face_matchESP32J3:7UART · 115200Relay12V latchVcc ◯ GND ◯ GPIO 18 ▸ J3:7 ◯ 12V→relay coil

doorpi v3 shipped in April 2026. It is the third revision of a face-recognition + peace-sign door unlock that runs continuously on a small box behind a fixture in my apartment lobby. Pi Zero W on the capture side, ESP32 on the strike-plate side, the latch in the middle.

The peace sign is the part I am most proud of. It is the one-bit confirmation that the unlock was on purpose — the door does not open because my face happened to appear in the frame, only because I deliberately said it should.

Long-form writeup in progress — the real notes on the camera-driver fight, the auto-exposure rewrite, and the peace-sign stability gate land in a later revision.