Таксофон
A 1969 Soviet payphone that answers to a Raspberry Pi
An AMT-69 payphone, the grey enamel box that stood on Soviet streets taking two-kopeck coins, rewired around a Raspberry Pi Zero W. Insert a coin, lift the handset, dial on the rotary dial, and the right number plays a sound.
The controller is a single Python file on lgpio, with no pigpio daemon. It reads three GPIO lines (the rotary pulse, the hook switch and the coin trigger) and drives playback through ALSA.
The interesting part was the dial. This one's number ring sits three pulse positions off relative to the pulse cam, so a correctly dialled digit arrives as three extra breaks. The controller subtracts the offset and, rather than coercing an out-of-range count into a plausible digit, logs it and ignores it. A wrong number is better than a confidently wrong one.
What it does
- Original rotary dial, hook switch and coin mechanism, all live
- Single-file Python controller on lgpio, no daemon
- Pulse-offset calibration measured over 18 labelled dials
- Out-of-range pulse counts logged, never guessed at
- OLED status display
- 3D-printed replacement coin mechanism
A closer look
