Skip to content

Wiring

This page describes how the Arduino Nano on the control board connects to everything else.

Breadboard-view wiring diagram: Displaymodul and Lichtmodul on the left feeding into Fotomodul, which connects to the Steuermodul/Arduino; the pump and valve motors, rotary switch, and power jack on the right.

Master pin map

Function MCU pin Dir Connects to
Card reader bit 0 A0 in Fotomodul 7-pin (pin 3)
Card reader bit 1 A1 in Fotomodul 7-pin (pin 4)
Card reader bit 2 A2 in Fotomodul 7-pin (pin 5)
Card reader bit 3 A3 in Fotomodul 7-pin (pin 6)
Card reader bit 4 A4 in Fotomodul 7-pin (pin 7)
Pump (inflate) D6 out Steuermodul MA/MM → TIP120 → AIRPO pump
Valve (deflate) D7 out Steuermodul VA/VM → TIP120 → CEME solenoid
Display data (DS) D8 out Displaymodul pin 3 → 74HC595 serial data
Display latch (STCP) D9 out Displaymodul pin 4 → 74HC595 storage clock
Display clock (SHCP) D10 out Displaymodul pin 5 → 74HC595 shift clock
Buzzer D11 out Displaymodul pin 6 → piezo buzzer
RNG seed A5 — must stay unconnected (floating)

Leave A5 floating

A5 is deliberately not connected. The firmware reads its floating, noisy analog value to seed the random-number generator. Wiring it to anything would make the seed deterministic and hurt game randomness.

Power

A single 12 V / 3 A supply powers the whole device, entering through a switched DC socket:

  • 12 V rail → the pump and the valve (switched by the two TIP120 channels on the control board).
  • 5 V logic rail → derived on the Arduino; powers the Arduino itself and the display module (74HC595 + buzzer).
  • 3.3 V → the card reader's Fotomodul, for a stable analog reference on A0–A4.

Where the connectors live

All three modules meet on the control board:

  • Fotomodul 7-pin — 3.3 V, GND, and A0–A4 (see the card reader).
  • Displaymodul 6-pin — 5 V, GND, DS/STCP/SHCP, and buzzer (see the display).
  • 12 V input and the pump/valve output terminals (MA/MM, VA/VM).