Case study of an automatic car wash controlled by one Industrial Shields M-Duino 19R, the relay version of the Arduino Mega based M-Duino family. A load cell (or an infrared sensor) detects the car, the PLC starts the conveyor and three timers run soaping, washing and drying through four relay outputs: soap dosing pump, three brush motors, water pump and drying fan. A limit switch closes the cycle and manual ON and OFF buttons let the operator start or stop the system.

The PDF covers the challenge, the wash sequence, the system architecture with the full signal list and the hardware used. Interactive version: car wash case study online.