Arduino fridge control

Fridge control:
with Arduino Pro Mini based, LM35 sensor, 2pcs 7segment display, shift registers, LEDs, momentary buttons, toggle switch, 1 Arduino compatible dou relay board.

Features:
- cooler on-off
- auto anti ice control
- defrost function

Normal operation:
Change cooler on and off temperature with buttons,
Each "off" cycle follows a short de-ice cycle.

Defrost function:
Switch on and a off : several long de-ice cycle. As it ends change normal operation.
Swicth on and left it on: no return to the normal operation, the cooler won't turn on.

The 7segment display show the measured temperature in Celsius. Below 0 shows Lo, above 10 shows Hi, while defrost, shows LE.