Automatic rain sensing wiper using IC 555, L293D & CD4017

Circuit Description:

1. IC 555 Timer (Astable Mode):
   • The 555 timer is configured in astable mode to generate a continuous square wave signal. The frequency of this signal determines the delay between wiper movements.
2. Rain Sensor Module:
   • The rain sensor module detects the presence of raindrops. When rain is detected, it triggers the circuit to activate the windshield wipers.
3. Transistor (Q1 – NPN):
   • The transistor acts as a switch controlled by the rain sensor module. When rain is detected, the transistor allows current to flow through the relay.
4. Relay:
   • The relay is used to switch the motor for the windshield wipers. When activated by the rain sensor, the relay turns on, allowing current to flow to the motor.
5. L293D Motor Driver:
   • The L293D motor driver controls the direction of the motor. It receives signals from the CD4017 counter to determine the wiper’s movement direction.
6. CD4017 Decade Counter/Divider:
   • The CD4017 counter divides the square wave signal from the 555 timer and produces output signals on its ten output pins (Q0 to Q9). These outputs are used to control the motor driver and hence the wiper movement