Unusual Switch

For the project, I was walking around my room and looking for creative ways to create a switch. Finally, I found two American pennies which are made from zinc and are coated with copper, both of which are good conductive materials. Then, I realized I could make a switch that works when the coins touch. Wires are taped to the coins so that when the coins touch, the circuit closes and lights up the yellow LED. I connected the green and blue wires together to extend the reach of the coins. The idea is similar to Carrom – the coin that has an extended reach has to be flung into the other coin which will be relatively stationary. The setup can be seen below.

Next, I write some code for the Arduino, so that when they touch, the LED stays lit for 3 seconds so that the contact is captured and a hit or miss can be seen clearly.

void setup() {
  // put your setup code here, to run once:
  pinMode(9, OUTPUT);
  pinMode(A5, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int switchState = digitalRead(A5);

  if (switchState == HIGH){
    digitalWrite(9, HIGH);
    delay(3000);
  }
  else{
    digitalWrite(9, LOW);
  }
}