#define RELAYSWITCHPIN 3 int delay1 = 10000; void setup() { // Set relay input pin for output pinMode(RELAYSWITCHPIN, OUTPUT); } void loop() { // Write a LOW to the relay switch pin // that is, turn the relay on digitalWrite(RELAYSWITCHPIN, LOW); delay(delay1); // Write a HIGH to the relay switch pin // that is, turn the relay off digitalWrite(RELAYSWITCHPIN, HIGH); delay(delay1); }