/*
* Relay Shield - Blink
* Turns on the relay for two seconds, then off for two seconds, repeatedly.
*
* Relay Shield transistor closes relay when D1 is HIGH
*/

const int relayPin = 22;
const long interval = 2000; // pause for two seconds
void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32! Relay Control");
  pinMode(relayPin, OUTPUT);
}
void loop() {
  digitalWrite(relayPin, HIGH); // turn on relay with voltage HIGH
  delay(interval); // pause
  digitalWrite(relayPin, LOW); // turn off relay with voltage LOW
  delay(interval);
}