4-Channel Optoisolator Board

// 4-Channel Optoisolator Board example
// This sketch drives all four input channels on the optoisolator board.

const int ch1Pin = 2;
const int ch2Pin = 3;
const int ch3Pin = 4;
const int ch4Pin = 5;

void setup() {
  pinMode(ch1Pin, OUTPUT);
  pinMode(ch2Pin, OUTPUT);
  pinMode(ch3Pin, OUTPUT);
  pinMode(ch4Pin, OUTPUT);

  Serial.begin(9600);
  Serial.println("4-Channel Optoisolator Board demo started");
}

void loop() {
  digitalWrite(ch1Pin, HIGH);
  Serial.println("Channel 1 ON");
  delay(500);

  digitalWrite(ch2Pin, HIGH);
  Serial.println("Channel 2 ON");
  delay(500);

  digitalWrite(ch3Pin, HIGH);
  Serial.println("Channel 3 ON");
  delay(500);

  digitalWrite(ch4Pin, HIGH);
  Serial.println("Channel 4 ON");
  delay(500);

  digitalWrite(ch1Pin, LOW);
  Serial.println("Channel 1 OFF");
  delay(500);

  digitalWrite(ch2Pin, LOW);
  Serial.println("Channel 2 OFF");
  delay(500);

  digitalWrite(ch3Pin, LOW);
  Serial.println("Channel 3 OFF");
  delay(500);

  digitalWrite(ch4Pin, LOW);
  Serial.println("Channel 4 OFF");
  delay(1000);
}