// https://forum.arduino.cc/t/arduino-nano-serial-display-coding-help/1410954

int acval = 0, acvalold, actarget = 263;
int relayPin[] = {3, 4, 5, 6, 7};

void setup() {
  Serial.begin(115200);
  Serial.println("meaw");
  for (int i = 0; i < 5; i++) {
    pinMode(relayPin[i], OUTPUT);
    digitalWrite(relayPin[i], HIGH);
    delay(100);
  }
}

void loop() {
  acval = analogRead(A0); // read the value
  if (acval != acvalold) { // only update if acval updates
    acvalold = acval; // store old value
    Serial.print("ACval ");
    Serial.print(acval);
    if (acval < actarget) {
      Serial.print(" is less than ");
      Serial.print(actarget);
      Serial.println("V. Relays ON.");
      for (int i = 0; i < 5; i++) {
        digitalWrite(relayPin[i], HIGH); // relays ON
      }
    } else {
      Serial.println(". Relays OFF.");
      for (int i = 0; i < 5; i++) {
        digitalWrite(relayPin[i], LOW); // relays OFF
      }
    }
  }
}