Logic Level Shifter 4-channel

// Canonical beginner example for a 4-channel logic level shifter
// Demonstrates shifting a digital signal between the Arduino Uno's 5V side (HV)
// and 3.3V side (LV) using one channel of the module.

const int hvPin = 2; // Connected to HV1
const int lvPin = 3; // Connected to LV1

void setup() {
  pinMode(hvPin, OUTPUT);
  pinMode(lvPin, INPUT);

  Serial.begin(9600);
  while (!Serial) {
    ;
  }

  Serial.println("Logic level shifter example started.");
  Serial.println("Press ENTER in the Serial Monitor to switch the signal.");

  // Start with the signal LOW.
  digitalWrite(hvPin, LOW);
}

void loop() {
  // Drive the 5V side HIGH, then read the translated 3.3V side.
  digitalWrite(hvPin, HIGH);
  delay(10);
  int lvReadingHigh = digitalRead(lvPin);
  Serial.print("HV1 driven HIGH, LV1 reads: ");
  Serial.println(lvReadingHigh);

  delay(1000);

  // Drive the 5V side LOW, then read the translated 3.3V side.
  digitalWrite(hvPin, LOW);
  delay(10);
  int lvReadingLow = digitalRead(lvPin);
  Serial.print("HV1 driven LOW, LV1 reads: ");
  Serial.println(lvReadingLow);

  delay(1000);
}