DC-DC High Power Adjustable Step-up Module 3.0~35V to 3.5~35V 100W with Digital Display Voltmeter

// Canonical beginner example for a DC-DC boost module with voltmeter
// Measures the module output voltage on A0 using the Arduino's 5V analog reference.

const int voltagePin = A0;

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ;
  }
  Serial.println("DC-DC boost module voltage monitor");
}

void loop() {
  int raw = analogRead(voltagePin);
  float voltage = raw * (5.0 / 1023.0);

  Serial.print("A0 raw = ");
  Serial.print(raw);
  Serial.print("  |  module output voltage = ");
  Serial.print(voltage, 2);
  Serial.println(" V");

  delay(1000);
}