Interfacing Hall Effect Sensor With Arduino

Welcome to this beginner-friendly Arduino tutorial on the hall effect. By the end of the guide, you'll wire the module to an Arduino UNO, flash a short sketch, and read live values on the Serial Monitor — no prior electronics experience required.

What you'll learn

• How the module works in plain language
• The exact parts you need and how to wire them safely
• The full Arduino IDE sketch with comments
• Common issues and how to fix them

Arduino code

Open the Arduino IDE, paste the sketch below into a new file, install any libraries the sketch #includes (Tools → Manage Libraries), select your board and COM port, then click Upload.

int HallSensor = 2; // Hall sensor is connected to the D2 pin
int LED = 13; // built-in LED pin

void setup() {
  pinMode(HallSensor, INPUT); // Hall Effect Sensor pin INPUT
  pinMode(LED, OUTPUT); // LED Pin Output
}

void loop() {
  int sensorStatus = digitalRead(HallSensor); // Check the sensor status
  if (sensorStatus == 1) // Check if the pin high or not
  {
    // if the pin is high turn on the onboard Led
    digitalWrite(LED, HIGH); // LED on
  }
  else  {
    //else turn off the onboard LED
    digitalWrite(LED, LOW); // LED off
  }
}

How it works

The sketch initialises serial communication and the hall effect driver in setup(), then in loop() it samples the sensor at a regular interval and prints the result to the Serial Monitor at 9600 baud. Open the Serial Monitor (Ctrl+Shift+M) after upload to see live readings.

Troubleshooting checklist

• No readings: verify the baud rate in Serial Monitor matches the sketch (usually 9600).
• Garbage characters: wrong baud rate or loose GND wire.
• Library not found: install the exact library referenced in the #include line via Library Manager.
• Sensor not detected (I²C): run an I²C scanner sketch to confirm the address.

What to build next

Once the basic readout works, try logging values to an SD card, sending them over Wi-Fi with an ESP32, or pushing them to a Blynk IoT dashboard. Pair this module with our simulator round-up to prototype the circuit before soldering.