Interfacing Linear Hall Sensor with Arduino

Linear Hall Sensor

A Linear Hall Sensor detects magnetic fields and produces an analog voltage proportional to the magnetic flux density. These sensors are widely used in contactless position sensing, current measurement, and speed detection.

Working Principle of Linear Hall Sensor

The Linear Hall Sensor operates based on the Hall Effect, where a voltage is generated perpendicular to both the magnetic field and the current passing through a conductor. This voltage is converted into an analog signal that varies linearly with the magnetic field strength.

Types of Hall Sensors

Digital Hall Sensor

  • Detects the presence of a magnetic field.
  • Outputs LOW or HIGH based on magnetic polarity.
  • Used in simple on/off magnetic detection.

Linear Hall Sensor

  • Reads changes in magnetic field intensity.
  • Generates analog voltage proportional to field strength.
  • Ideal for measuring position or distance.

Requirements

1. Arduino

2. Linear Hall Effect Sensor (e.g., A1302, ACS712)

3. Breadboard

4. Jumper wires

Pin Configuration of Linear Hall Sensor

Linear Hall Sensor Module

  • VCC: Connect to +5V on Arduino.
  • GND: Connect to GND on Arduino.
  • OUT: Connect to an analog input pin on Arduino (e.g., A0).

Wiring the Linear Hall Sensor to Arduino

To connect a Linear Hall Sensor to Arduino, wire VCC to 5V, GND to ground, and the OUT pin to an analog input like A0. This setup allows the Arduino to read voltage variations caused by magnetic fields.

Algorithm

  1. Initialize Components

    • Connect the VCC and GND pins of the sensor to +5V and GND on Arduino.
    • Connect the OUT pin to an analog input pin (e.g., A0).

  2. Write the Code

    • Define the analog pin in your Arduino sketch.
    • Use analogRead() in the loop to read the voltage from the sensor.
    • Optionally map the value to a specific range or condition.

  3. Monitor and Display Readings

    • Print the analog readings to the Serial Monitor.
    • Use the readings to control LEDs, motors, or triggers based on field strength.

  4. Test the Project

    • Upload the code to Arduino.
    • Move a magnet closer or farther from the sensor and observe changes in readings.
1// Define the pin connected to the analog output of the Hall sensor
2const int hallPin = A0;
3
4void setup() {
5  Serial.begin(9600); // Start serial communication
6}
7
8void loop() {
9  int sensorValue = analogRead(hallPin); // Read analog value from Hall sensor
10  float voltage = sensorValue * (5.0 / 1023.0); // Convert analog value to voltage
11
12  // Display the analog and voltage values
13  Serial.print("Analog Value: ");
14  Serial.print(sensorValue);
15  Serial.print(" | Voltage: ");
16  Serial.println(voltage);
17
18  delay(500); // Wait half a second before next reading
19}
20

Applications of Linear Hall Sensors

  • Contactless position sensing
  • Rotational speed measurement
  • Current sensing in power systems
  • Magnet-based proximity detection
  • Brushless DC motor control
  • Automotive throttle and pedal sensing

Conclusion

Interfacing a Linear Hall Sensor with Arduino enables precise and contactless magnetic field measurement. It's a great tool for building magnetic position detectors, motor controllers, and other automation systems.