Introduction

The KY-024 Linear Hall Sensor is a magnetic field detection module based on the 49E analog Hall-effect sensor. It provides both analog and digital outputs proportional to magnetic field strength, making it ideal for position sensing, speed detection, and current measurement applications.

Key Features

Technical Specifications

Pin Configuration

Pin	Label	Description	Arduino Connection
1	GND	Ground	GND
2	+	Power (3.3V-5V)	5V
3	D0	Digital Output	D2 (Digital Input)
4	A0	Analog Output	A0 (Analog Input)

Wiring Diagram (Arduino)

// Basic Connections:
// GND → GND
// +   → 5V
// D0  → D2 (Digital Input)
// A0  → A0 (Analog Input)

// For magnetic sensing:
// - South pole increases output voltage
// - North pole decreases output voltage
// - No field ≈ VCC/2

Basic Magnetic Detection

const int analogPin = A0;
const int digitalPin = 2;

void setup() {
  Serial.begin(9600);
  pinMode(digitalPin, INPUT);
}

void loop() {
  int analogValue = analogRead(analogPin);
  int digitalValue = digitalRead(digitalPin);
  
  Serial.print("Analog: ");
  Serial.print(analogValue);
  Serial.print(" | Digital: ");
  Serial.println(digitalValue);
  
  delay(200);
}

Advanced Applications

// Convert analog reading to Gauss
float voltage = analogValue * (5.0 / 1023.0);
float zeroFieldVoltage = 2.5; // VCC/2
float sensitivity = 1.3; // mV/G

float gauss = (voltage - zeroFieldVoltage) * 1000 / sensitivity;
Serial.print(gauss); Serial.println(" Gauss");

// Measure RPM using magnet on rotating shaft
unsigned long lastPulse = 0;
float rpm = 0;

void loop() {
  if(digitalRead(digitalPin) == HIGH) {
    rpm = 60000 / (millis() - lastPulse);
    lastPulse = millis();
    Serial.print(rpm); Serial.println(" RPM");
  }
}

// Measure current via magnetic field
// Using split-core transformer principle
float current = gauss / 10.0; // 10G per amp
Serial.print(current); Serial.println(" A");

// Linear position via moving magnet
int position = map(analogValue, 0, 1023, 0, 100);
Serial.print("Position: "); 
Serial.print(position); 
Serial.println("%");

Troubleshooting