How to Use KY-003 Hall Effect Sensor: Examples, Pinouts, and Specs

The KY-003 Hall Effect Sensor is a compact and versatile device designed to detect the presence of a magnetic field. It operates by utilizing the Hall effect principle, which generates a voltage when a magnetic field is applied perpendicular to the sensor's surface. The sensor outputs a digital signal, making it easy to interface with microcontrollers and other digital systems.

• Proximity sensing (e.g., detecting the presence of a magnet)
• Speed detection in rotating systems (e.g., motor speed monitoring)
• Position sensing in robotics and automation
• Magnetic field detection in security systems
• Contactless switches and encoders

The KY-003 Hall Effect Sensor module is built around the 3144E Hall Effect sensor and includes additional components for easy integration into electronic projects.

• Operating Voltage: 3.3V to 5V DC
• Output Type: Digital (High/Low)
• Output Voltage Levels:
  • High: VCC (when no magnetic field is detected)
  • Low: 0V (when a magnetic field is detected)
• Current Consumption: ~4mA
• Magnetic Polarity Sensitivity: Detects the South pole of a magnet
• Operating Temperature Range: -40°C to 85°C
• Dimensions: 18.5mm x 15mm x 7mm (approx.)

The KY-003 module has three pins for easy connection:

The KY-003 Hall Effect Sensor is straightforward to use in electronic circuits. Follow the steps below to integrate it into your project:

1. Power the Sensor:
   • Connect the VCC pin to a 3.3V or 5V power source.
   • Connect the GND pin to the ground of your circuit.
2. Read the Output Signal:
   • Connect the Signal pin to a digital input pin on your microcontroller or logic circuit.
   • When a magnetic field (South pole) is detected, the Signal pin will output a LOW signal (0V). Otherwise, it will output a HIGH signal (VCC).

• Magnet Orientation: The KY-003 is sensitive to the South pole of a magnet. Ensure the correct orientation of the magnet for proper detection.
• Debouncing: If the sensor is used in a high-speed application, consider implementing software or hardware debouncing to avoid false triggers.
• Power Supply: Use a stable power supply to ensure reliable operation. Avoid voltage fluctuations that could affect the sensor's performance.
• Distance Sensitivity: The detection range depends on the strength of the magnetic field. Stronger magnets can be detected from a greater distance.

Below is an example of how to use the KY-003 Hall Effect Sensor with an Arduino UNO to detect a magnetic field:

// KY-003 Hall Effect Sensor Example with Arduino UNO
// Connect KY-003 Signal pin to Arduino digital pin 2
// Connect KY-003 VCC pin to Arduino 5V
// Connect KY-003 GND pin to Arduino GND

const int hallSensorPin = 2; // Digital pin connected to KY-003 Signal pin
const int ledPin = 13;       // Built-in LED pin on Arduino

void setup() {
  pinMode(hallSensorPin, INPUT); // Set hallSensorPin as input
  pinMode(ledPin, OUTPUT);       // Set ledPin as output
  Serial.begin(9600);            // Initialize serial communication
}

void loop() {
  int sensorState = digitalRead(hallSensorPin); // Read the sensor state

  if (sensorState == LOW) {
    // Magnetic field detected
    digitalWrite(ledPin, HIGH); // Turn on LED
    Serial.println("Magnetic field detected!");
  } else {
    // No magnetic field detected
    digitalWrite(ledPin, LOW);  // Turn off LED
    Serial.println("No magnetic field detected.");
  }

  delay(100); // Small delay for stability
}

1. Sensor Not Detecting Magnetic Field:

   • Ensure the magnet's South pole is facing the sensor.
   • Verify the connections (VCC, GND, and Signal) are correct.
   • Check the power supply voltage (3.3V to 5V DC).

2. False Triggers or Unstable Output:

   • Use a stable power source to avoid voltage fluctuations.
   • Add a pull-up resistor to the Signal pin if necessary.
   • Implement software debouncing in your code.

3. No Output Signal:

   • Confirm the sensor is powered correctly.
   • Test the sensor with a strong magnet to ensure it is functional.

Q: Can the KY-003 detect both poles of a magnet?
A: No, the KY-003 is designed to detect only the South pole of a magnet.

Q: What is the maximum detection range of the KY-003?
A: The detection range depends on the strength of the magnetic field. Stronger magnets can be detected from a greater distance, typically up to a few centimeters.

Q: Can I use the KY-003 with a 3.3V microcontroller?
A: Yes, the KY-003 operates within a voltage range of 3.3V to 5V, making it compatible with 3.3V microcontrollers like the ESP32 or Raspberry Pi Pico.

Q: Is the KY-003 suitable for high-speed applications?
A: Yes, but you may need to implement debouncing techniques to ensure accurate readings in high-speed environments.