Arduino KY-003 Hall magnetic sensor module

Arduino hall sensor

Buy this sensor at Amazon as part of 37 in 1 sensor kit

The KY-003 is a magnetic switch. If no magnetic field is present, the signal line of the sensor is HIGH (3.5 V). If a magnetic field is presented to the sensor, the signal line goes LOW, at the same time the LED on the sensor lights up. The polarity of the magnetic field is of influence to the switching action. The front side of the sensor needs the opposite polarity as the back of the sensor to switch on.

In the example program the led on the Arduino (pin 13) will be turned on when a magnetic field is present.

Connecting to the Arduino

  • Pin – = GND, connect to GND of the Arduino
  • Pin (middle pin) +5 v, connect to Arduino +5
  • Pin S signal, connect to Arduino pin 10
  • Power consumption, 3 mA in rest, 8 mA when switched on

Example code

KY-003 Hall magnetic switch

int Led = 13 ; // define LED Interface
int SENSOR = 10 ; // define the Hall magnetic sensor interface
int val ; // define numeric variables val</em>

void setup ()
  pinMode (Led, OUTPUT) ; // define LED as output interface
  pinMode (SENSOR, INPUT) ;  // define the Hall magnetic sensor line as input

void loop ()
  val = digitalRead (SENSOR) ; // read sensor line
  if (val == LOW) // when the Hall sensor detects a magnetic field, Arduino LED lights up
    digitalWrite (Led, HIGH);
    digitalWrite (Led, LOW);