This Hall Effect Magnetic sensor detects the strength of a magnetic field. It can be used to build a simple circuit that flashes an LED when a magnet is detected.

Test Code

int Led = 13; // define LED Interface
int SENSOR = 3; // define the Hall magnetic sensor interface
int val; // define numeric variables val

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

void loop () {
val = digitalRead(SENSOR); // read digital interface is assigned a value of 3 val

// When the shock sensor detects a signal, LED lights
if (val == HIGH) {
digitalWrite(Led, HIGH);
}
else {
digitalWrite(Led, LOW);
}
}