Product DescriptionUse linear magnetic Holzer module and digital interface 13 with LED to build a simple circuit, making a magnetic field indicating light.Make use of the LED built in digital interface 13 to connect the linear Holzer magnetic sensor to digital interface 3. When linear magnetic Holzer sensor senses a button signal, the LED is on; otherwise, it will be off.Sample Code:Int Led=13; / / define LED interface Int buttonpin=3; / / define the interface of linear magnetic Holzer sensorInt Val; / / define digital variable valSetup void (){PinMode (Led, OUTPUT); / / LED was defined as the output interfacePinMode (buttonpin, INPUT); / / define linear magnetic Holzer sensor as output interface}Loop void (){Val=digitalRead (buttonpin); / / read the value of digital interface 3 and assign it to valIf (val==HIGH) / / when the linear magnetic Holzer sensor detect a signal, LED is flashing{DigitalWrite (Led, HIGH);}Else{DigitalWrite (Led, LOW);}