Project22.KY-035 Hall Sensor
=============================

Description
------------
This is a magnetic induction sensor. It can sense the magnetic materials within 
a detection range up to 3cm.
The detection range and the strength of magnetic field are proportional. The output 
is digital on/off.
This sensor uses the SFE Reed Switch - Magnetic Field Sensor.


Specification
--------------
- Sensing magnetic materials
- Detection range: up to 3cm
- Output: digital on/off
- Size: 30*20mm
- Weight: 3g


Connect
--------
.. image:: /img/connect/22_bb.png

Code
-----
.. code-block:: c

    int ledPin = 13;                // choose the pin for the LED
    int inputPin = 3;               // Connect sensor to input pin 3 
    int val = 0;                    // variable for reading the pin status
    
    void setup() {
    pinMode(ledPin, OUTPUT);      // declare LED as output
    pinMode(inputPin, INPUT);     // declare push button as input
    }
    
    void loop(){
    val = digitalRead(inputPin);  // read input value
    if (val == HIGH) {            // check if the input is HIGH
        digitalWrite(ledPin, LOW);  // turn LED OFF
    } else {
        digitalWrite(ledPin, HIGH); // turn LED ON
    }
    }


Phenomenon
-----------
.. image:: /img/phenomenon/22.jpg