Crowtail- Magnetic Switch

Description¶

This is a Crowtail interface compatible Magnetic switch module. It is based on encapsulated dry reed switch MKA14103. MKA14103 is single-pole, single throw (SPST) type, having normally open ruthenium contacts. The sensor is a double-ended type and may be actuated with an electromagnet, a permanent magnet or a combination of both. The magnetic switch is a wonderful tool for designers who would like to turn a circuit on and off based on proximity.

Model: CT009320S

Features¶

• Crowtail compatible interface
• Minimum external parts
• 10W rating
• Rugged encapsulation

Application Ideas¶

• Proximity Sensor
• Security Alarm Sensor
• Level Sensor
• Flow Sensor
• Pulse Counter

Specification¶

Dimensions(mm):27.8(L)x20.0(W)x6.8(H)

Usage¶

With Arduino¶

1.The SIG pin of the module output LOW normally. When a magnet approaches the switch, the magnetic switch close and the SIG pin output HIGH. The following sketch demonstrates a simple application of using the Magnetic switch to control the led. When you put a magnet that has enough magnetic power close to the module, the switch is closed .Then the SIG pin out put a high voltage. You can use this to control the led. As the picture on the below indicates, the Magnetic switch is connected to digital port 2 of the Crowtail - Basic Shield and the LED is connected to digital port 5. When there is Magnetic approaches the switch, the SIG pin output a High voltage. Then the LED light. The hardware installation is as follows:

2.Copy and paste code below to a new Arduino sketch.

#define MAGNECTIC_SWITCH 2
#define LED 5//the on board LED of the Arduino or Seeeduino

void setup()
{
    pinsInit();
}

void loop() 
{
    if(isNearMagnet())//if the magnetic switch is near the magnet?
    {
        turnOnLED();
    }
    else
    {
        turnOffLED();
    }
}
void pinsInit()
{
    pinMode(MAGNECTIC_SWITCH, INPUT);
    pinMode(LED,OUTPUT);
}

/*If the magnetic switch is near the magnet, it will return ture, */
/*otherwise it will return false                                */
boolean isNearMagnet()
{
    int sensorValue = digitalRead(MAGNECTIC_SWITCH);
    if(sensorValue == HIGH)//if the sensor value is HIGH?
    {
        return true;//yes,return ture
    }
    else
    {
        return false;//no,return false
    }
}
void turnOnLED()
{
    digitalWrite(LED,HIGH);
}
void turnOffLED()
{
    digitalWrite(LED,LOW);
}

Then the LED light when there is Magnetic approaches the switch. Have a try!

Resources¶

• Crowtail- Magnetic Switch eagle file