Reed switch encapsulated door sensor or window sensor magnetic MC-38 security contact alarm

encapsulated reed switch
with magnet
sold as a pair of switch + magnet
with mounting holes and double sided tape
good for detecting if a door /window is open or closed
also ok for proximity sensing
Arduino compatible
For Arduino Users:
– connect 1 wire to any digital pin
– connect the other pin to GND
– set the pinMode of the pin to INPUT_PULLUP e.g. pinMode(2,INPUT_PULLUP); inside setup();
– when the switch is open (no contact with magnet / door is open), then expect a HIGH reading from digitalRead(). Reading is LOW when the switch is closed (door closed/magnet is in proximity)