When reed switch is opened, pin 2 of Arduino goes high with the help of the pull-up resistor R2, and the alert signal is available through the piezo-speaker PZ1 (not an active piezo-buzzer). At the ...

* the Arduino GND pin, and its anode to the 250 Ohm resistor. The * other pin of the resistor should be connected to the Arduino pin 8. * Connect the one wire from the reed switch to the Arduino 5V ...

The Reed Switch Module project demonstrates how to detect the presence of a magnetic field using a reed switch with an Arduino Mega. When a magnet is close to the reed switch, it closes the circuit, ...