Who wants to go outside to see if the mail has arrived? In the cold winter or rain I’d rather not have to put on a jacket and shoes, only to find that there was no mail. This project will notify you of the mail carrier’s visit, and as a secondary function it will remind you that the garage door has been left open. It can even be expanded to include other sensors
Step 1: Schematic
The project is based on the Atmega 168 chip. Since the design requires only minimal resources, most of the AVR chips would be acceptable substitutes. But having extra resources means adding functionality is easier than a redesign.
The device contains only a minimum number of parts (see schematic) .
The design has two sensors, the Garage door magnetic reed switch, and the Mailbox Light Dependent Resistor (LDR).