Simple Shed Alarm

thingiverse

Updated on 30th May 2013, this project was created to help a friend protect his shed/garage after the alarm he bought failed to function correctly. The alarm system consists of two circuits-one for PIRs and another for door switches. It is operated by a four-digit code for on/off functionality, and features both internal and external sounders/alarms. The Arduino-based system initially used a rubber keypad top, which required a custom PCB. However, the design allows for easy replacement with an off-the-shelf keypad. STL files for the case, as well as a SketchUp file and circuit diagram are included for convenience. The case has stand-offs that align with the holes in the PCBs, which were secured using M3x6mm self-tapping screws. The case bottom includes slots for wall mounting, but the holes for attaching the halves of the case together may need reaming out. The keypad connects to the six pads on the left side of the ATmega chip, and the instructions PDF covers wiring, connectors, and LED usage in detail. The project was shared as it might be useful to others or inspire similar projects.