Vibration Alarm Designed to Last and Be Heard

YouTuber NonZero needed an loud alarm that would go off if it vibrates for over two minutes. While most of us would design something on a PCB and call it a day, he went the extra mile — several extra miles that is — and built a sensor as if it was going to be used in a tank.

This has apparently paid off, because after five months of 24/7 continuous use, it has worked flawlessly. As the explainer video shown below notes, he’s upgraded it from a perfboard construction to a professionally-made PCB as a sort of reward. He’s using an Arduino Nano for control in the final version, along with industrial-style LEDs to indicate the device is on and when it senses vibration. LEDs, along with a very large alarm, are actuated by MOSFETs, and vibration is detected via an AVXL335 accelerometer. A tilt switch provides the power on/off functionality.

The unit is fastened together with the help of a copious amount of hot glue, including on the wire connections themselves to provide strain relief. The power cabling is protected by a very rugged structure meant for use with a steam iron, and the unit is isolated from the warm surface that it monitors with four long spiky legs.

Be sure to check it out in the video below, or you can find code for the setup on GitHub.