A teardown of piezoelectric buzzer from Electronupdate: An assembly commonly used on fire, burglar and similar alarm systems. Based around a piezoelectric disk coupled to a plastic cylinder with a hole on the end (used to amplify the sound). The controller appears to use a rom-based look up table to generate the sounds The pattern […]
Miceuz of wemakethings made this Chirp, a soil moisture level sensor based on ATTINY44. When the plant dries out, it starts to chirp reminding you to water the plant: Chirp is a plant watering alarm – as simple as that. You put it into the soil near a plant and it emits a tiny chirp when the […]
Spanner888 entered his Safer Alarm into the Open 7400 Logic Competition: This system provides a simple, effective and practical enhancement to existing alarm systems to tell you if your alarm has been triggered, tampered with, or lost power. Via the contact form.