>>521226194
At first I did a fume extractor for soldering, now thinking about a lamp for the same purpose. Later thinking about installing smart-home systems.

My very first project was an autonomous ( a week of scheduled work time ) ultrasonic dog deterioration device.
Basically I have a pack of aggressive stray dogs nearby living on the abandoned territory and the administration having hard times catching them.

The device went working, but what I didn't expected is that ultrasound without an actual physical object that threatens them doesn't scare them off from the territory, but makes them a bit nervous.
So after 3 days of working my device made the local pack immune to the ultra sound, they placed a dog-guard on watch near to it and kept on doing their casual stray dog things, including barking, bullying children etc.
The device was disassembled and my family equipped with pepper spray.