[Matt Meerian] introduced us to his kludge of cardboard, tape, mirrors, and electronics in the form of a clever non lethal robin trap. Whenever a pesky robin would enter the box, a sensor is triggered, the solenoid drops a lid, and the bird is contained (and we assume taken far away after that).
Of course the plan backfired; we wont spoil what happened, but you can click the link above to find out.
Related: Arduino Mouse Trap
Want to enter your hidden lair in style? Well [Jimmy] simply wanted to create a cool prop for his school’s homecoming dance. This project includes some obvious inspiration from Wayne Manor. [Jimmy] wired up the automated entrance with a 12VDC motor. In order for it to be able to push the door , the motor had to be attached to a gearbox, which directly powered a wheel. Current consumption issues were solved by using a wall-wart. Because a real bookshelf would still be too heavy, [Jimmy] dressed up a regular door with some patterned wallpaper to give it the right look. Coupled with a Shakespearean bust concealing the button, and some other cosmetic touches, this project was sure to impress any student who knew its secret.
[Tony Messina] had been fascinated with bat’s echolocation since he was a kid. After he retired, he decided to act on this fascination and built a simple bat detector.
The simple bat detector uses frequency division to lower the bat’s chirping to a frequency we can hear. For example, if a bat is calling at 91kHz the system will divide it by 16 and put out 5.7kHz. The system is digital, so all amplitude is lost. You’ll just hear clicks like a Geiger counter. Being digital has its advantages though. Unlike similar analog devices that have to be tuned to a small frequency range, the simple bat detector can detect a much wider window.
