World's Smallest Bat Detector

Bonus bat fact: In a single midsummer night, the 15 million Mexican free-tailed bats from Bracken Cave in central Texas eat more than 140 tons of insects.That’s about the same weight as 20 elephants or one medium sized Blue Whale.

Disclaimer: the following is probably not practical but is definitely fun.

While experimenting with these bat detectors I tried to think of simple ways to display frequency; one of the main ways of identifying different kinds of bats. Since an oscilloscope is essentially a dot that scans across a screen at specific rates to display frequency and voltage, why not spin a bat detector to simulate the moving dot?

Feel free to make suggestions in the comments.

And a couple of photos. This should meet the rules of the Square Inch contest.

I will add a video of the spinning (!!!) version tomorrow.

I uploaded a test video of the bat detectors being tested with Robobat.

Also added some photos and description of the circuit with a frequency response simulation.

I've started detailing the design. I have some boards and parts and some are still on order. Time to tweak component values and add to the design description.

I will work on photos and videos soon.