Gadget Freak

In their blog post, An Engineer in Wonderland, the anonymous 'Alice' commented on an ingenious piece of equipment that may provide inspiration for engineers everywhere.

Describing itself as "the world's biggest show and tell", the website instructables.com features a number of interesting DIY projects. One that caught my eye was 'LED floaties'

'Nak' writes: "My friend from blastwave labs gave me a call a couple days ago and he told me grand plans for the LEDs and batteries I had stagnating in my closet. His female counterpart was leaving her job at party city, so it was the perfect time to obtain a bunch of balloons (not steal) and rent a tank of helium."

Check out the video below. The theme music? Almost inevitably, Nena's 99 Red Balloons. But don't let that put you off!

Another related posting, by 'Tetranitrate', reads:

Photography enthusiast Nick Pagazani was hindered by the range and fixed location of his camera's flash.

Since his camera has no connector for an external flash, he needed a light-activated slave trigger to fire a remote strobe. It had to ignore the pre-flashes used for red-eye correction and fire only on the main flash.

His solution: Use a microcontroller to count pulses from a phototransistor and trigger the strobe at a switch-selectable count. Brighten up your shadowy background with this flashy accessory.

You can download the build instructions in this zip file.

This Gadget Freak originally appeared in Design News.

Circuit Description

For the microcontroller I decided to use the PIC12F629 for its small size and the fact that it has an internal oscillator to help reduce the part count. The main portion of the circuit is the sensing circuit.