Battery holder

Geiger Counter Kit

Geiger Counter Kit

Commercial Geiger counters can cost hundreds of dollars. Build your own at a fraction of the price! This easy-to-solder kit can be built in an evening and it works just like you think it would; clicking and blinking in the presence of radiation. Just follow the instructions here to build it and use it. Your […]

MonoBox Powered Speaker

MonoBox Powered Speaker

Learn how to build inexpensive powered speakers that amplify the output of your headphone music player. It may be small, but this speaker can still rock!

Optical Tremolo Box

Optical Tremolo Box

Plug your guitar into light-programmable waveforms with this unique effects box.

Tiny Wanderer

Tiny Wanderer

In early 2011 my robot club, the Dallas Personal Robotics Group, was looking for a way to help our beginning members build up their skills. To this end, we produced a series of lessons covering 5 topics needed to make a simple, programmable robot: making PCBs with the toner transfer method, programming ATtiny microprocessors, laying […]

Coffee Table MAME Console

Coffee Table MAME Console

By John Baichtal and Adam Wolf Do you remember those classic video game arcades filled with rattling quarters, 8-bit songs, and flashing lights? You can reclaim that excitement in your own living room with this Coffee Table MAME Console. In 1997, Italian software developer Nicola Salmoria released the first iteration of MAME (Multiple Arcade Machine […]

Wind-Triggered Lantern

Wind-Triggered Lantern

Create a little magic in your yard with this flickering garden lantern triggered by the wind, made with spare parts you probably have lying around your house.