Let's Make Robots!

Home-built sonar

Make had a posting about an article on LadyAdas ranting on a DIY sonar. You have to program in the functions normally taken care of in current modules, but it's a interesting start to building up a sonar sensor. I remembered another homebrew sonar from a while back, that seemed to work pretty well. As well as an old hack from certain Polaroid cameras (probably no longer findable).