Sonar is a great sensor to add to any small-scale robot project. And for a couple bucks, the ubiquitous HC-SR04 modules make it easy to do. If you’ve ever used these simple sonar units, ...

The HC-SR04 sonar modules are available for a mere pittance and, with some coaxing, can do a pretty decent job of helping your robot measure the distance to the nearest wall. But when sellers on ...