[Klaus] wanted some sort of aid for parking his car, and after running across a $4 ultrasonic sensor, decided to build his own speaking distance sensor (.de, Google Translation). Inside [Klaus]’ ...

It is likely that many of us will at some time have experimented with motion detectors. Our Arduinos, Raspberry Pis, Beaglebones or whatever will have been hooked up to ultrasonic or PIR boards which ...