ab 10.05.2018 in 29496 Kröte (Wendland)
As sensors, I have used an ultrasound detector and a camera used as a motion detector. The visitors were able to rake the gravel. The audible frequencies of the ultrasonic sensor I have used as audio input for the audio card of a Raspberry Pi - at the same time as a data stream for the Teensy 3.2 (modified firmware). As the 2nd sensor I used the camera data. Prynth 0.4 was used as the software for the Raspberry.