Inside [Klaus]’ device is an Arduino Uno, an HC-SR04 ultrasonic distance ... Right now, the voice is set up to speak the distance from an object to the sensor from 10 cm to 1 m in 5cm increments.

To supply targeting data for the launcher, an Arduino Uno uses an ultrasonic sensor pair mounted atop a servo. As the servo rotates, the returns from the ultrasonic sensor are plotted on a screen ...