The SparkFun Ultrasonic Distance Sensor - TCT40 (sen-24805) a user-friendly upgrade to the popular HC-SR04 sensor, offers non-contact distance measurement from 2cm to 400cm with an accuracy of 3mm.

Off to the races? Formula One races, that is. This project by [mazur8888] uses an ESP32 to keep track of the sport, and display a “live” dashboard on a 2.9″ tri-color LCD.