use an Arduino and a ultrasonic Module to measure distance and display it on a I2c 16x2 display
Ultrasonic distance measuring, output to LCD via i2c
Merged two scripts I found on the net.
Hardware used:
Arduino nano clone from banggood ID 940937
i2c 2x16 LCD from banggood ID 950726
Ultrasonic Module HC-SR04 from banggood ID 40313