Distance

JSN-SR04T Ultrasonic Sensor Module

Ultrasonic Module that can be used to measure distances from 30 centimeters up to to 3 meter. A bit more robust in moist or damp conditions.

HC-SR04 Distance sensor

Ultrasonic Module that can be used to measure distances from 2 centimeters up to to 5 meters.

Infrared distance sensor

Sharp GP2Y0A21YK0F GP2Y0A21 10~80cm Infrared Proximity Distance Sensor .