HC-SR04 Ultrasonic Sensor with Arduino Tutorial (5 Examples)
Interfacing a Three Wire Ultrasonic Sensor to the PSOC 5LP - Development Boards, Kits, Programmers - Electronic Component and Engineering Solution Forum - TechForum │ Digi-Key
GitHub - SpulberGeorge/EasyUltrasonic: An Arduino library used to work with ultrasonic sensors in an easy way for measuring distance.