MaxBotix High Performance Ultrasonic Range Finder - MB7360-200 HRXL-MaxSonar-WRC hub-sensoren Each phototransistor uses a capacitor

Each phototransistor uses a capacitor discharge circuit that allows a digital I/O line on a microcontroller to take an analog reading of reflected IR by measuring the discharge time of the capacitor

they are available with a 5 cm or 10 cm range and simply tell you if something is in their detection range

yet it provides much better performance than other IR alternatives

Pololu AVR C/C++ Library User

The I2CXL-MaxSonar-EZ sensors feature an I2C bus interface

MaxBotix High Performance Ultrasonic Range Finder - MB7360-200 HRXL-MaxSonar-WRC hub-sensoren Each phototransistor uses a capacitorThe weatherproof XL MaxSonar WRC is an outdoor ultrasonic rangefinder. This outdoor sensor offers very short to long range and a compact, rugged PVC housing. The ultrasonic sensor meets the IP67 water ingress standard and fits standard 3 4 inch PVC electrical pipe fittings. High acoustic output power combined with continuously variable gain, automatic real time background calibration, real time waveform signature analysis, and noise suppression