Coded IR Proximity Detector

摘要

The coded IR proximity detector is able to generate an electrical signal when the distance between the detector and a certain object becomes shorter than a preset value. The detector may be used as an automotive indicator and control. The detector consists of four parts: a controller, a transmitter, a receiver and the optical system, used both for transmission and reception. The transmitter contains a high-power laser diode driven by a recurrent sequence of position coded pulses. The receiver consists of a PIN photodiode amplifier module, a decoder and an output stage. The outgoing beam is separated from the incident (reflected) beam using a beam-splitter. A CMOS microcontroller comands the generation of the coded pulses, the reception and the decoding of the received pulses. The device features a very low power consumption due both to the pulsed regime and to the use of CMOS technology of the controller. A personalization through code for each detector is possible due to the use of the microcontroller, avoiding unauthorized or parasite commands from other similar devices in the neighborhood. The device's detection range is 10-15 m, enabling its use in military and robotics applications.