InfraRed Detector (PIC12F629)

Posted on Nov 26, 2012

This unit uses one TSAL6100 IR/LED emitter from Digi-Key. This IR diode has a narrow (10 degree) radiation pattern at 940 NM. It is driven via 2n2904 transistor for maximum current pulses. The detector is a Vishay TSOP4838 38Khz integrated receiver module. The 38Khz signal for the emitter is generated in software. Here is the idea: Send out a 38Khz IR signal and look for its reflection off a nearby object. Both the emitter and detector are optically and electrically isolated from each other to minimize self actuation. Additionally, the pulses are sent out only at certain intervals and the PIC only looks for the signal at the end of the output burst.

InfraRed Detector (PIC12F629)
Click here to download the full size of the above Circuit.

This device is demonstrably immune to most stray activation. It has a 25% greater range at night than in full sunlight. The entire unit is housed in a standard low-profile single outlet electrical box with a blank faceplate drilled out for the emitter and detector. The designation of this device is 'G1'. It responds to the following commands. /G1Pn - Set pulse count for IR transmission. /G1R - Read pulse count setting. /G1V - Return version number. The number of pulses generated on each 38Khz burst is adjustable. Setting the pulse count to 7 provides the minimum sensitivity and anything over 15 is the maximum. This unit automatically transmits code '/C1G1' over the network to the Clock/Console device (C1) indicating the detection of an object (by G1) within its range (8-10 feet). Note that the emitter and detector are optically isolated using heat shrink tubing.

Leave Comment

characters left:

New Circuits



Popular Circuits

12 Volt 20 Amp Solar Charge Controller
Audio Line preamp Driver
22 Watt Stereo Amplifier
Simple Audio Mixer Circuits
Several questions and countermeasures in the high-pressure frequency converter is employed
servo speed tester
car battery charger circuit
Symmetric Noise Source
Pulse Generator using Op-Amp
LM2005 20 watt amp electronic circuit design project
Handheld Oscilloscope Oscillator Circuit
ACU7505 chip MP3 player memory circuit
6 static display circuit
Structure and working principles of various protective circuit diagram e
EPSON PHOTO 830U printer power circuit