=== Low cost 1.4km IR link === From:
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a low cost long range FSO link for telemetry purposes and combine it with the more expensive 10Meg
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Use a low cost TSOP1838 [[InfraRedLeds]]
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the the linux
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design for the receiving Rx side. Use a Jewelers Loupes 13cm lens for Rx and Tx as per Ronja 10Meg [[FreeSpaceOptics]]
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to extend the lirc.org design to 1.4km. For Tx use the HPWT-BD00 Lumiled as per [[RonjaChips]]
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[[TransimpedenceAmp]]
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For closer 100m distances use smaller plastic magnification lenses as per Kemo Kit nr.b213 #24-194
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This allows an extremely low cost , slow bitrate(115Kbit) long distance links for use on farms for example to switch valves and pumps, eliminating [[RadioModems]] for p-t-p links. Use clusters of [[RadioModems]]
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around either a low cost FSO 115Kbit or higher throughput 10Meg Ronja [[FreeSpaceOptics]]
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node and backhaul the RF signals to the base,depending on bandwidth requirements. The short range RF telemetry links sends out a signal on a PIR , IR beam trigger, indicating an intrusion.
=== Slow bit rate video transmission === Implement full motion video at 115Kbit with [[SerialCameras]](http:// bit.ly/12uGmP) over a 115Kbit FSO link. Vishay embedded IC does
115kbit. These low cost 115Kbit FSO links in turn interface with the more expensive Ronja 10Meg [[FreeSpaceOptics]]
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[[SerialCameras]]
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modules have inbuilt motion detection functionality. Combine these serial cameras with the low cost IR link and populate all over a large premise for surveillance purposes. The [[SerialCameras]]
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are CMOS based and 0.01Lux sensitive. Only CCD at present allows for
0.003lux. Note that there is no such thing as 0lux or
0.00000000....00lux , the CCTV sites claiming 0lux with [[InfraRedLeds]] on are incorrect.
=== IRDA specification === The [[IrDa]] protocol has to deal with LED flashover due to the very tight spacing between two adjacent leds used for Rx and Tx in a small embedded device. Flashover is solved by separating the the Tx and Rx parts with a pipe container.