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IR transmission

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You transmit an infared signal my modulating an infared light emitting diode. The modulation is entirely done in the digital domain.
 
hello
thanks for your response.
I am clear abt the followin things
* I will be transmittin IR at a frequency of 38 KHz to avoid interference wit visible light.
* Serial transfer of data by the PIC to the IR receiver on my robot
* calling of corresponding function for proper motion of stepper motor. in the specified direction
I need guidance for
* wat shd be the frequency of data transfer from IR transmitter?
*rough guidelines to implement the same
* advantages of IR transmission over RF transmission
Thanks
 
mayassn said:
* [What should] be the frequency of data transfer from IR transmitter?
If your frequency is 36kHz or 38kHz, you'll mostly likely transfer at about 560 bits per second. For Phillips devices, the 36kHz is sent was a square wave with period 27.8us (1/36,000 = 27.8u). To send a "0" for example, you transmit that square wave for 889us, then send nothing for 889us. The total time for that is 1/562nd of a second. IrDA allows higher speeds.

mayassn said:
Rough guidelines to implement the same
The "Consumer IR" guidelines apply. The LED wavelength should be between 870nm and 950nm. And there is a limited set of carrier frequencies that are acceptable. Encoding, data rate and other factors are undefined.

mayassn said:
advantages of IR transmission over RF transmission
Thanks
Low Power - Due to high LED efficiency and short range.
Low cost - The low frequencies require less design precision.
Small Circuitry - From lack on an antenna.
High Privacy - Difficult to eavesdrop beyond line-of-sight.
Few Regulations/Restrictions - Laws mostly limit light output.
 
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