UART transmission using IR photo diode

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MUKESH.K.S

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I am planning to try UART transmission using IR photodiode instead of TSOP. But the problem is that the photodiode is affected by sunlight. How can i solve these problems. Any body have tried this before ? I want your valuable suggections
 

Hi,
Any body have tried this before ?
Click to expand...

==> look for IRDA.


Klaus

- - - Updated - - -

Hi again,

in another thread you answer this:

==> The 38kHz modulation is especially made to solve the sunlight problem.

Klaus
 

Thank you for replying me. I am struggling with the bandpass filter design that I have to use with the IR diode. The tsop sensor itself contains the 38khz filter.
Whats the better method for it ?
 

Hi,

why bandpass?

* IRDA doesn´t need it. It is not modulated.
* TSOP1738 has built in filter
* Build your own receiver ciruit (does this make sense?) -->
you need to suppress DC caused by sunlight. Ok, indeed is about 0.0000116 Hz, with a lot of noise ;-)
and you need to pass 38kHz, but with low group delay to meet the baud rate.

all in all I think a receiver with built in filter (and AGC and demodulator) is reliable and cheap...
(At least I don´t want to design, calculate and test this all.)
Looking at Farnell gives 100 pieces of IR receiver with 38kHz filter. Starting below 0.50€ for a single piece

Klaus
 

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