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I have done it. Several things have to be done. The sun will produce a continuous current which has shot noise.
1. You have to minimize this by having an IR filter on the detector. Putting a tube around it to shade it from the sun helps. It further helps to have a lens in front to further narrow the response angle.
2. You then have to use a high frequency AC signal. 500 kHz in my case. This allows the receive amplifiers to have a very high low end cutoff to remove the shot noise which has a 1/f type spectrum in this case.
3. You have to design the transmission system to modulate the 500 kHz signal for your data. FSK is very good and use a PLL decoder. You can get continuous phase by having a vco in the transmitter or divide a higher frequency down by two integers and band pass filtering.
the distance you can reach depends on the transmitting power (one or more IR-LED's, current through the LED's) and the receiver sensitivity. Many years ago we built a communication system with a carrier frequency of 42kHz, using two TX LED's (SFH-type) with an opening angle of 18° and an integrated IR receiver. The maximum distance is about 15 meters indoor (no excessive sunlight) and about 4 meters outdoor with strong sunlight.
I have done it. Several things have to be done. The sun will produce a continuous current which has shot noise.
1. You have to minimize this by having an IR filter on the detector. Putting a tube around it to shade it from the sun helps. It further helps to have a lens in front to further narrow the response angle.
2. You then have to use a high frequency AC signal. 500 kHz in my case. This allows the receive amplifiers to have a very high low end cutoff to remove the shot noise which has a 1/f type spectrum in this case.
3. You have to design the transmission system to modulate the 500 kHz signal for your data. FSK is very good and use a PLL decoder. You can get continuous phase by having a vco in the transmitter or divide a higher
frequency down by two integers and band pass filtering.
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