Monthly Archives: September 2011

Improving range on the infrared channel

The range on the infrared channel, which I discussed in the last entry, is probably enough; but I’d like to increase it a bit.  With more range I can space modules farther apart if needed, and hopefully be able to have a wider angle between the transmitter and receiver.

Fortunately the signal output by the Darlington transistor pair on the receiver is a pretty clean digital signal.  At full power it ranges from (a little above) 0 V to (a little below) 3.3 V.  As the transmitter gets farther away the digital signal remains but the low voltage increases beyond the UART receiver’s ability to read a 0.  For example, at a large distance the UART signal might range from 2.5 V (logical 0) to 3.3 V (logical 1).

There are several options I’ve considered:

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