Sure but you only need to bit-bang at 36 or so kHz while transmitting,
right? The receive side is a slow one as the receiver chip has an
integrated "demodulator".
If so then personally... I'd abandon the simple TX circuit, and use
a hardware ~36 kHz oscillator, gated by the serial output signal.
I don't think such transmitters are in thousands. Tens, maybe - the
cost of replacing/modifying them all should be insignificant. I guess
one could design and produce such a TXer in less than 20 minutes.
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Krzysztof Halasa
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