Thread: Neo900 - finally a successor of N900
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joerg_rw is offline joerg_rw
2013-09-16 , 02:59
Posts: 2,222 | Thanked: 12,651 times | Joined on Mar 2010 @ SOL 3
#448
Originally Posted by Copernicus View Post
In any case, it might be best for now to just say that the Neo900 will have IrDA and CIR tx, and not worry about CIR rx until we know whether the IrDA hardware can actually handle it.
I'm rather sure and this is based on my experience as EE, that this will work. After all I'm designing the circuit ;-) IrDA RX is simply a photodiode and the signal it provides is directly connected to a GPIO of the "CPU" *). It's hard to find a story how this could possibly fail for learning CIR. BTW my TV does not have any special CIR chipset, just a receiver module that demodulates and filters the ~50kHz IR carrier. IrDA OTOH is not using a carrier, maybe that's why those statements above.


*) see http://fly.cc.fer.hr/~mozgic/UIR/ version-II, that's the standard CIR circuit nowadays (at least in my TV). SIR (IrDA, used in Neo900) works similar, just the RX doesn't demodulate, so for CIR RX the UART will see something roughly similar to 50kBd (~32..70) 101010101.... for the CIR sending a "1" aka mark, and simply no signal at all for CIR "sending" a "0" aka space.
/j
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Last edited by joerg_rw; 2013-09-16 at 03:37.
 

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