Hi,
This is my first post at LQ so please pardon me if I am posting the wrong question in this group and point me to the correct location.

I have build a custom IR module which connects on Serial port, using off-the-shelf components and tested the same via terminal client and various receivers, the module seems to be working absolutely fine when I am transmitting the data between two computers, but when I try to record the TV-remote signal and transmit it back to the TV nothing works and I am not sure how to debug it.

I have tried to record data at various baud rate including B50 - B9600 - B38400 - B115200 and every thing else in between over /dev/ttyS0, and manage to capture the exact same data (data changes with baud rate) every time from remote (LG AKB72915207) I dump the data along with timing information into a file, and then I use the same data and transmit back to the TV which does not seem to be producing any effect, I have tried sending data from different distance and again it never seems to work, also I can see the LED lights glowing when I see through camera.

I capture the data by fopen - /dev/ttyS0 and set the baud rate, before I start read/write.
(my code is based on http://en.wikibooks.org/wiki/Serial_...g/Serial_Linux)

I have configured the LIRC on my system, I could not get the recording to work, but it is able to send the data from its remote database properly and TV seems to be reacting properly with my module+LIRC combination.

So the question.
- Is this a valid asumption that I can read TV remote data over serial port?
- Should I do the way LIRC does, replace the standard drivers and do the low level IO myself?
- How would you capture the TV IR remote data and transmit without using LIRC? (I am not looking for a C-program, though it would be great if I get one; just some hint from top of your mind).

Thanks all, even for reading.

Serial ports usually send and receive 8-bit data with start, stop and parity bits around it. But IR data is some 14-bit format or totally proprietary. How are you dealing with that?

http://en.wikipedia.org/wiki/RC-5

You might have better luck using the parallel port. Bring the data in on one bit and send data out on another. By clocking at 8X the bit rate or so and watching for the start bit, then sample in the middle of each subsequent bit and shift to get the received word.

1 members found this post helpful.

Thank you for your reply!

This is what I am trying to achieve, typically baud rate for TV remote is B9600 or lower, and when I capture the data at B115200 and play the same back at B115200, the output signal should be "in theory" same as the one send by remote and TV should react, it is possible there are some TV out there which might require additional dynamic information, but I have tested that the TV remote I am using is sending same "dumb" data every time.

I hope I was able to relate with your comments properly, please point if I am missing any thing.

Thanks.

Sounds good to me. If you know you are sampling at a much higher rate than the signal, you can also apply some digital filtering to square up the data. Removing 1- or 2-bit noise elements for example.
Sounds like a neat project!