From: David P. <dp...@dp...> - 2001-07-31 18:35:04
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Hi all, I'm trying to use lirc to transmit commands to my Sony AV receiver. I have had no troubles recording commands from my Sony RM-U305 remote control. irw reliably reports the correct button-presses. However, the receiver only responds to about 1 in 200 commands generated by lirc. I am using the "simple transmitter circuit" described on http://www.lirc.org/transmitters.html . My transmitter is about 6 inches from the IR receiver on the remote. My serial cable is about 3 feet long. It may be my imagination, but I think that when I hold the transmitter LED and move it slowly toward or away from the receiver, i get slightly better results. Perhaps a doppler effect? I suspect that this is a tolerance issue... lirc isn't transmitting the commands with enough time-domain accuracy for my receiver? Two questions: 1) Do you agree that this is likely to be the problem? 2) If so, what steps would you suggest to tighten the time-domain tolerances for lirc transmit? Thanks, dp |
From: Stephen D. <st...@da...> - 2001-07-31 19:42:11
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On Tue, 31 Jul 2001, David Potter wrote: > > Hi all, > > I'm trying to use lirc to transmit commands to my Sony AV receiver. > > I have had no troubles recording commands from my Sony RM-U305 remote > control. irw reliably reports the correct button-presses. However, the > receiver only responds to about 1 in 200 commands generated by lirc. > > I am using the "simple transmitter circuit" described on > http://www.lirc.org/transmitters.html . My transmitter is about 6 inches > from the IR receiver on the remote. My serial cable is about 3 feet long. > It may be my imagination, but I think that when I hold the transmitter LED > and move it slowly toward or away from the receiver, i get slightly better > results. Perhaps a doppler effect? > > I suspect that this is a tolerance issue... lirc isn't transmitting the > commands with enough time-domain accuracy for my receiver? > > Two questions: > > 1) Do you agree that this is likely to be the problem? > 2) If so, what steps would you suggest to tighten the time-domain > tolerances for lirc transmit? Hi, I had a similar problem to you - in controlling a Sky Digital receiver. Good news is that I've fixed it. I've just been doing extensive work on lirc_serial.o module - the transmitting part. The stock version does not produce a very faithful copy of the original waveform - there is a bug which makes pulse lengths too long, and the carrier frequencies aren't reproduced very accurately. For many devices this doesn't seem to matter, but my Sky box didn't want to know. My version uses the Pentium rdtsc instruction and times the waveform exactly by clock counts. I've measured the output waveform and its very very close to the original requested waveform. For non-Pentium boxes the code is also improved. I need to tidy up the patch, and will send it to Christoph (I did already send a previous version). But if you'd like to try it out in the meantime please let me know and I'll send it over. Regards, Steve Davies |
From: Stephen D. <st...@da...> - 2001-07-31 20:04:40
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On Tue, 31 Jul 2001, Stephen Davies wrote: > I need to tidy up the patch, and will send it to Christoph (I did > already send a previous version). But if you'd like to try it out in the > meantime please let me know and I'll send it over. Hmm - I see that my previous patch is in the current CVS. Are you running the CVS version or the last release? In any event I'm about to send Christoph the latest update. Your message was a good prompt. Steve |
From: David P. <dp...@dp...> - 2001-07-31 20:26:48
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> > > On Tue, 31 Jul 2001, Stephen Davies wrote: > > > I need to tidy up the patch, and will send it to Christoph (I did > > already send a previous version). But if you'd like to try it out in the > > meantime please let me know and I'll send it over. > > Hmm - I see that my previous patch is in the current CVS. > > Are you running the CVS version or the last release? I'm running a release version. I will pull down the CVS and try out your patch. Are there instructions anywhere? dp |
From: David P. <dp...@dp...> - 2001-07-31 20:57:36
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Just a quick note in reference to my earlier thread: I applied Stephen Davies patch and my transmit problems were instantly over. As Mr. Davies described, his modifications produce a more accurate signal, and my Sony STE-DE475 receiver suddenly started responding to lirc. Thank you very much, Mr. Davies. I appreciate your excellent work! dp |