audio via IR

dtec · Post by **dtec** » Fri Sep 17, 2004 7:39 am

Hi all,

I just signed up because I am looking for infomation on the transmission of audio via IR. (i.e. cordless headphones) I want to develop an IR headset (earphone/microphone) device and need to do some evaluation on whether or not IR would be the way to go. Any of you IR guru's comments/ideas/thoughts would be greatly appreciated.

Post by **The Robman** » Fri Sep 17, 2004 9:12 am

I doubt that it's possible because IR is a very inefficient way to send data. IRDA might be more feasible as this is the communication method used by some advanced PC gadgets to talk to the main computer.

Of course, the best method is probably RF, in other words you could transmit the data the same way a radio station does, just with a much shorter range. To do this legally though, you would need FCC approval.

dtec · Post by **dtec** » Fri Sep 17, 2004 9:22 am

Thanks, I was wondering too since this would be used outdoors, if daylight or bright sunlight would affect or diminish reception

pgk · Post by **pgk** » Fri Sep 17, 2004 9:31 am

I don't think the range on IRDA is that great (About a yard).

The typical data rate used for most of the remote control here is probably quite low, even irda in it's 1.0 form only went up to 115200 bps. Which wouldn't be enough to do a mid quality MP3 in realtime.

Being used outside you'd also probably be much more constrained to line of sight, since there are less things for the signal to bounce off of.

pgk · Post by **pgk** » Fri Sep 17, 2004 9:40 am

A quick google on IRDA found this article under the "practical experiences" heading they explain trying to increase the distance of 115kbps irda by using a narrower transmission (and therefore more tightly contained reception area) and could only reach 4 metres without adding additional optics (they were interested in communications between two fixed points, so the optics probably improved focus of the signal (narrowing further the reception area) which would not be that useful for a wireless headset)

dtec · Post by **dtec** » Fri Sep 17, 2004 10:00 am

Thanks, I just thought that since IR headphones were rather prevalent (my Sony TV has one built in) that it would be simpler than using RF and getting mixed up with the FCC