IR LED wavelength requirement

[nparikh]

Originally Posted by Kevin Watson

I suspect more can be gained by moving the carrier frequency away from the usual 38KHz to 56KHz. This would, of course, mean that you'd have to find a remote that used a 56KHz carrier, or invent your own. If you're really hard-core, you'd invent your own data protocol with a error detection (and possibly error correcting) wrapper to ensure you're getting good data. You might get some ideas by studying my 2004 beacon code and transmitter circuit. A perfect transmitter waveform generator would be a EDU or Vex robot controller. Of course, if enough folks are interested, I'd be willing to help out.

-Kevin

Good idea!

[lukevanoort]

We have actually switched our setup over to a 56KHz system. This year, we were lucky enough to have the help of two alumni who just got their degrees (Computer Science and Electrical Engineering), and without them we'd never have pulled it off. As I understand it, they switched the IR receiver on the IR board to a different model, and built a custom remote. I had nothing to do with it, so I don't know the details, but apparently it wasn't particularly hard. We never got it mounted before ship, but we should be able to see if such a change is actually useful next week.

[marccenter]

I switched over all the IR boards for the Chief Delphi team to use the 56 kHz Vishay TSOP IR part. This is just a matter of desoldering and removing the existing 3 pin piece and replacing it with the Vishay TSOP 34856. The units still work with the limited number of IR remotes tested (2) and still have jamming when both units are pressed at the same time. There is also a Vishay TSOP 7000 IR component that works at 455 kHz. My searching revealed that this is an uncommon remote frequency and I couldn't locate an inexpensive remote
that works at that frequency. I will post the Vishay TSOP 7000 IR pdf for reference.