🚀 go-pugleaf

>>>>> On Wed, 2 Sep 1992 00:35:40 GMT, mancus@roger.jsc.nasa.gov (Keith Mancus) said:

>   We're in the process of building a small robot, and we'd like it
> to respond to a TV remote control.  Can anyone tell us:

>   (1) Is there a standard carrier frequency?  The IR sensor we're using
> detects 40 MHz.

    40 Khz is about right. It depends on the mfr, of course, but most
of the ones I've seen use 40KHz.

>   (2) Is the encoding scheme standardized?  If so, what is it?

    *No*...the best way to figure it out is to hook the output of your
sensor to a digital storage scope or logic analyzer. Set it to
trigger on the leading edge of the first pulse received & look at what
each button sends. I did it with a short assembly program and printed
out a 1/0 pattern on the console. 

>  
>   (3) Are there any other pitfalls we should know about?

    Make sure your robot doesn't respond to the guy in the next office
adjusting his cable box :-)

    See if you can get a hold of an IR phosphor test card (Radio Shack
#276-099 @ $5.95) to check the output of the remote. Real handy for
when you don't know if the remote's sending anything or the sensor's
broken.

    Pete



    

--
  Peter Simpson, KA1AXY       (508) 870-9837  fax: (508) 898-4212
  Data General Corp.  E236    pzs@ficus.webo.dg.com [128.221.228.82]
  Westboro, MA  01580         #include  <std_disclaimer.h>