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From: jmunkki@hila.hut.fi (Juri Munkki)
Newsgroups: comp.sys.handhelds
Subject: Re: HP IR-Remote Control
Keywords: IR REMOTE
Message-ID: <1991Apr20.130437.7783@santra.uucp>
Date: 20 Apr 91 13:04:37 GMT
References: <1516@lehi3b15.csee.Lehigh.EDU> <3372@charon.cwi.nl>
Sender: news@santra.uucp (Cnews - USENET news system)
Reply-To: jmunkki@hila.hut.fi (Juri Munkki)
Organization: Helsinki University of Technology, FINLAND
Lines: 23

In article <3372@charon.cwi.nl> jurjen@cwi.nl (Jurjen NE Bos) writes:
>jcohen@lehi3b15.csee.Lehigh.EDU (Josh Cohen [890918]) writes:
>>Jan, Falco, others, How can I directly control the IR led?  With this,
>
>That's the problem.  If we knew where the LED was, the remote control program
>would have been classic already...

I haven't hacked the HP48SX, but I just tried something that might be of
use to someone who wants to find out how to control the IR LED.

One problem with finding the LED control address is that you can't see
when the LED is on. Even though _you_ can't see it, any CCD video
camera will see it.  Point your HP to the camera and the IR LED will be
clearly visible as a bright white spot. All you have to do is try just
about every I/O memory location on the HP and watch a TV to find out if
you have succeeded.

Of course everything would be so much easier if HP spilled some information.

   ____________________________________________________________________________
  / Juri Munkki	    /  Helsinki University of Technology   /  Wind  / Project /
 / jmunkki@hut.fi  /  Computing Center Macintosh Support  /  Surf  /  STORM  /
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