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HP Forum Archive 16

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HP-41 IR module as remote control?
Message #1 Posted by Geir Isene on 6 Aug 2006, 9:57 p.m.

Is it possible to use the HP-41 with the IR module as a remote control for any devices exept the IR printers - like a TV set etc.?

      
Re: HP-41 IR module as remote control?
Message #2 Posted by Eric Smith on 6 Aug 2006, 11:23 p.m.,
in response to message #1 by Geir Isene

No. Only the 82440A/B printer or compatible devices.

      
Re: HP-41 IR module as remote control?
Message #3 Posted by Vieira, Luiz C. (Brazil) on 6 Aug 2006, 11:27 p.m.,
in response to message #1 by Geir Isene

Hi, Geir;

I guess that by using specific control routines (MCODE) one could mannage to have the IR module to send a set of characters that would normally not be sent with regular printing protocol. What I believe that cannot be changed are the signal characteristics, meaning the beam modulation waveforms. These waveforms can be observed at the Hewlett-Packard Journal, October 1987 issue, p. 18. I think that there is no way to change these characteristics. Somehow off-topic: based on the HP41 behavior after having an IR module connected to it, I believe it is more related to the HPIL structuire than to the original HP82143A peripheral printer.

The main issue, for me, is the distance range. I think that much of battery power is consumming when transmitting, and that might be the main reason the transmitting maximum distance is reduced to less than 18 inches, as stated in the 82242A IR Printer Module's manual.

Hope this helps. Not so good news, though... :(

Cheers.

Luiz (Brazil)

            
Re: HP-41 IR module as remote control?
Message #4 Posted by Eric Smith on 7 Aug 2006, 12:43 a.m.,
in response to message #3 by Vieira, Luiz C. (Brazil)

Quote:
I guess that by using specific control routines (MCODE) one could mannage to have the IR module to send a set of characters that would normally not be sent with regular printing protocol.

I don't think MCODE will let you send anything that you couldn't already send using synthetics, ATOX, or ACCHR.

Other than that, you're right. There is apparently a microcontroller inside the 82242A which accepts printer bytes from the 41 bus, and generates the IR modulation pattern. There's no obvious way to make it use any modulation scheme other than the Redeye protocol.

Quote:
Somehow off-topic: based on the HP41 behavior after having an IR module connected to it, I believe it is more related to the HPIL structuire than to the original HP82143A peripheral printer.

Based on a *very* limited look at some disassembled code from the module, I think you're right.

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