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Infrared remote control is possible with external hardware. All versions
after 06/02 can decode TTL-level IR data applied to LPT1 pin 10 (ACK-). Logic
level should be low on active IR and should follow the IR pulse patterns after
the 38 KHz carrier has been filtered out. There are numerous modules and ICs
available that perform this function. Here is a
PDF schematic of the self-powered
hardware I use on the scanner in my office.
Remote data can only be processed if connected to the first printer port
(pointed to by word at 408h), and the port must be connected to interrupt 7.
Some information given in the instructional text file may be contradictory.
That and the information below should be considered obsolete, as they only
apply to older versions of the program that could only accept remote data on a
serial port. All information regarding remote control codes, selection and
programming are still applicable. Also, the newer versions still support the
old method of receiving remote control data on a serial port.
The external hardware must detect the IR, convert it to 9600 bps async
serial and send it to the control computer. A
JPEG schematic
or
zipped OrCAD schematic files
(.SCH, .LIB and .PTL) show one possible IR to async converter,
which is known to work. Anyone serious about actually building
this thing will need the
source code
and a
6805 cross-assembler.
You will need to furnish your own programmer, however. Further
documentation about IR remote control, IRDA and perhaps a PIC version
with Radio Shack parts, instead of what was lying around here,
may be posted from time to time. Right now,
documentation
of the IR remote system is all there is.
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