Newsgroup: comp.sys.palmtops

>From article <2ai773$2mh@zephyr.isi.edu>, by lpress@zephyr.isi.edu (Laurence I. Press):
>>>a PDA to control consumer electronic devices, and (2) using consumer
>>>electronic IR repeaters for PDA communications.  Has anyone tried
>>>any of these sorts of things?
> Does anyone have a description of or pointer to the TV/VCR control protocol?

There is no universal protocol.  Every manufacturer has their own.
Some manufacturers (e.g. Sony) have the same protocol for all their
appliances.  Most IR controls work by modulating a 40KHz IR signal.

If I remember correctly the Sony protocol has the command coded as a 16
bit number.  The first 4 bits are the device id, the other 12 the
command code.  One and zero are coded by having different ratios of
IR-on to IR-off.

One other protocol I decoded was used by a Hitachi stereo.  It
consisted of a 32 bit sequence which was the command code, followed by
its complement.

In both the Sony and the Hitachi cases, I was able to discover "new"
commands that were not available on the remote control, but were
supported by the appliance.  The Sony CD allowed three different modes
of forward and rewind; the Hitachi provided a radio station "zapping"
function, and a volume mute control.

Many IR car locks use a 32 bit, or a 24 bit code.

While we are at it, could a kind soul from HP post the IR port addresses
of the HP-100LX.  Using the HP-95LX data does not seem to do anything.
I will start working on a publicly available universal remote control for
the 100LX as soon as their are posted.  If they also post the System Manager
API specification and the EXM converter/libraries, it will also be
System Manager Compliant.

Diomidis
-- 
Diomidis Spinellis    Internet: <dds@doc.ic.ac.uk>  UUCP: ...!uknet!icdoc!dds
Department of Computing, Imperial College, London SW7     #include "/dev/tty"

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