[comp.sys.handhelds] hp48 remote control learning

peraino@gmuvax2.gmu.edu (Bob Peraino) (02/09/91)

     My naivete on the subject may be showing here, but it seems to me
that writing an IR learning program should be a fairly simple job for
someone who knows the hp48 internals. A tight assembler loop could just
digitally sample the IR receiver, for each key press of the remote
control. Each of these digital samples could be equated to hp48 keys,
and when pressed, those keys could regurgitate the digital sample
via the IR emitter with an equivalently timed transmitting loop, which
does what the receive loop did, in reverse, to a different address.
     To keep the sample sizes down, use a minimum sampling rate. What's
the old rule-of-thumb? Twice the maximum frequency? That's what it
was for sound, I believe. In this case, wouldn't the sample rate then
have to be twice the digital transmit rate, so as to get at least
two samples per bit?
     Of course, all of what I'm saying could be garbage, when it comes
to IR. If not, I hope it plants some seeds in someone's head who can
do something with it.

peraino@gmuvax.gmu.edu

johankha@tz.wimsey.bc.ca (e_mou) (02/18/91)

Doesn't that rule apply only for sampling from an analog waveform?
Presumably, if its digital you can easily check for accuracy during 
transmission.
Just my two bits.