Re: Serial IR receiver problem

[nobody@xxxxxxxxxxxx (Dave Houston)]

Erk <mrman_man@xxxxxxx> wrote:

>Dave, I'm not to good with electronics, so I don't really know what
>you're aiming at with the oscilloscope approach. I guess it would be
>of interest to "see" the IR signal from the receiver... It sounds very
>cool though :-)

It's fairly simple and would definitely tell us whether the signal is being
corrupted. Connect a 100K resistor to your DCD line in the adapter with the
other end going to the TIP of a 3.5mm stereo cable. Put a 10K resistor
between TIP and GND (attach GND to your adapter GND also). You can then
record the signal as a .WAV file.

>That the problem should stem from a sharing problem of some resource
>like a hardware timer sounds very possible to me due to the "feel" of
>things. I'm not sure what a hardware timer is or what I should do to
>confirm that this is the problem though. I guess it comes down to how
>the skype and winlirc softwares are designed and therefore there is
>not much to do if you're right?

There's a timer chip on the motherboard and anything that needs to precisely
time intervals can call on it. I'm sure that's how WinLirc measures the
duration of the pulses and spaces from the IR receiver. If Skype also uses
the timer channels it might be interfering with WinLirc.

>One idea I have to solve this is to buy or build an USB based IR
>receiver hoping that the skype adapter won't affect it. I can't really
>assess the risk with this approach.

USB-UIRT is hard to beat. It does the decoding in hardware using its own
timers so it outputs the end result and there's no need to use the PC's
timer chip. If I'm guessing right about the timer, it should solve your
problem. There's a forum on their web page - you can ask whether others use
it successfully with the Skype device. I'm sure Girder can deal with its
output.

     http://www.usbuirt.com/