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CaptureIR hardware

Posted: Sun Sep 17, 2006 5:57 am
by johnsfine
I'm trying to figure out why I can't build new CaptureIR hardware.

I have one working unit, that I built with an IR sensor Rob gave me long ago.

Rob, do you remember whether that was the QSE158 part Tommy recommended or some other?

I bought five QSE158 IR sensors from mouser.com and tried to build other CaptureIR cables following the documentation Tommy wrote. None of them have worked.

The Fairchild data sheet on the QSE158 is very unclear about which pin is which. On my first several tries, I followed the pin outs in the picture in Tommy's document (which I think is what I did for the first one that works). The most plausible interpretation of the pin out in the Fairchild doc is opposite to that. So I tried the opposite pin out and the part got very hot, so I disconnected it right away, but that one is probably fried.

Some of these tests were with solderless breadboard, so it isn't just my rotten soldering that is wrecking things.

I don't know what to even try next.

My one working unit has a poorly thought out physical design. But I don't want to risk breaking it by taking it apart.

Posted: Sun Sep 17, 2006 8:47 am
by johnsfine
I got something working.

I discovered the part Rob gave me was the QSE156.

It had worked poorly using power from the printer port. So I switched to 5v power from the USB.

Maybe that has damaged the pull up in my printer port (because the QSE156 has active high, not open collector).

Anyway a 10K pull up from the QSE158's output to 5V makes one of the two I just tested (probably the one I never connected backwards) work.

CaptureIR power

Posted: Fri Oct 31, 2008 7:55 am
by nuke12
John, I know this is an old thread but it does relate to the power issue.

I have a suggestion for CaptureIR. Currently you are pulling printer port #1 pin high to supply VCC. I agree that it is not the best power source. Why not pull two more pins high in CaptureIR and allow the hardware builder to "and" the leads with resistors to source the IR receiver VCC line.

This won't break any of the current builds and it should supply more power for people that want to use it. It also should get around using an external power source.

I think this is a good idea but maybe others can pipe up?