View Full Version : Wiring and install questions

Tim K
December 13th, 2004, 10:55 AM
I'd like to mount a USB-UIRT device inside the case of a tablet PC (hopefully I can fit it) and I am curious about possibilities for connecting it. I see in the picture on the USB-UIRT site that the attached USB cable is hardwired to the UIRT card itself.

Since I believe USB cables are really nothing more than 4 wires with different connectors on the ends, I'm wondering if it is possible to basically cut off most of the USB cable and "splice" the four wires from the UIRT into the internal wires of my computer's USB port rather than having to "Plug in" the UIRT device....can I do this??

Secondly, if all I do is "tap" into the internal wires of my PC's USB port (rather than cutting the connection altogether) do you think that I could still use the USB port for other devices as well?

Thirdly, and this may be more of a general IR transmitter question.....but are all IR transmitters (meaning the little diodes that actually send and receive the signals) the same? I guess I am curious as to whether I could disconnect the IRDA transmitters on my PC and connect them to the UIRT or if I should just try to mount the UIRT in that location to take advantage of the cutout and red plastic lens that is already in place.

December 17th, 2004, 07:19 PM
It all sounds feasable, except for trying to share the usb port. I imagine you would need to dedicate that port for this purpose. Just go one step at a time for troubleshooting purposes. Good luck. Perhaps post back with your results?

December 18th, 2004, 01:21 AM
If you ask really nicely, jon may be willing to put a header on for you ;)

As to whether or not it will fit... dunno, what tab pc do you have? (oaky, even then I won't "really" know, as I don't have one, but a pic would be great! Even a model # would satisy my curiousty)

Sharing the port.... Doubt it. Think IRQ. Even if you "tap" into it, it's consumed the resources. Not to keen on my USB protocal, so take that with a grain of salt.

As far as I have read.. yes! IR emitters are the same (edit: there are two different types: blinking and those that don't, and this can impact things (voltage draw?). Its the receiver that is different (please don't ask me to go into this, as I don't now the how and why)

I strongly recommend you ask jon himself about all this...
USB-UIRT Forums (

Especially about the IRDA to UIRT connect (I'm guessing no, but then again... what do I know)

Good Luck, and please keep us posted about this neat project!


Tim K
December 18th, 2004, 04:11 PM
I've asked Jon a bunch of questions already...and I don't even have a tablet PC yet. I'm trying to get a Fujitsu Stylistic 3400 or 3500 off of eBay.

According to Jon, it should be possible to "tap into" the USB port's internal wiring to install the UIRT. However, doing so would essentially disable the port because USB ports can only handle one connection at a time. Now, my proposed solution to this problem is to add an inline switch on the UIRT lines. In theory, if I move the switch to OFF, the UIRT would no longer be "connected" to the USB port thereby freeing it up for other devices. Jon seems to think this would work too. This would be sufficient for me as I would only need the UIRT connected while in my HT and I'd only need the USB port available when outside my HT. Having a switch would make this nice and clean.

Of course, this all assumes I can squeeze the UIRT into the case of a tablet!