Chris I've seen in a couple of places on the web that USB to Parallel adaptors don't work with modified web cams. See the snippet below as an example. I may need to join the QCUIAG forum to see what the discussion is there.
I am having a think about trying to use an Arduino card (
http://www.arduino.cc/) but have not worked my way throught the issues yet (such as getting camera software to use it). If thats viable I might also be able to use it for speed control for an EQPlatform I'm working on. I've not played with an arduino yet but the writeups I've seen on them suggest that they are very versatile.
I may end up having to do what is described below but I'm trying to look at options first in case there is a better way of doing this.
http://slscope.co.uk/astro_projects/...ackground.html
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USB to parallel adaptor are available, but DO NOT WORK with modified webcams. Also PCMCIA to parallel adaptors are not usable for this task. This topic has been discussed on the QCUIAG forum.
USB to serial adaptors are available and these can be used to control modified webcams via yet another adaptor. The down side is that serial ports provide only two lines which can be used for control purposes (ie RTS and DTR). This means that it's not possible to provide full functionality for an SC2 mod (see below) via a serial port. However, it is possible to control basic long exposure and amp-off operation via USB/serial operation. Refer to Steve Chambers circuit. This arrangement provides an interface between a serial port and a conventional SC1.5 or SC2 (again see below) modified webcam, but long exposure operation must be enabled/disabled via a manually operated switch.
So in the absence of a genuine parallel port, the procedure is to modify a webcam in the usual SC1.5 or SC2 (again see below) way, make up a serial to parallel webcam adaptor, fit a USB to serial converter to the computer, and then plug them all together."
Bob