Assert usb data pin

[enonod]

Is it possible to assert a USB data pin directly, for use as a control to something else please. It can be done with serial via the serial library but I cannot find a serial cable for PDA but have USB.

[taximania]

As soon as there is,
I'll be the first to let you know.

Unless someone knows different . . . . . .

[enonod]

I'll take that as a no then.

[cwtoyota]

Some PDAs have a serial interface that is not exposed to the user...

For instance, my Asus MyPal A639 has COM 1 which is a standard serial interface within it's sync connector, although Asus doesn't tell you about it. First I got a datasheet for the Texas Instruments IC that handles the Serial IO for the PDA. It showed that it uses TTL signals and voltage levels. I had to build a custom serial cable with the Asus connector on one end. Figuring out the pinout was a bit tricky, you need to write some software for the PDA to both send and receive data via the com ports. Then you have to use another device to submit data to the pins as well as check for output data. That's how I found which pins were TxD and RxD. Crude but effective.

Once you have the cable, the rest is simply handled by software... I used COM 1 as a normal port to connect to my optics.

If you happen to have an Asus A639 or other 6xx series, I can share my pinouts with you. Send me an e-mail and specify XLS or TXT format.

[enonod]

Thanks for your input. I have solved the issue a few weeks ago (posted 19 June I think)
I have an Acer 310 and was aware of the Com port, but didn't know the number because there are simulated ports, and that it was not physically exposed except on the connector.
I did exactly as you have described, wiring into the cable 26 minute pins which has a USB on the other end. I just brought out earth and RTS which worked fine. I just thought that USB would avoid any wiring.
I am using this new cable with a program I have written for Time lapse photography, triggering the SLR via wireless, from the Acer. Works very well.
There were two web sites showing the pinout, I believe I posted somewhere on this forum that one of them is totally wrong, possibly a Russian one. Beware anybody doing the same.

My cable of course now has a dangling USB connector. If your connector is 26 pin as on mobile phones I would be grateful to know where you got it to build your cable. I would much rather do as you have from scratch and perhaps put a full serial on the end.
Thanks for your offer of pinouts but I have them for mine.