serial to usb probs with the gps

[Birdseye]

my laptop has only usb ports, but the gps that I use for navigation has only a serial output. so I use a serial to usb cable and a driver from prolific technologies.

at first this worked ok but quirky. now it will not work at all and the laptop goes unstable ie the pointer starts jumping round the screen as if it was being driven by the gps position signal. the software is set up to use com 4 which is shown as unused in device manager

nothing much has changed to cause the probs except that I have loaded dsl software and the usual ms updates on to the laptop. system is xp.

can any body help?

<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.

 

[Mike21]

Would check if any updated drivers.
Tried this with a parallel to usb cable, sometimes worked, more often didn't. Appears to be way windows treats port as it effectively creates ( I think) a virtual port.
You may need to buy a port replicator, but might be worth speaking to GPS manufacturer to see what they suggest or to the notebook manufacturer.
Or worst case may need to get laptop with serial port/forums/images/icons/crazy.gif

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[Benbow]

this is a well know problem with some USB-serial adapters although I have not experienced it with mine. I understand that it is sensitive to whether or not it is plugged in before or after the machine is booted. If that fails, a new laptop would be an extreme solution ! a new USB-serial converter should do it.

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[Benbow]

I new I had seen it somewhere. Quote from pfranc.com:

PROBLEM:Sometimes Windows thinks a GPS (or other serial device) is a mouse! At startup, after Windows sets up the USB to COM port converter, it looks to see if a serial mouse attached to it and under some conditions thinks a GPS is a mouse! Two customers told me their laptop running XP thinks their Garmin GPS is a Ballpoint mouse! And then it won't let you use your new COM port! Not nice!
SOLUTION: Click: Control Panel, System, Hardware, Device Manager, Mice, Microsoft Serial Ball Point, Actions, disable, OK. Reboot. (this info thanks to Rick, via Ed Johnson via Joe and Jack\'s GPS web ).

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[Oldhand]

I think Benbow's answer will solve your problem. I use the Prolific converter with Windows 98, no problems at all.

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