I've got a USB GPS receiver that creates a virtual COM port in the OS. I have installed GPSDirect driver in order to create a Windows Location sensor out of it so that Microsoft Maps app would work. And it did work on my desktop. But now I've installed the computer and the GPS receiver into my car, and Maps never shows my location since.

So, I need to find out if it's a driver / location sensor problem, if I need to do something in Maps to make it work, or if the GPS signal is blocked by some internals of my car. Is there a program that could visualize low-level GPS data from the receiver via the Location Sensor API? If not, is there such a program that would work with a serial port GPS (if I uninstall the GPS Direct driver)?

  • Where is it installed "in the car". – Ramhound Apr 10 '16 at 6:13
  • @Ramhound: under the dashboard. Should be receiving straight through the windshield and the dashboard plastic. Or at least that's the idea. – Violet Giraffe Apr 10 '16 at 6:14
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    My best suggestion see if it works if you put it on the dashboard, the reciever might not be strong enough, If it doesn't have line of sight I know my Garnin "searches for satellites" if it out it on the floor of the car – Ramhound Apr 10 '16 at 6:19
  • @Ramhound: I would generally start by doing that, but I need to disassemble half the car to get to the receiver. Naturally, I'm not looking forward to it. Want to have a diagnosis before I start operating, you know. – Violet Giraffe Apr 10 '16 at 6:27
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    @Psycogeek: yep, I know. That's why it would be handy if I could actually see the data that the receiver is streaming. E. g. if it sees any satellites. Or if it actually does provide any data at all, for starters. – Violet Giraffe Apr 10 '16 at 7:17

Based on your description, I'd expect your GPS receiver to support NMEA protocol. To test it, you should install a terminal emulator (e.g. Putty), connect to the COM port created by your GPS and examine the data you're receiving. You may need to remove GPSDirect before (or use a laptop for testing).

In my experience, you should start receiving something right away, before any satellites are found (like $GPZDA strings with current time). Once the GPS finds enough satellites to provide a usable position data, it will start sending $GPGGA and $GPGLL strings. If you never see those, it usually means the signal is too weak. $GPGGA strings actually have a special field (#7, according to this document) which tells you how many satellites are in view.

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    I actually ended up using the free VisualGPS software (visualgps.net/#visualgps-content) for that, it's convenient enough and displays all you need for troubleshooting. – Violet Giraffe Sep 29 '16 at 8:30
  • Sorry for bumping the question then, I thought you were still looking for an answer. – Dmitry Grigoryev Sep 29 '16 at 8:34
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    Your answer actually does answer the question and contains some interesting technical information, there's no reason it shouldn't be accepted. – Violet Giraffe Sep 29 '16 at 8:40

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