GPS Receiver in 2.0 vs. 1.1 ports

Queenambeach · 03-05-2007, 11:09 AM

Will having the GPS receiver plugged into a 2.0 high speed USB port
over a 1.1 have any bearing on how fast it updates itself in
the software program?? In most of the OEM navigation systems, along
with some of the aftermarket ones (Kendwood, Pioneer, Eclipse) the
movement of one's position seems to have a continuous flow, versus
mines which has a more jerky forward movement. I know the sirf III
have a max refresh rate, but since I have 1.1 USB ports, I was wondering
if this could impact it also.

oh and by the way. I SEARCHED!!

kevinlekiller · 03-05-2007, 11:19 AM

I don't think it makes a difference. It gets changed to serial with software. And I think serial is 115kbps? and usb is like 480?

Curiosity · 03-05-2007, 11:52 AM

I believe they all use a 1.1 interface, so it doesn't make a difference.

Rob Withey · 03-05-2007, 12:01 PM

No difference. 1Hz NMEA doesn't even get close to the bandwidth available.

kevinlekiller · 03-05-2007, 12:13 PM

You can buy faster units, but they cost alot.

http://www.prairie.mb.ca/product/010-00321-07.php

http://www.semsons.com/evsaprgpsrec.html

Queenambeach · 03-05-2007, 02:52 PM

Quote: Originally Posted by kevinlekiller

You can buy faster units, but they cost alot.

http://www.prairie.mb.ca/product/010-00321-07.php

http://www.semsons.com/evsaprgpsrec.html

Okay, thanks for the link. I just got off the phone with Semsons and Sons Inc. because I almost bought the Evermore SA-320-5Hz GPS receiver. What customer support told me was that these receiver will work with our mapping software like (MS&T, Iguidance, Street Atlas, etc) but they wouldn't be able to take advantage of the 5Hz refresh rate because the program only allow a max rate of 1Hz. That sucks!!

Extide · 03-07-2007, 11:33 AM

No, the gps operates at 4800-9600 baud, that 4.8 to 9.6 kilobits per seond. A dialup modem is 56 kilobits per second for example and Usb 1.1 is 12 megabits (12,288 kilobits) per second. That means USB 1.1 has over one thousand times the required bandwidth. Usb 2.0 is 480 megabits.

Curiosity · 03-07-2007, 11:57 AM

There's a refresh rate hack for S&T but I don't know about the others.
http://www.mp3car.com/vbulletin/show...51&postcount=9

Queenambeach · 03-07-2007, 12:48 PM

Quote: Originally Posted by Curiosity

There's a refresh rate hack for S&T but I don't know about the others.
http://www.mp3car.com/vbulletin/show...51&postcount=9

But isn't this to help older version of S&T refresh quicker. Unless I'm wrong, this patch will refresh at 1Hz per second. I already have that. I'm trying to get the OEM type of refresh rate that will update my GPS position 5x per second.

MatrixPC · 03-07-2007, 04:56 PM

The only problem I see mixing USB 1.1 devices and 2.0 is the speed of 2.0 devices. Some cheap hub, it will make all USB 2.0 devices to run at USB 1.1 speed. So if you put gps receiver (1.1) to a usb 2.0 hub, make sure other device are also usb 1.1. So try to separate usb 1.1 into different hub than those usb2.0.
The 2nd problem is they may or may not wake up from hibernation.

Curiosity · 03-07-2007, 10:42 PM

Quote: Originally Posted by Queenambeach

But isn't this to help older version of S&T refresh quicker. Unless I'm wrong, this patch will refresh at 1Hz per second. I already have that. I'm trying to get the OEM type of refresh rate that will update my GPS position 5x per second.

D'Oh! Sorry, I didn't look at it that close, but still think it can be done. Most Windows apps use the standard timer which is set in milliseconds and is easily accessable with just a window handle. I just loaded up iGuidance and Spy++. There's one window with a 1000ms timer on it. It's the first child of the "iGuidance" window. I could just call SetTimer(hWnd, 1, 200, NULL) and it should refresh at 5Hz. That can probably be done with all of them.

Edit: It doesn't work with iG, if anyone is thinking of trying it. The timer has a process attached. It needs to be patched to work properly.