Want some information about the design of CompFlash GPS Rx

Johnson · Occasional Visitor Joined: Dec 03, 2004 Posts: 18

I would like to get some design information about Haicom HI-302, or other CF GPS Rx. For example, I would like to know what is used inside of the card for CF controller, FPGA/CPLD, or ASIC chip, or PIC/MCU?

Thanks.

Johnson

DavidW · Posted: Sat Dec 04, 2004 5:26 pm Post subject:

Most Haicom CompactFlash GPSes use an Oxford Semiconductors OX16CF950 UART - though I can't be sure about this model. The GPS chipset uses RS232 type serial, though, from memory, at TTL voltage levels (0V and 5V) - hence the use of a UART.

David

Johnson · Occasional Visitor Joined: Dec 03, 2004 Posts: 18

Thank you very much, David,

Could you please let me know if it is also used by Holux CF GPS Rx?

Do you know the approximate price of Oxford OXCF950? and its evaluation board? or any other High
performance single channel UART? We need about 10K per year.

Just the approximate price, so I can compare it with FPGA solutions.

Thanks.

Johnson

DavidW · Posted: Mon Dec 06, 2004 6:55 pm Post subject:

No idea personally, but I'm sure you can get more details from Oxford Semiconductor. The web page that mentions the OX16CF950 (which seems to be talked about as the OXCF950) is http://www.oxsemi.co.uk/pages/uarts/index.html

I don't know about the Holux - but many CompactFlash GPSes are similar in design. You may find out by downloading the Windows drivers for the CompactFlash GPSes what they use - whilst Pocket PC doesn't require any drivers, Windows does. In fact, I just downloaded the Holux GM-270 driver, and it's using an Oxford Semiconductors CompactFlash UART as well.

David

Johnson · Occasional Visitor Joined: Dec 03, 2004 Posts: 18

Hi, Dacid, thanks for the reply.

Do you know why Windows require a driver while WinCE/PocketPC does not?

Is there any standards or samples that I can follow to write the windows driver for my CF device?

Johnson

DavidW · Posted: Wed Dec 08, 2004 1:05 am Post subject:

On the whole, you obtain the driver from the UART manufacturer - not least as they can often supply you with WHQL certified drivers. That's one good reason to go for a UART rather than custom logic.

However, if you need to write your own drivers, you'll need to get yourself over to MSDN and start reading the stuff about the DDKs. The information on MSDN about Windows CE may explain why Pocket PC is happy to work with a CompactFlash UART without any additional drivers. I believe it's sometimes possible to use a CompactFlash UART on Windows by telling Windows to use a generic serial port driver - but Windows' Plug and Play will not do this automatically and it seems that companies like Oxford Semiconductor prefer to ship drivers that are optimised for their UART.

David

Johnson · Occasional Visitor Joined: Dec 03, 2004 Posts: 18

It sounds that I do not need to write my own driver for windows. That is good.

A friend told me that there is another CF-UART interface chip available: The mobilityIC™ Family from Socket Communication.
http://www.socketcom.com/embedded/asics.asp

but I did not find it was used by any CF GPS receiver yet.

As you said, the Holux and Haicom CF GPS adopted Oxford OX950 chipset. Do you know any other CF GPS Rxs (such as GlobalSat, I.TREK, and NAVMAN) also use this chip? Or do you know any other CF GPS Rxs use different chip? Before I made my decision, I want do a survey and see which is the best and most popular.

Thanks.

John

DavidW · Posted: Thu Dec 09, 2004 1:31 pm Post subject:

I'd get on with downloading the Windows drivers to see what people are using. The Oxford Semiconductor UART seems popular.

Socket stuff is usually very good (at least their consumer products are), if a little pricey. You'll have to contact Socket to see whether or not there's any Windows drivers - or whether my suggestion of using the standard Windows serial driver works with their UART.

David

Johnson · Occasional Visitor Joined: Dec 03, 2004 Posts: 18

Thanks, David,

After reading the fact sheets and application notes, I believe OX950 is the best candidate for CF GPS Receiver.

John

HOLUX UK Tech · Posted: Fri Dec 10, 2004 5:37 pm Post subject:

Hi John,

Maybe we can offer you some more detailed and focussed assistance. If you would be kind enough to inform us of what you would like to achieve we would be glad to assist you.

Best regards,

The HOLUX UK Technical Support Team.

Tel: 0870 321 5929 x 52
e-mail: tech@holux-uk.com
web: www.holux-uk.com

HOLUX navigation aids ".....Get there."

Johnson · Occasional Visitor Joined: Dec 03, 2004 Posts: 18

Great.

Could you please provide me any documents (either engineer document, schematics, hardware or software, or any others) about how the OX950 is used inside of Holux GM-270?

Any document will help. Please email me at gpsabove@yahoo.com

John

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