Need to write my own USBwiz device driver for Garmin GPS 18

[Mikhail617]

I need to write my own USB driver (in C) for a Garmin GPS 18 device. I have Garmin's complete USB interface protocol documentation. I also found a Linux USB driver for the GPS 18 that somebody wrote. So it seems I have everything I need to get the job done but I've never done any USB development or write my own device driver before so when I sit down at my desk my head starts spinning as I don't know where to start. I am desperately in need of some methodology advice from somebody who has done this kind of task before! Can somebody please give me the first couple of steps to this process to get the ball rolling?

[GHI_Support]

First, see if Garmin works as a serial port on your PC. If it does, chances is that it works fine on USBwiz with our serial classes (Prolific, FTDI, Silabs, CDC).
If not, this might not be easy. you have to know somewhat about USB in general. Then use USBwiz raw USB commands to communicate with your device. You will understand these commands if you take a look at USB specs.

[Mikhail617]

Hello and thanks for response. The Garmin works on my PC when I assign a virtual COM port to it using Franson GpsGate 2.6 but I have not had any luck communicating to it via USBwiz with any of the serial classes at least using the 'Serial device test'. However, this might me due to the fact that 'Serial device test' only gives me three options for baudrate (2400, 9600, 115200) and the Garmin uses 4800. I should try modify the USBwiz firmware to include 4800 baudrate. Perhaps I will try that today.

On another note, I was able to connect to the GPS 18 using the RAW commands but so far no luck getting any data out of it but this is probably due to my inexperience with the USB protocol which I only started studying last week. Perhaps you can give me a sequence of RAW commands that I can use to start the communication based on Garmins commprotocol which can be found here http://www8.garmin.com/support/commProtocol.html

I will keep trying on my end to establish communication using either serial classes (with appropriate baudrate 4800) or RAW commands. I will update this post if/when I make any progress.

First, see if Garmin works as a serial port on your PC. If it does, chances is that it works fine on USBwiz with our serial classes (Prolific, FTDI, Silabs, CDC).
If not, this might not be easy. you have to know somewhat about USB in general. Then use USBwiz raw USB commands to communicate with your device. You will understand these commands if you take a look at USB specs.