Vinculum VDIP1 to a Garmin using the Propeller - Help?

dougec

I'm trying to communicate with a Garmin GPS using the Vinculum VDIP1.· Communication with the Garmin basically works by sending predefined packets of bytes to do such things as waypoint upload, position transfer, etc.

I'm using the propeller code posted by Mike Green (TestVinculum.spin) that bascially gives me a·terminal-like access to the VDIP1 using SPI.· This all works great - talking to the VDIP1 that is.· But as far as passing data to the Garmin to get reply packets from the Garmin, nothing ever works.· I want to basically send a "start session packet" composed of 12 bytes... But when I try to do this using the VDIP1's firmware commands, i.e.

DSD 12<cr>
000005000000

Then issuing a read of data with the DRD command.· I never get anything back from the Garmin.· I've also tried to set the VDIP1 to data mode by grounding the DATAACK and DATAREQ lines and sending the raw bytes programmatically, and then polling for any replies, with still no luck.

I can communicate great with the Garmin using a simple PC C program, but this also uses the Garmin USB driver for the PC.· Can anyone point me in the right direction so that I can get my VDIP1 to pass bytes between my prop and Garmin?

thanks,
-doug
·

Phil Pilgrim (PhiPi)

The fact that the Garmin requires its own USB driver suggests that interface through a Vinculum may not be possible. The Vinculum is designed to interface to certain standard device classes (e.g. USB flash memory). If the Garmin protocol doesn't fall under one of these classes, you will not be able to communicate with it via the Vinculum.

-Phil

Post Edited (Phil Pilgrim (PhiPi)) : 7/4/2007 3:47:25 AM GMT