GPS calculations with Stamp and um-FPU Coprocessor

Goos

I am trying to calculate the distance between to GPS receivers. Or better said between to GPS coordinates one of them is fixed and the other one is received from the Parallax GPS unit. To make the calculations I know I have to use the um-FPU coprocessor. I have down loaded the some sample programs from the Parallax and Micromega websites.

However I can not seem to get the wiring correct to have the GPS antenna send data to the uM-FPU and the uM-FPU to send it to the Stamp for it to display the data in a Debug screen.

I have attached the demo program I would like to get going before moving on to bigger things like above. Your help is appreciated.

Thanks Goos

Franklin

I'm not sure the uM-fpu should talk to the GPS but that both should talk to the stamp. Could you show us how you have things connected?

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- Stephen

cessnapilot

Hi Goos,

For the connection of the GPS and the FPU check the uM-FPU V3.1 Datasheet page 10.
- GPS should transmit with 4800 baud, native NMEA (not in smart) mode
- If GPS uses TTL levels, MAX232 can be omitted.

I do not have a Parallax GPS module but I suppose it works in NMEA mode, too. I connected 3 other types of GPS
to the FPU (and/or to te Propeller) without problems. So it should work.

If not, use a scope to verify lines, baud rate. Eliminate problem.

Or connect the GPS unit directly to the Stamp and run a demo program supplied by Parallax. To begin with...


- Istvan