SparkFun Forums

[dogcatcher]

hi all,

Has anyone managed to use the Sparkfun GPS and microSD shields together on a Duemilanove?

The plan is to make a GPS puzzle box, so ideally I'd like to store an array of co-ordinate pairs in a text file on the SD card, along with an trigger file for doing EEPROM resets (small array to hold found/not found state).

I've managed to use each shield separately using the Serial pins and the NMEA library to talk to the GPS module, and the fat16 library to talk to my 1GB microSD card, however when I try to use both in the same sketch the GPS module stops responding, or sometimes goes through the loop a few times before going to sleep.

As a total newbie to Arduino I'm afraid I'm trying to run before I can walk, and that there's some dark voodoo I need to learn first.

If you have successfully used both of these shields on a Duemilanove board and have an example sketch to share or any other hints and tips then that would be great.

I've got a funny feeling I need to read up about SPI master and slaves, but not convince that is the problem.

Thanks

Paul

[follower]

Has anyone managed to use the Sparkfun GPS and microSD shields together on a Duemilanove?

I've used GPS + MicroSD + WiFly shield together.

I've managed to use each shield separately using the Serial pins and the NMEA library to talk to the GPS module, and the fat16 library to talk to my 1GB microSD card, however when I try to use both in the same sketch the GPS module stops responding, or sometimes goes through the loop a few times before going to sleep.

It would probably be best to post your code somewhere to get useful suggestions. Do you have the GPS module/shield as the top-most shield? Are you running off USB or battery power? Are you checking the GPS frequently enough it's not losing data?

I've got a funny feeling I need to read up about SPI master and slaves, but not convince that is the problem.

Only the MicroSD shield uses SPI, the GPS shield doesn't use SPI so that shouldn't be your problem.

--Philip;