I’m fairly new to embedded electronics so please keep that in mind when replying as I may not completely follow at first without my friend Google so any links you may have would surely be appreciated ;).
I was wrestling for a few hours today trying to get sample after sample and card after card working with my Uno and the Sparkfun uSD (DEV-09802) shield until I finally broke down and went to the configuration I wanted to use it in in the first place. This configuration is with the XBee shield stacked first followed by the uSD shield.
So the weirdness is that my uSD shield does not work at all stacked directly (with all the SPI speeds I selected) on the Uno but when stacked on top the XBee shield it works perfectly at SPI_FULL_SPEED and using the Arduino 1.0 SD library… I’ve now tried this with all three cards that were previously failing when stacked directly on top of the Uno. These cards are a 1GB (some generic brand), 2GB SanDisk and 16GB Samsung… Can anyone explain what could potentially be happening and why I seem to HAVE to have the XBee shield stacked as well as I may some day want to go with no XBee?
Any help would be appreciated but like I said… it works perfectly in the configuration I want for now.