WiFire SD card for logging?

[danielPatrick]

I have been trying to figure out if I can use the SD card slot in the WiFire for datalogging purposes. Looking through the reference manual, it seems as if it is read only, but it does not explicitly state this. Can anyone confirm if they have been able to get this working? 

Thank you!

-Daniel

[Larry Standage]

There is a SDReadWrite example sketch that is installed with the Digilent or chipKIT core. That will do writing and reading.

[danielPatrick]

Hey Larry. I have tried getting this code to work with the WiFire, but using multiple SD cards I have still not been able to generate a file. Is it possible that it is in a read only configuration? This quote from the WiFire reference manual makes me wonder if this is the case:

"The micro-SD card connector provides the ability to access data stored on micro-SD sized flash memory cards using
the SD card library provided as part of the Arduino IDE software system.
The SD card is accessed using an SPI interface on PIC32 microcontroller pins dedicated to this purpose. The Arduino
IDE SD library uses a “bit-banged” software SPI implementation to talk to SD card. However, software can be
written to access the SD card using SPI3.
On the Wi-FIRE board, SPI3 and I/O pins used to communicate with the SD card are dedicated to that function and
are not shared with other uses."

-Daniel

[Larry Standage]

If so, the card itself would be in the read-only mode.

How are the SD Cards formatted? I'm pretty sure the sketch can handle FAT16 and FAT32, but exFAT wouldn't be supported.

[danielPatrick]

I have them formatted as FAT32. For some reason, the 'SD.begin(10)' keeps returning false. On another forum I read that this can often be an issue with the speed that the microcontroller is trying to read from the SD card. Their solution was to modify the SD library to read at half speed. I have not tried this yet, but i am still digging around for other potential causes. 

I do have another datalogger that I can rely on, but one of the features of the WiFire that peaked my interest was the SD card reader. I would really like to get this working.

[James783]

I have successfully created a file and written data to an SD card using the WiFire. I used a SanDisk 32GB microSD card – refer to my previous question WiFire SD_ReadWrite. The example sketches should work.

Best Regards,

James