SD card problems

Created Tue, 01 Oct 2013 05:30:07 +0000 by Ian Billing

Ian Billing

Tue, 01 Oct 2013 05:30:07 +0000

Can anyone please shed some light here for me?

I have a Max32 + wifi shield and am using the SD card. As long as I only read from the SD card all is well. But as soon as I have written to the SD card more than a few times it starts to fail and then fails completely. Taking the SD card out and reading it on my PC shows that it is perfectly okay - it is only in the SD card slot on the wifi shield that it fails. I have tried in 5 different wifi shields and am going through SD cards like potatoes - not cheap.

I reformat the SD cards Fat16 and Fat32 - no joy. Fine on a PC - fails to initialize in the wifi shield's SD slot! I am using SanDisk 4gb cards. I previously used Verbatim but too many of those failed to read right out of the box.

Can anybody help? Thanks.

Ian_B

Mon, 07 Oct 2013 20:22:42 +0000

I've been trying to reproduce your problem but no luck yet. If you are trying to use both the wifi module and the SD card there could be some bus contention since they share the SDI and SDO lines.

Do the wifi shields you are using have a MRF24WB0MA or a MRF24WG0MA wifi module on them? And are you just writing to the SD card using the MPIDE SD library functions?