Since the shield has a SD card onboard, it probably does not use the interrupt to read/write. At least I hope not. That would cause a potential SPI bus collision. That would result in corrupted data at best and hardware damage at worst.
Since the shield has a SD card onboard, it probably does not use the interrupt to read/write. At least I hope not. That would cause a potential SPI bus collision. That would result in corrupted data at best and hardware damage at worst.