SD card not recognized in expansion board with LoPy and deepsleep shield

[Robin]

I have inserted an 8GB FAT32 formatted SD card into an expansion board and put the deepsleep shield and LoPy on top of that. When i open REPL and do:

from machine import SD
sd = SD()

i get: "OSError: the requested operation failed"

Any clues to what is going on? The SD Card opens up fine in my Mac.

I have a sensor attached to pins G11 and G24 on the expansion board. Could this be conflicting on the Uart? The LoPy is on firmware 1.7.9.b1

[jmarcelino]

@robin
G11 is definitely connected to the SD card (SD_CMD) so you can't use it for other purposes if you need the SD card working.

[Robin]

Thanks @jmarcelino
The reference for the expansion board indeed lists this pin as being used by the SD card. Moved my sensor to G4 an G5. Its a pity G11 and G24 are the default Uart pins.

[Robin]

@jmarcelino does this mean you cannot use UART and the SD card?
I have not been able to use Uart 0 (this interfered with program and REPL execution) nor have i been able to redefine Uart 0 to different pins.

Is there an example of how to use UART and SD together?

[jmarcelino]

@robin
UART0 is a bit special - need to look into that myself - but you can easily redefine the UART1 pins (and UART2 unless on the GPy/FiPy)