Hello, I need to connect two boards to the same SD card. I have looked at the previous topics about that questions and always this configuration is really not recommended. However, I am forced to do this. I have already implemented a locking system between the two boards.
The idea would be to close everything related to SPI on a board, send an unlock to the other one and open the SPI connection. Obviously, this would be done bidirectionally, always having one board at a time able to write the SD. I cannot use a multiplexer, and I cannot transmit the data between the two boards and let one of them writing the SD.
I noticed that I should use the SdFat library as the SD has a problem with multiple begin().
Have you got any advice, something I am loosing in my design?