The device is the Dev-Kit for the Chipworkx Module. Card is always inserted. I took the code from the tutorial. I thought, that the most important thing is to mound the card. But for me it seems that the error occurs already in the constructor of PersistentStorage.
sorry, but I don’t understand what you mean.
I tried both - my own code (published in this thread) and the code from the sample on this website (downloads and tutorials). Both don’t work perfect, because the already mentioned error occures sometimes.
We also have this kind of problem. We are using a custom board based on EMX. For now we have produced 6 board based on the same schematic and same components. Boards can be power sourced by USB or through an external power supply (8-32V DC). We embedded on the boards linear regulators and traditionnal filtering and protection system to have a good quality of power source.
However 3 of the 6 boards can not works with Samsung 4GB SD cards. For them we need Sandisk µSD. The other boards works with Samsung but one of them do not work with a Sandisk… In our case sourcing with USB or a laboratory stabilized power supply do not impact this.