Hello Fernando,
The message asking me to insert SD card is appearing for me, and I have already researched several solutions, I have already tried several cards and in different formats, I have already checked all the welds on the board with a multimeter and they are all right, as well as trying the solutions presented in this one. link: https://ferduino.com/forum/viewtopic.php?f=8&t=104.
So I was not able to do the presented solution of changing the SPI_HALF_SPEED to SPI_FULL_SPEED or SPI_QUARTER_SPEED, I already tried to search with ctrl + F in the Ferduino code, but I did not find this command, I think this was taken from the code, am I right?
Rômulo Queiroz