i got a more general Question. I designed my own shield for the Arduino Mega using the extra pin header ICSP header to provide SPI to multiple chips. I got the slave select pins 4, 10 ,48 (changed from 53 by wire). How do i set up the SPI? Which of the SPI channels is provided on the header and how do i define a specific slave select for it (or no slave select at all for bit bang SS Pin)?
Hello, I also have a question about the SPI bus. I use a sd card shield with the SdFat library. Everytime I set the SCK_Speed over 15 MHz the sd-card initialization doesn't work. Has anyone a clue why this bug appears and how I can fix it? Theoretically I think the SPI bus should go up to 40 MHz, shouldn't it?