Can also get some guidance on this? If you run my code on a Mega with the above parameters (50) it works. If I run the same code on Zero it wont read the SD card. For a Zero what should I use?
if (!sd.begin(SD_CS_PIN, SD_SCK_HZ(F_CPU/4))) {
sd.initErrorHalt();
SerialUSB.println("unable to open sd");
}
Ive tried:SD_SCK_MHZ(50) and SD_SCK_HZ(F_CPU/3) also...