I've been looking through the source, but it's extremely hard to follow with all the different architectures and ways of doing SPI in it. I'm trying to determine if the library defaults to 4MHz on the Zero, or if it runs at the maximum 12MHz, and if it is running at the slower speed, how to set it …

SDFat - What speed will be used on a Zero?

fat16lib August 29, 2016, 12:24am 4

There are no divisors in the latest SdFat-beta. Speed is set with SPISettings.

All SAM boards except Due use the standard library for all versions of SdFat.

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