Is it possible to set the SPI to 2.500 kHz?
I read that it can be divided by 2,4, etc from 16MHz.
Can I use it like SPI_CLOCK_DIV6.4?
If not can someone get me on the right track?
No, you can't divide by 6.4
There are only a set number of divisors which can be found by looking at either the SPI.h file or the datasheet.
You won't be able to divide down to 2.5kHz from 16MHz. For something that slow you are best doing bit-banging.
Ty for the answer. I`ll look in to it.