Arnoud:
- ShiftOut does 1 byte in ca. 150us
then SPI does 1 byte in ca. 1us.
Wow, quite a difference. But in practice, just how much difference does it actually make?
What if the the Arduino needs to transfer 1KB? If that data is held in an array in ram, and a for() loop is performed to go thru each byte, what's the timing for shiftOut() vs SPI.transfer() for the 1024 bytes of data?