Hi! I’m using the firmware interface for the SPI bus to communicate with an external slave. In stead of the traditional chip select, my setup utilizes a dual request/response system, so that both the Spark Core and the slave have an output pin where they can request and accept an SPI transfer.
I have mapped the Spark Core’s request line(output) to the SPI SS pin, but the controller seems to override my manual digitalWrite commands to this pin. I set the pinMode() after I run the SPI.begin(), but to no avail.
I used the exact same setup on both an Arduino Uno and Leonardo, where it worked fine. Could this be a problem with the SPI implementation in the firmware?