SPI Slave Mode on Arduino Due

Official Hardware Mega Due
1

From examples like this Gammon Forum : Electronics : Microprocessors : SPI - Serial Peripheral Interface - for Arduino, I set up a basic communication to test simple SPI functionality between 2 identical Flip n Click boards that are recognized by Arduino IDE as a Due model. However, when compiling, the following error message shows up:

error: 'SPDR' was not declared in this scope

on the lines based of the code in the link:

// turn on SPI in slave mode
SPCR |= bit (SPE);
...
byte c = SPDR; // grab byte from SPI Data Register

From looking at other links, it appears that this type of slave mode declaration is not supported on Arduino Due. Has anyone ever implemented slave mode on Due or seen any links that would be helpful?

Any other general tips about maybe pinout mistakes, setup, or compatibility issues would be much appreciated.

Thanks

2

I haven't used slave mode on the Due, but any code that directly uses AVR registers will not compile for an ARM chip.

The SAM chip on the Due is capable of slave mode, but off the top of my head I can't remember the details as I've not looked at that chip for ages.

3

Ok that would seem to make sense. Do you recall seeing any examples that you could possibly link me to? Or point me to where I can find possible resources. It's a simple problem and in theory seems very easy.