If the Diamond Hotend version is on GitHub, it should be straight forward to see what they changed from the normal Marlin. And depending how much they changed, it shouldn't be too bad to cross those additions over to RC-8
Non of these pins are used on a ramps board. (well they go to aux-2, and aux-3) not used normally.
Looking further threw the code I see
* Enable this for SilentStepStick Trinamic TMC2130 SPI-configurable stepper drivers.
* To use TMC2130 drivers in SPI mode, you'll also need the TMC2130 Arduino library
* To use TMC2130 stepper drivers in SPI mode connect your SPI2130 pins to
* the hardware SPI interface on your board and define the required CS pins
* in your `pins_MYBOARD.h` file. (e.g., RAMPS 1.4 uses AUX3 pins `X_CS_PIN 53`, `Y_CS_PIN 49`, etc.).
So these pins are used for SPI-configurable stepper drivers.
Edited 1 time(s). Last edit at 01/14/2017 11:53PM by Dust.