Although I'm able to use my RAMPS-FD, I wish there was a RAMPS/RADDS style board that was designed primarily to interface to breakout boards that handled the power (stepper or heater).
I'd really like to split it that way to make it easier to plug and play with different stepper controllers and ideally even the processor itself to optimize my printer.
For the breakout boards, I'd design them to connect with short 10-pin cables:
breakout type 1 - single stepper
ground, +5V, step, dir, enable, min limit, max limit, error
breakout type 2 - dual stepper
ground, +5V, step1, dir1, step2, dir2, enable, min1, min2
extruder breakout
ground, +5V, step, dir, enable, analog reference to breakout, thermistor value from breakout, error
bed breakout
ground, +5V, analog ref to breakout, thermistor value from breakout, error?
Then make all signals 5V and 5V tolerant, so you can switch breakouts across different processor boards (1.8V, 3.3V, 5V, etc).
This way high current or high voltage goes directly to the breakouts, and stays off the processor or printer interface board.
My thinking along these lines is influenced by the fact that I'm basically using my RAMPS-FD as a breakout board - I have no stepper controllers on it due to voltage limits.
I'd really like to split it that way to make it easier to plug and play with different stepper controllers and ideally even the processor itself to optimize my printer.
For the breakout boards, I'd design them to connect with short 10-pin cables:
breakout type 1 - single stepper
ground, +5V, step, dir, enable, min limit, max limit, error
breakout type 2 - dual stepper
ground, +5V, step1, dir1, step2, dir2, enable, min1, min2
extruder breakout
ground, +5V, step, dir, enable, analog reference to breakout, thermistor value from breakout, error
bed breakout
ground, +5V, analog ref to breakout, thermistor value from breakout, error?
Then make all signals 5V and 5V tolerant, so you can switch breakouts across different processor boards (1.8V, 3.3V, 5V, etc).
This way high current or high voltage goes directly to the breakouts, and stays off the processor or printer interface board.
My thinking along these lines is influenced by the fact that I'm basically using my RAMPS-FD as a breakout board - I have no stepper controllers on it due to voltage limits.