Is it possible to test new firmware on a $12 RAMPs board?  

Re: Is it possible to test new firmware on a $12 RAMPs board?

The short answer - no.

There are many differences between the two.

Re: Is it possible to test new firmware on a $12 RAMPs board?

i used a 12$ ramps 1.4 board for my printer and compiled the actual prusa 3.0.10 firmware for it.

but as richard.I already stated: there are a lot of differences. it' was really a pita to get the firmware compiled for the ramps, because you can not simply change the board type to RAMPS13 (as you usually do when compiling the marlin firmware). there is a lot of stuff inside the prusa code that prevents choosing another board (even the BigRambo doesn't work anymore) and you'll always run into errors if you try that.

so the only way i found to compile the firmware successful for the ramps is to change every single required/used pin inside the pins.h*.

furthermore, there are required circuits at the rambo-mini (like the rc-filters for the pwm generated control voltages for the stepper currents, or the driver transistor for the coldend-fan) which you don't have at the ramps. so you need to add these circuits...

*) before you ask: no, i don't provide my altered pins.h to anybody.

...If I buy a cheapo RAMPS board and temporarily replace the Rambo board would this work?
furthermore: if this would work, why should prusa assemble the much more expensive rambo-mini inside their printers, instead of a cheap ramps1.4, together with a mega 2560 ?

Re: Is it possible to test new firmware on a $12 RAMPs board?

I wanted to add more functionality to the MK2 but I don't want drop the money for a spare Rambo. I print every day so I don't want to have the printer off line for any period of time.

I have a bunch of Arduino boards that I can use so I think I will send tones to the speaker using gcode and a second arduino that listens to the gcode tones which do things like turn on RGB lights. This interface is one way from the rambo to the slave Arduinos. The RGB lights would let me know when the 1st layer is complete, or a color change is pending.

Anyways thanks for the input, it has been helpful for me while I am in the planning stage.

Re: Is it possible to test new firmware on a $12 RAMPs board?

@JeffJordan

Your custom MK2 is amazing. Any issues with the extruder that was printed with the hightemp PLAtec from BioFila?

Re: Is it possible to test new firmware on a $12 RAMPs board?

@JeffJordan

Your custom MK2 is amazing. Any issues with the extruder that was printed with the hightemp PLAtec from BioFila?

absolutely no problems, simply works as it should and holds its shape 100%.
even printed adalinda with a coldend-fan that was only about 50% running, that was before i noticed a problem with the previously used transistor to drive the fan -> no signs of degradation at the extruder body.

btw. the hotend of my custom MK2 even uses a 40W heater cartridge.