Auzze’s RAMPS board came with Sprinter firmware already installed, but unfortunately, I’m not able to use this as-is. The thermistor’s that came with the hot end were 200k thermistors, and the pre-installed firmware was set up for the standard 100k thermistors.

I asked Auzze the best way to go about this, and he suggested the following method:

1. Download the Arduino Software
2. Download the Sprinter firmware.
3. Make changes to the firmware’s configuration.h file, then upload.

Downloading and installing the Arduino software from arduino.cc was extremely easy, as was downloading the Sprinter firmware. Once I opened up the sprinter.pde file in Arduino, the screen looked like this:

The following settings in the sprinter configuration.h file had to be changed:


#define MOTHERBOARD 33 


#define THERMISTORHEATER 2
#define THERMISTORBED 2


float axis_steps_per_unit[] = {80, 80, 3200/1.25,700}; 


const int X_MAX_LENGTH = 170;
const int Y_MAX_LENGTH = 180;
const int Z_MAX_LENGTH = 110;

I was then ready to upload. The first time I tried to upload it didn’t work; didn’t recognise the board. I then realised that I need to specify the board to load onto. In the arduino software, I had to set the board to ‘ATMega1280’, and the USB port. However, there were no USB ports to choose from on the list.

The default ports that came with the software were only Bluetooth ports, so I had to run the other piece of software that came with the Arduino package (FTDIUSBSerialDriver). This added two extra USB port options to the software, which enabled the computer to connect up to the board.

Once this was done, the new firmware loaded quickly onto the board. Of course, I’ve got no way of testing it yet, so I’ll install Pronterface next. Thanks for the great after-sales support, Auzze!