This code was developed on an Arduino Mega board using three 8825 stepper motors to control the MMU2 multi-color print head. It was designed to operate with the PRUSA mk3 printer. This code was developed to replace the stock MMU2 controller board, I got bored so I decided to create my own design. Getting it to play nicely with the mk3 was quite a challenge. This home brew MMU2 only will operate with the MK3 currently.
You will need an Arduino Mega 2560 processor board and a RAMPS 1.5 or RAMPS 1.6 shield (for the stepper motor controllers) - both are available on Amazon (see my BOM for additional details)
A serial cable is required (5 pin) in order to communicate between this board and the Mk3 controller. (Vcc, Tx, Rx, GND, Reset). Only 3 pins are required (Tx, Rx and Reset) in order to work properly with the Mk3.
This project is a work in progress and requires a knowledge of Mk3 hardware and software. If you don't know what you are doing, you can/will PERMANENTLY damage your hardware. I hope you have been appropriately warned.
you probably won't read this because it is too far down the page:
Stepper Motor controllers (8825) are high current devices and they get warm/hot. You can damage these controller easily (I have) if you don't adjust the source current. There is a very small variable resister you will have to adjust, I recommend setting this to 0.6V (details on how to adjust this are on the polulu.com website - look for 8825 stepper motor controller). If you don't have a multimeter for measuring voltage then STOP - you are in deep waters.
- Document Pinouts for each of the stepper motors
- Document Pinouts for 2 sensor cables
- Document Pinouts for Cable between MMU2 controller and MK3 controller (TX, RX, Reset, Vcc)