MPMD SKR 1.4 Overhaul Kit

thingiverse

Here is how I built my MPMD SKR 1.4 conversion. Included is everything I used including the firmware. **NOTE: THE FIRMWARE IS ONLY FOR THE SKR 1.4 AND NOT THE SKR 1.3! THERE IS A DIFFERENCE IN PINS!** **NOTE2: The print area is decreased about 5mm..I think...only way I could get the G33 Auto Calibration to work with the effector I used. If someone has other ideas or how to fix, lemme know!** This is actually pretty straightforward, I figure if you are researching this then you must have some idea of what you are doing, if not...I guess I can answer a question or two. But if all of this makes no sense to you....I suggest you stop reading now and go back to printing Benchys and Baby Yodas on your stock machine. Now that is out of the way, here is what I did: **FIRMWARE:** I edited the pins_BTT_SKR_V1_4.h file as I did not like having the pins spread across two files. So the ```#include "pins_BTT_SKR.h"``` is commented out and everything is in the pins_BTT_SKR_V1_4.h file. Edit it if you need to. Oh, this uses Marlin dev branch...so take that as you will. **WIRING:** Everything pretty much matches from the original MPMD board to the SKR 1.4. The only thing you actually need to tweak are the bed leveling wires. Just cut the ends off of each, match the colors and wire them together in parallel. After you'll connect it to the Probe connector on the new board. This is important since the SKR 1.4 only has 3 endstop connectors instead of the 6 on the 1.3. I have compensated for this in the firmware. **ENDSTOPS:** Use the Endstop Mount v1.stl to replace the optical endstops with some cheap mechanical endstops if you can't get the optical ones to work. I couldn't get them to work at all for who the hell knows why. You'll have to drill your own holes to mount the actual endstop to the adapter as these can vary from model to model. **BTT TFT24:** You have 2 options here. Modify the metal bracket that holds the original screen in place or use a different one. I used the same bracket and just modified it slightly. **RPi Serial Comms:** Communication between the SKR 1.4 and your Octoprint Pi without USB can be done by following this: - Connect TXD0 (pin 8) on the Raspberry Pi 3 or 4 to RX0 on the TFT header (pin 2) on the SKR 1.4. - Connect the RXD0 (pin 10) on the Raspberry Pi 3 or 4 to TX0 on the TFT header (pin 3) on the SKR 1.4. - Connect GND (RPi - Pin 6) to GND (SKR TFT header - Pin 5) on both. Now we have to enable all this junk on the RPi: - SSH into your Pi and enter ```sudo nano /boot/config.txt``` - Add ```dtoverlay=pi3-disable-bt``` to the end of the file and save it with CTRL-X and then Y. - Enter ```sudo nano /boot/cmdline.txt``` - Remove the string ```console=serial0, 115200``` and save it with CTRL-X and then Y. - Reboot your RPi - In Octoprint open Settings>Serial Connection and under Additional serial ports you'll need to add ```/dev/ttyAMA0``` - Magic. Ooo look...a diagram!  Erm...that's all I can think of right now....if I missed anything I'm sure someone will tell me. **Helpful links:** G33 Auto Calibration: https://www.youtube.com/watch?v=5G8GdNywsUQ BTT SKR 1.4 Github: https://github.com/bigtreetech/BIGTREETECH-SKR-V1.3/tree/master/BTT%20SKR%20V1.4 BTT TFT Firmware: https://github.com/bigtreetech/BIGTREETECH-TouchScreenFirmware