Not able to connect or move

Mostly Printed CNC - MPCNC Troubleshooting
1

Hello all,

So I finally completed my build of the MPCNC Primo. It’s all wired and I was going to test it out. When I plugged it in it powered up. I tried to connect using My windows 11 pc with
Repetier host and it gave me error message Unhandled exception … The maximum baud rate for the device is 115200.

I thought that is might be the firmware since I had this sitting around for a few years before I could find the time to build, So I updated to the lates firmware for SKR pro v 1.2 for dual endstops. And I got the same error.

After a while of checking connections I was finally able to get some sort of jerky movement out of the drivers on both x and y, but it would start moving and I couldn’t stop it. I also got a "Low all message and a unknown command M221. I don’t know where to start to troubleshoot this, Any help would be appreciated.

IMG_5623
IMG_56231920×2560 486 KB

IMG_5624
IMG_56241920×2560 376 KB

Screenshot 2024-11-17 214310

2

Welcome.

There is firmware for the skr board and firmware for the tft screen. They are updated separately. Your screen doesn’t look how I’d expect so I think that at least needs updated.

Could you post the full file name of the firmware you downloaded to check it’s the right one?

The instructions and links for flashing both the skr and screen are here: SKR Pro - V1 Engineering Documentation

The screen also needs the black ribbon cable connected to work.

1 Like
3

I realized that after I posted. I did update the firmware on the tft screen and the boards to the latest versions. The fireware files were V1CNC Skrpro Dual 2209-2.1.1 and BIGTREE_TFT35.v3.e3.27.x.bin. The screen does look different now. I was able to move the gantries using the screen with the printer cables disconnected using only the black cable. But it was jerky and stuttered.

I get the same error when trying to connect with the computer and once the printer cables are installed I can no longer move using the screen

4

I don’t have that board, but I don’t think you are supposed to use the computer?

5

I figured it out, I was reading through some posts and came across one where Ryan had said when updating the firmware on tft35 include all files, I did that and it started working. I still have the “all low” message but I think I either have a bad cable or a bad driver on the Z axis, it seems to work intermittently. Is there a good test to determine if it is the driver. I can test the continuity on the wiring.

1 Like
6

With it powered off swap the driver to another socket - if the problem follows it’s more likely the driver. If it stays it’s more likely the wiring.

7

Oh like the common sense approach :slight_smile: Thanks For the help! Does the CNC really not connect to Repetier Host with the SKR pro?