Connection problem between Ender-3Pro (Board V4.2.7) and Raspi (Octopi/OctoPrint)

[Stefan_W]

What is the problem?

Connection problem between Ender-3Pro (Board V4.2.7) and Raspi (Octopi/OctoPrint)

Hi,
I want to share my solution to the connection problem between Ender 3 (Creality-Board V4.2.7) and Octopi/OctoPrint.

After replacing my original board with the silent board (V4.2.7) I couldn't connect the printer to OctoPi.
Printing an object with gcode-file on sd-card was working.

Setup:

• Ender 3 pro
• Motherboard Creality V4.2.7
• CL-Touch
• Firmware: Ender-3 Pro- Marlin2.0.1 - V1.1.2 - BLTouch - TMC2225.bin
• Raspi with fresh installed OctoPrint image
• Std. USB cable (Micro-USB <-> USB A)

Printer plugged via usb to a raspberry with OctoPi.

My problem:

Connection between Octopi/OctoPrint and Ender 3 not working

Errors:

After booting Raspi, following errors occurs (access with putty):
dmesg | grep usb
...
[ 5.929392] usb 1-1.4: new full-speed USB device number 5 using dwc_otg
[ 6.059335] usb 1-1.4: device descriptor read/64, error -32
[ 6.279178] usb 1-1.4: device descriptor read/64, error -32
[ 6.499183] usb 1-1.4: new full-speed USB device number 6 using dwc_otg
[ 6.619248] usb 1-1.4: device descriptor read/64, error -32
[ 6.839187] usb 1-1.4: device descriptor read/64, error -32
[ 6.959382] usb 1-1-port4: attempt power cycle
[ 7.619265] usb 1-1.4: new full-speed USB device number 7 using dwc_otg
[ 8.081231] usb 1-1.4: device not accepting address 7, error -32
[ 8.199195] usb 1-1.4: new full-speed USB device number 8 using dwc_otg
[ 8.649177] usb 1-1.4: device not accepting address 8, error -32
[ 8.649422] usb 1-1-port4: unable to enumerate USB device
...

I also read a lot of posts and tried different Raspi's and cables. Connection does not work, same errors as before
I've connected also the printer to my Win-PC:

My solution:

I've removed the board from the printer (all cables and screws!).
Connect the board only with the USB cable to PC (should work) => ... tadaaa…

Win 10 Device Manager
New port is visible in Windows Device Manager:

• Port (COM&LPT)
  USB-Serial CH340 (COMxx)

=> Board (USB to serial chip CH340) is working

(Sorry, additional picture not possible, because this is my first post...)

Then I installed board step by step and check connection in between ...

-> No more problems detected

Also connection to OctoPi is working:
---> dmesg......
[ 6.199281] usb 1-1.4: new full-speed USB device number 5 using dwc_otg
[ 6.333615] usb 1-1.4: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64
[ 6.362004] usb 1-1.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[ 6.373233] usb 1-1.4: Product: USB Serial
[ 10.333471] usbcore: registered new interface driver usbserial_generic
[ 10.333604] usbserial: USB Serial support registered for generic
[ 10.375739] usbcore: registered new interface driver ch341
[ 10.375949] usbserial: USB Serial support registered for ch341-uart
[ 10.403438] usb 1-1.4: ch341-uart converter now attached to ttyUSB0

Important:
USB cable should be fully conntected (all 4 pins), not a power cable (+5V and ground pin only)

Also interesting:

Put tape on the 5V pin - Why and how

First of all this whole tutorial isn't a mandatory mod - you just need it if you run into issues (weird things are happening and you've already ruled out the more common suspects) or if the always running fan and illuminated display (even when the printer is turned off) disturbes you. I'm starting with the why part: If you connect a 3D printer via USB to your Raspberry Pi it can lead to all sorts of power related issues. Most of the time those issues occur only if you turn on your pi before …

In my case it was not a cable problem.

I hope this helps and I was able to help someone...