MK4 - Octoprint cannot connect  

RE: MK4 - Octoprint cannot connect

This screenshot shows the connection parameters of my MK4 in OctoPrint. For the rest of the configuration I reused the profile from my MK3.

RE: MK4 - Octoprint cannot connect

I tried AUTO and manual settings but cannot connect. This Octoprint RPi connects to my MK3 in a second.

Still thinking I might need a setting on the MK4 to enable USB-C for Octoprint use.

RE: MK4 - Octoprint cannot connect

Can you post the contents of your /boot/cmdline.txt and /boot/config.txt on the Pi?

RE: MK4 - Octoprint cannot connect

Also you could ssh into your pi and execute "sudo dmesg | grep serial"

This is the output on mine:

pi@octopi-mk4:~ $ sudo dmesg | grep serial
[    1.741351] uart-pl011 fe201000.serial: there is not valid maps for state default
[    1.741829] uart-pl011 fe201000.serial: cts_event_workaround enabled
[    1.741949] fe201000.serial: ttyAMA0 at MMIO 0xfe201000 (irq = 51, base_baud = 0) is a PL011 rev2
[    8.165478] uart-pl011 fe201000.serial: no DMA platform data

The correct value for the printer's serial port is "ttyAMA0" for me. I am on this version of octopi: "OctoPrint 1.10.1Python 3.9.2OctoPi* 1.0.0cam (build 2023.10.09.154319)"
If you are using an older image of octopi, the value for the serial port could be different, they changed something in the newer PiOS. But the output from dmesg should give you the correct value for the serial port.

RE:

Here are he contents.

/boot/cmdline.txt
console=serial0,115200 console=tty1 root=PARTUUID=f12f8521-02 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait

I left out a range of commented-out lines:

/boot/config.txt
# Enable audio (loads snd_bcm2835)
dtparam=audio=on

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
dtoverlay=vc4-fkms-v3d
max_framebuffers=2

[all]
#dtoverlay=vc4-fkms-v3d
# enable raspicam
start_x=1
gpu_mem=128

dtoverlay=hyperpixel4
overscan_left=0
overscan_right=0
overscan_top=0
overscan_bottom=0
enable_dpi_lcd=1
display_default_lcd=1
display_rotate=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x7f216
hdmi_timings=480 0 10 16 59 800 0 15 113 15 0 0 0 60 0 32000000 6

[    2.661577] uart-pl011 3f201000.serial: cts_event_workaround enabled
[    2.664576] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 81, base_baud = 0) is a PL011 rev2
[   10.590168] uart-pl011 3f201000.serial: no DMA platform data

I still think my issue is not with the RPi as it functions ok with my MK3.

RE: MK4 - Octoprint cannot connect

Which port does OctoPrint use (or want to use) to connect to the MK4?

RE: MK4 - Octoprint cannot connect

Do you have something like this in your settings? This could help make the port known to OctoPrint.

RE: MK4 - Octoprint cannot connect

This serial port is the only available.

RE: MK4 - Octoprint cannot connect

Did you try to enable the auto-connect option?

Could you enable the serial.log and post the log file after a reboot of the Pi? Perhaps we can see a problem in there.

RE: MK4 - Octoprint cannot connect

dmesg after plugin in usb cable:

usb 1-1.2: new full-speed USB device number 5 using dwc_otg
usb 1-1.2: New USB device found, idVendor=2c99, idProduct=000d, bcdDevice= 1.00
usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1.2: Product: Original Prusa MK4
usb 1-1.2: Manufacturer: Prusa Research (prusa3d.com)
usb 1-1.2: SerialNumber: XXXXX-YYYYY
cdc_acm 1-1.2:1.0: ttyACM0: USB ACM device
usbcore: registered new interface driver cdc_acm
cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters

Serial log after trying to connect: (Connecting with AUTO gave a much longer log)

Changing monitoring state from "Offline" to "Detecting serial connection"
Performing autodetection with 1 port/baudrate candidates: /dev/ttyACM0@115200
Trying port /dev/ttyACM0, baudrate 115200
Handshake attempt #1 with timeout 2.0s
Connected to: PackingSerial<id=0x7161ff90, open=True>(port='/dev/ttyACM0', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=2.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
Send: N0 M110 N0*125
Handshake attempt #2 with timeout 2.0s
Send: N0 M110 N0*125
Handshake attempt #3 with timeout 2.0s
Send: N0 M110 N0*125
Changing monitoring state from "Detecting serial connection" to "Error"
Changing monitoring state from "Error" to "Offline after error"
Connection closed, closing down monitor

But then I connected the MK4 to my Windows pc and got success with connecting printrun/pronterface. The MK4 must be ok.

I installed for test a fresh new Octopi on a Pi4 and... That worked! I got a near perfect Bed Leveling Visual for my new MK4.

Strange that the three year old Pi3b+ setup will not connect, I will leave it as long as the MK3 stays here. If I might decide not to use PrusaLink I will setup a new Octoprint on a Rpi Zero 2W for the MK4.

Thank you for your time.

RE: MK4 - Octoprint cannot connect

Glad you got it working. Installing a new copy of OctoPrint on a new MicroSD would have been my next suggestion. The latest images have gotten so much better at working out of the box, e.g. with the newer Pi Camera modules. To update I create a backup of my current config, then I flash the latest image onto a new MicroSD, start the setup and then just upload my backup from the old version. After restoring the backup the new system has practically all the settings and plugins from before. And as I do not want to keep old gcode files, the new system is usually also leaner and faster than the old one was.