Ender 3 4.2.7 printer is not ready

General Discussion
1

Basic Information:

Printer Model: Ender 3 Pro
MCU / Printerboard: Creality 4.2.7
Host / SBC: Pi Zero 2 W
klippy.log: klippy.log (110.7 KB)

I know there’s a lot of threads on this but I’ve tried everything and stuck with Printer Not Ready issue on Ender 3 Pro with 4.2.7 board. Any help would be much appreciated. Tried every option for firmware make but nothing seems to make a difference. Works fine if I revert to Marlin/Octoprint for connection.

2

It is very likely that the solution to your issue is one of the points listed here: Issues flashing the printer board

1 Like
3

Thanks for the reply. In my case listing the serial port works as expected returning /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0. One interesting thing I’m seeing the terminal is that it shows what appears to be firmware version from the printer but say connected at 0bps. I tried flashing with baud set to 115k but didn’t help. Has anyone else seen this?

23:06:30 Klipper: Connected to host
23:06:30 Connected to host via /tmp/printer @0bps
23:06:30 Firmware version: v0.12.0-468-gd679f711e
23:06:30 Printer is not ready
23:06:30 Printer is not ready
The klippy host software is attempting to connect. Please
retry in a few moments.

4

This is unrelated. Apparently you are trying to access Klipper with Octoprint. On older installations this “access path” defaulted to /tmp/printer. On your installation it would be /home/pi/printer_data/comms/klippy.serial.

According to your log above, your printer-board (Creality 4.2.7) does not properly talk to the Klipper host on the Pi Zero.
Again, the reason is almost surely one of the points listed in the linked guide above.

5

Tried the suggested serial in OctoPrint but it won’t connect. Only /tmp/printer seems to work. I’ve tried everything on the guide except Bootloader offset and Clock reference. Current settings are below. I’ve tried different cable, NoSWD, Only 10kiB, and 115k Baud but no difference. For OS tried OctoPi/KIAUH and manual Klipper install, MainsailOS/Moonraker, and generic PI using KIAUH. All return Printer not ready.

21:16:40 Klipper: Connected to host
21:16:40 Connected to host via None @0bps
21:16:40 Firmware version: v0.12.0-469-g52617455c
21:16:40 Printer is not ready
21:16:40 Printer is not ready
The klippy host software is attempting to connect. Please
retry in a few moments.

Klipper Firmware Configuration
[] Enable extra low-level configuration options
Micro-controller Architecture (STMicroelectronics STM32) —>
Processor model (STM32F103) —>
[ ] Only 10KiB of RAM (for rare stm32f103x6 variant) (NEW)
[ ] Disable SWD at startup (for GigaDevice stm32f103 clones) (NEW)
Bootloader offset (28KiB bootloader) —>
Clock Reference (8 MHz crystal) —>
Communication interface (Serial (on USART1 PA10/PA9)) —>
(250000) Baud rate for serial port
[] Optimize stepper code for ‘step on both edges’ (NEW)
() GPIO pins to set at micro-controller startup (NEW)

6

How did you obtain the serial?

[mcu]
serial = /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0
restart_method = command
7

From running ls. Here’s the output. Thx.

pi@mclpi:~ $ ls /dev/serial/by-id/*
/dev/serial/by-id/usb-1a86_USB_Serial-if00-port0

8

Got it connecting to /home/pi/printer_data/comms/klippy.serial but still getting printer not ready. Tried on Ubuntu via KIAUH.

Changing monitoring state from “Offline” to “Opening serial connection”
Connecting to port /home/pi/printer_data/comms/klippy.serial, baudrate 250000
Changing monitoring state from “Opening serial connection” to “Connecting”
Connected to: Serial<id=0x6ebdd0b8, open=True>(port=‘/home/pi/printer_data/comms/klippy.serial’, baudrate=250000, bytesize=8, parity=‘N’, stopbits=1, timeout=10.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
Send: N0 M110 N0125
Recv: ok
Send: N0 M110 N0125
Changing monitoring state from “Connecting” to “Operational”
Recv: ok
Send: N0 M110 N0125
Recv: ok
Send: N1 M11539
Recv: ok FIRMWARE_VERSION:v0.12.0-469-g52617455c FIRMWARE_NAME:Klipper
Send: M851
Recv: // Printer is not ready
Recv: // The klippy host software is attempting to connect. Please
Recv: // retry in a few moments.
Recv: !! Printer is not ready
Recv: ok

9
  1. Please always use the preformatted Text feature of the forum editor for code: How-To Ask for Help
  2. Are you sure you uploaded the correct firmware to the MCU?
  3. Is the printer up and running?
  4. You may also try: Put tape on the 5V pin - Why and how - FAQ - OctoPrint Community Forum
1 Like
10
  1. Thanks for that
  2. Yes, there looks like there’s only a couple variants of this board and tried both plus other setting changes
  3. Yes, just reverted back to OctoPrint/Marlin and everything works great
  4. Using a cable with 5v blocked but have tried other cables w/o this
11

Also check if the USB cable is able to transport data. There a lots of charging cables around without (not w/o) no data wires.

13

Yes, setup works fine with OctoPrint/Marlin. I’ve been switching back and forth for testing with no problems communicating with printer.

14

You are focusing on the wrong item. Throughout the last posts, you have been looking at the communication between Klipper and OctoPrint, which is irrelevant for your case.

What is not working is the communication between the printer board and Klipper. (For the last time), I’ll direct you to Issues flashing the printer board, as the solution is almost certainly among the listed items.

The relevant error lines are only visible in the klippy.log, for example:

serialhdl.error: mcu 'mcu': Serial connection closed

As long as you have these lines in your log, you don’t even need to bother looking into or using OctoPrint.