Klipper on the BIQU BX V3

biqu_bx_klipper_v3.md

Klipper on the BIQU BX V3

NOTE: If you have a V2 board/screen(HDMI),click here

First, a few requirements:

1. You need Klipper setup on your Raspberry PI ( borad that support DSI) with your favorite control interface (Octoprint, Fluidd, Mainsail, etc..).
   • I recommend installing official Raspberry Pi OS
     • Download this file https://downloads.raspberrypi.com/raspios_armhf/images/raspios_armhf-2023-05-03/2023-05-03-raspios-bullseye-armhf.img.xz and use the Raspberry Pi Installer and select custom image.
2. Install the Drivers for V3 screen https://github.com/bigtreetech/BIQU-BX/tree/master/Firmware/RPi-Linux-RPi-7inch-DSI
3. You need your favorite Touchscreen UI installed (unless you just want to run headless).
   • Use this to install all you need https://github.com/dw-0/kiauh
     • If you have a issue with the screen is black, press the smal button under the turn knob
4. You MUST have removed the Z endstop physical switch. Not disconnected, but completely removed.

NOTE: CAN will not work on this board due to a hardware mis-configuration
NOTE: I2C is not quite working yet!

Ok, so let's get started.

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Klipper firmware configuration

When configuring the klipper firmware to run on the BTT SKR SE BX board, there are a couple things to know about.

1. Use the main klipper branch.
2. In order for the toucscreen to work, you will need to set GPIO pins PB5 and PE5 to an initial state during the config
3. Use the config/printer-biqu-bx-2021.cfg file for your intial printer.cfg
4. Once you are setup, you will need to calibrate your sensorless homing: https://www.klipper3d.org/TMC_Drivers.html?h=sensorless+ho#sensorless-homing

A note on connection methods:

There are 4 different connections you can make from the Raspberry Pi to the mainboard, 2 Serial and 2 USB.

• Serial (on UART4 PA0/PA1) <--- For v3 board/screen you need to use this

To use serial connections, you have to enable the serial port on the raspberry pi and compile the correct serial port for the BX mainboard. Once you have the serial port enabled on the raspberry pi, it will show up as /dev/ttyAMAx, with x being the port number.

Once you have it setup, your printer.cfg should then contain the following under the MCU section: serial: /dev/ttyAMAx, substituting the x for your port number.

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HDMI configuration

As v3 uses DSI you don't need any HDMI settings

Drivers for V3 screen

• Go to and follow the guide https://github.com/bigtreetech/BIQU-BX/tree/master/Firmware/RPi-Linux-RPi-7inch-DSI

Config.txt

Example on /boot/config.txt

Make sure this are in the config.txt file, some wil be added by the drivers installation skript.
[all]
dtparam=i2c_vc=on
dtparam=i2c_arm=on
enable_uart=1
dtoverlay=disable-bt
dtoverlay=vc4-kms-dsi-btt-bxv3-7inch
disable_splash=1

Slicer configuration

For your slicer, you need to call the PRINT_START macro instead of any preliminary gcode. The NOZZLE and BED temps get passed in as arguments. Some examples for the more popular slicers:

• Cura: PRINT_START BED={material_bed_temperature_layer_0} NOZZLE={material_print_temperature_layer_0}
• PrusaSlicer: PRINT_START NOZZLE=[first_layer_temperature] BED=[bed_temperature]
• Ideamaker: PRINT_START NOZZLE={temperature_heatbed} BED={temperature_extruder1}
• Simplify3D: PRINT_START NOZZLE=[extruder0_temperature] BED=[bed0_temperature]
• Kiri:Moto: PRINT_START NOZZLE={temp} BED={bed_temp}

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Klipper Functionality

Here are some notes on how I have Klipper setup and working quite well for my machine.

Touchscreen Sleep

The Touchscreen will go dark when the printer idle timeout occurs. This happens when there is not a print job in action and currently set for 5 minutes. Pressing the Menu Knob on the display will wake up the Touchscreen.

LEDS

The Neopixels are setup and will cycle through colors on bootup. I have the idle timeout set to shut off the LEDS when the printer is inactive. The LEDs automatically come on when a print is started or when the LCD is wakened.

Homing Routine

I have programmed a reliable homing routine that works well for me, however you can adjust or setup your own to taste. My routine will do the following:

1. Raise the Z axis
2. Home the X axis
3. Home the Y axis
4. Move the probe to the center of the bed (different than the nozzle at center)
5. Home the Z with the probe.

• When starting a print, additionally:

6. After the bed reaches temp, the printer waits for 90 seconds with the probe close to the bed to warm up the probe.
7. Steps 1-5 are repeated with a warm probe
8. Move to the origin to start the print.

@valpackett can this be scripted? Just to make it easier for most using this printer ?

Hi everyone!

I have a BIQU BX with a V3 board and a Raspberry Pi 3B+, currently running Marlin with OctoPrint since 2023. I'm planning to switch to Klipper and, after thoroughly reviewing the documentation, I feel confident about the process.

However, I’d like to ensure I have a rollback option in case something goes wrong. Does anyone know if the binary available in the following repository is compatible with the V3 board?

🔗 https://github.com/bigtreetech/BIQU-BX/tree/master/Firmware/Copy%20to%20microSD%20to%20update

Any help is greatly appreciated!

Rollbacks would to have the the old firmware and use a new sdcard for your klipper.

Rollbacks would to have the the old firmware and use a new sdcard for your klipper.

That's exactly the problem: I'm not sure if the firmware available in the BIGTREETECH repository is the V3 version that's compatible with my printer.

It worked! I followed the instructions and now Klipper is installed on my printer.

Thanks a lot for your help!

Rollbacks would to have the the old firmware and use a new sdcard for your klipper.

That's exactly the problem: I'm not sure if the firmware available in the BIGTREETECH repository is the V3 version that's compatible with my printer.

You can use the community version.

Hi everyone!

I managed to install Klipper and set everything up, but I'm still not satisfied with the print quality. I'm getting an accelerometer to enable input shaping and see if that improves the results.

I also miss having a working filament change macro. I haven’t been able to create one that works as well as what I had with Marlin. On top of that, I'm getting overheating errors on the Z-axis drivers:

TMC 'stepper_z' reports error: DRV_STATUS: c0170103 otpw=1 (OvertempWarning!) ot=1 (OvertempError!) t120=1 cs_actual=23 stealth=1 stst=1

Can anyone help me properly set up sensorless homing for the Z axis? Also, is it necessary to physically jumper the DIAG pin to PB13 on the board for this to work? If so, could someone explain exactly where those pins are located on the Biqu BX and how to wire them?

If anyone could share their printer.cfg, it would be really helpful so I can compare and see what I can improve in my setup.

I really appreciate any help!

can you access this ? https://github.com/varazir/KlipperBXBackup/tree/2727dc40ea7f8b8fa28e30c6faf9d3aba017192c/config

can you access this ? https://github.com/varazir/KlipperBXBackup/tree/2727dc40ea7f8b8fa28e30c6faf9d3aba017192c/config

No, error 404.

can you access this ? https://github.com/varazir/KlipperBXBackup/tree/2727dc40ea7f8b8fa28e30c6faf9d3aba017192c/config

No, error 404.
I added you as colab on the repo

can you access this ? https://github.com/varazir/KlipperBXBackup/tree/2727dc40ea7f8b8fa28e30c6faf9d3aba017192c/config

No, error 404.
I added you as colab on the repo

I was able to access it now, thank you!

Did you have to jumper the DIAG pin to the stepper driver for the Z axis? I checked your configuration and it’s identical to mine, but I keep getting frequent overheating warnings on the Z stepper driver.

can you access this ? https://github.com/varazir/KlipperBXBackup/tree/2727dc40ea7f8b8fa28e30c6faf9d3aba017192c/config

No, error 404.
I added you as colab on the repo

I was able to access it now, thank you!

Did you have to jumper the DIAG pin to the stepper driver for the Z axis? I checked your configuration and it’s identical to mine, but I keep getting frequent overheating warnings on the Z stepper driver.

Never change that. Maybe check on the Facebook https://www.facebook.com/groups/1012996125813700 forum or https://discord.gg/zBnEGScT you can find pinouts here https://github.com/bigtreetech/BIQU-BX

Now that I've noticed, the 5020 fan on the board isn't turning on.

Any tips?

Now that I've noticed, the 5020 fan on the board isn't turning on.

Any tips?

it should be on when you start printing.
I guess you can map the port in the config.

Now that I've noticed, the 5020 fan on the board isn't turning on.
Any tips?

it should be on when you start printing. I guess you can map the port in the config.

After a thorough check of the wiring diagram, comparing my settings to yours, and even swapping out the fan port and testing with another 24V fan, I finally pinpointed the problem: the 5020 fan had died. I'm still unsure if it was an existing issue that Marlin simply didn't report, or if something went wrong during the Klipper migration. A new fan is already on its way. I appreciate your patience throughout this process.