'mcu' has deprecated code

[theshining97]

I saw that this question had been answered before by recommending updating the MCU firmware following the guide in the Wiki. I've tried this multiple times.

This is a new installation. The warning is: "MCU 'mcu' has deprecated code (it is missing feature 'STEPPER_STEP_BOTH_EDGE'). Recompiling and flashing is recommended (MCU version '047b8fe-dirty-20230703_160308-mkspi', host version 'v0.13.0-756-g2d7717e3')."

I don't really undertand the difference between MCU version and "host" version but I am not sure what else to try. At one point I noticed a recommendation to upgrade PIP from 25.3 -> 26.2.1 and I did that with no effect.

I also noticed the guide mentioned that one of the files on the SD card will be renamed from .bin to .CUR. I do not believe that has happened here.

Any advice is appreicated.

[barry166]

The host version is the Klipper code running on the Linux board; the MCU version is the firmware currently flashed to the printer’s controller. This warning means the host was updated to a commit that expects STEPPER_STEP_BOTH_EDGE, while the controller still has an older MCU build.

Updating pip will not fix that mismatch. Rebuild/flash the matching MCU firmware from the OpenNept4une Flashing / Updating Klipper MCUs guide, using the files for your exact Neptune model and board. A successful SD-card flash normally consumes/renames the .bin file to .CUR; if it remains .bin, the bootloader likely did not accept that file (wrong filename/model, card layout, or flash procedure). After flashing, restart Klipper and confirm the host and MCU report the same generation. The earlier OpenNept4une discussion on this exact warning and the MCU update guide cover the same distinction.

[theshining97]

thank you for the reply. I am hoping to find out where I am going wrong.

I can see in the command window when (I think) the firmware is compiled that the version is:

     Building out/compile_time_request.o
     Loaded configuration '/home/mks/klipper/.config'
     Minimal configuration saved to 'out/defconfig'
     Version: v0.13.0-756-g2d7717e3
       Linking out/klipper.elf
       Flashing
     Installing micro-controller code to /usr/local/bin/
     Attempting host MCU restart...
     
     Virtual MCU update completed.

And that matches what I see in the Fluidd interface after reboot:

     linux
     50 MHz
     v0.13.0-756-g2d7717e3

I thin that means the printer has the intended firmware version running.

Assuming the bin files are created based on the host version, how do I fix this?

[zBashar]

Hey! That warning pops up because your host Klipper updated to v0.13.0, but your physical mainboard MCU is still stuck on the old stock firmware (20230703...). The OpenNept4une script updated the virtual host MCU, but the motherboard hasn't actually flashed the new .bin file yet.

Here is how to get the mainboard to accept the update:

• Re-generate the firmware: SSH into your printer (ssh mks@), run opennept4une, go to Option 4 (Update MCU & Virtual MCU Firmware), and select All. (If it asks about an external USB Pico/ADXL and you don't have one, just press s to skip).

• Download files to your PC: In Fluidd's configuration/file editor, locate and download the generated .bin files (usually elegoo_k1.bin or X_4.bin).

• Format the SD Card: Use a MicroSD card 32GB or smaller, formatted to FAT32 with 4096-byte cluster size.

• Rename the file: Copy the .bin file to the root of the SD card. Crucial step: Rename it to something unique like elegoo_k2.bin or firmware1.bin. The Elegoo bootloader ignores filenames it has already processed in the past.

• Flash the motherboard: In Fluidd, click the Power icon (top right) and choose Shutdown Host. Once off, turn the power switch off, insert the MicroSD card directly into the motherboard slot (the internal one under the printer, not the screen or host USB slot), and power back on. Give it 2–3 minutes to flash.

• Verify: Power down, pull the SD card, and check it on your PC. If the file changed to .CUR (e.g., elegoo_k2.CUR), means it worked.

Once you boot up and hit Firmware Restart in Fluidd, the versions will match and the warning will disappear.