My SV08 now shows “System Booting” and then blank screen after updating Eddy MCU firmware from the USB that came with the kit, and downloading latest klipper from Sovol Firmware website, which is 2.5.0.
Web interface loads and shows this:
MCU Protocol error This is frequently caused by running an older version of the firmware on the MCU(s). Fix by recompiling and flashing the firmware. Your Klipper version is: v0.12.0-0-g02eeceb-dirty MCU(s) which should be updated: mcu: Current version v0.12.0-0-g02eeceb-dirty-20250528_031841-SPI-XI extra_mcu: Current version v0.12.0-0-g02eeceb-dirty-20250528_031841-SPI-XI Up-to-date MCU(s): <none> Once the underlying issue is corrected, use the "RESTART" command to reload the config and restart the host software. mcu 'extra_mcu': Command format mismatch: query_adxl345 oid=%c clock=%u rest_ticks=%u vs query_adxl345 oid=%c rest_ticks=%u
Did you flash BOTH MCUs with the new firmware from the update package? Others have had issues with the Sovol provided programmer. Try again on the lowest speed setting.
I flashed both the toolhead and bottom main board with the Sovol provided programmer with the SV08 klipper.bin from the provided USB. ST-Link was ran at 4MHz. But I made sure to see both runs say Verification.... OK
And then I downloaded firmware 2.5.0 from Sovol Firmware website. Formatted the USB as FAT32 4096 blocks, put only the 2.5.0 deb file in the drive, and put the drive into SV08.
I let it sit there for 5-10 minutes, the stock screen is blank. The web interface shows the error above. I put the USB back into a windows PC, the USB only has .ip.txt in it now, which indicates to me that it flashed the firmware.
The HOST (embedded on the mainboard) is booting. Klippy, Moonraker, and Fluidd or Mainsail are running or you couldn’t see the error.
The knob screen is a slave to the mainboard MCU. The “booting” screen is a static splash screen and means “no data from MCU yet”
You could look at printer.cfg in the web UI and verify [probe] is using the eddy. If so the HOST is updated to 2.5.0
Whatever version of Klippy is running on the embedded host is refusing to talk to either MCU due to a version mis-match.
Either neither MCU got updated OR both did and the Host didn’t.
Normally MCU firmware is backward compatible and the second scenario above wouldn’t error. Sovol could have edited Klippy to only accept one specific MCU firmware. I highly doubt that.
So your logical next step is reflash both MCUs with the correct .bin file for your hardware (3mm vs 4mm)
I see, the confusion is that there are 2 different Sovol Firmware pages – the website Download page, and the wiki. The correct MCU firmware and klipper deb were found on the wiki as @cardoc advises.