Flashing the MCU without a MicroSD (Old Method) - OpenNeptune3D/OpenNept4une GitHub Wiki

Tools & Prerequisites

  • Printer’s MKS/Elegoo mainboard accessible
  • Sharp metal tweezers (for bridging)

Step-by-Step

  1. Locate the unpopulated BOOT switch pads next to the RESET button on the mainboard.
    You will bridge these pads later.

  2. Power the printer on with the mainboard still accessible.

  3. SSH into the printer:

ssh mks@<printer_ip>
  1. Update packages and install stm32flash:
sudo apt update
sudo apt install stm32flash
  1. Launch OpenNeptune:
opennept4une

  1. In the menu choose:
    4) Update MCU & Virtual MCU Firmware → 1) STM32

  2. Wait for the compilation to finish.
    When prompted, ignore any extra notes and type y.
    Leave the printer powered on.

  3. Exit OpenNeptune (type q⏎).

  4. Stop Klipper:

sudo service klipper stop

  1. Enter bootloader mode
    a) Bridge the BOOT pads with tweezers.
    b) While bridged, press the RESET button.
    c) Release RESET, then remove the bridge.

  2. Flash the firmware:

stm32flash -w ~/printer_data/config/Firmware/X_4.bin -v /dev/ttyS0
  1. Firmware should now be updated.

Troubleshooting

If flashing fails, repeat Step 10 & 11 until it succeeds.

Add a custom footer
⚠️ **GitHub.com Fallback** ⚠️