README.md

How to Dump Neptune 4 MCU Firmware

Warning: Only flash this firmware on a DE-ELEGOO setup/image, not on stock Elegoo software.

Solder a Momentary Button:
- Solder a momentary (push to make) button on the BOOT pads on the MKS/Elegoo control board next to the RESET button.
- Alternatively, further on you will need to bridge these with sharp metal tweezers.
Power On and Boot Process:
- Power on the machine.
- Press the BOOT button down (or bridge the pads).
- While this is pressed, also press the RESET button next to it.
- Release RESET then BOOT.
SSH and Commands:
- Leave the printer on, and SSH in (as mks) and type:
```
sudo service klipper stop
sudo apt update
sudo apt install stm32flash
cd ~/
stm32flash -r firmware-bak.bin /dev/ttyS0
```
- If this errors out, repeat the BOOT/RESET button-press routine above until it works.
Copy Firmware Backup off the Machine (Optional):
- From another terminal on the computer, copy this off your printer using:
```
scp mks@IPADDRESS:/home/mks/firmware-bak.bin .
```
Reboot:
- Type sudo reboot (then power cycle after a few minutes).

(Only do this if you have removed Elegoo services and are running standard/updated releases of Klipper.)

Enter Bootloader Mode:
- Power on the machine.
- Press the BOOT button down (or bridge the pads).
- While this is pressed, also press the RESET button next to it.
- Release RESET then BOOT.
SSH and Commands:
- Leave the printer on, and SSH in (as mks) and type:
```
cd /home/mks/klipper/
make clean
make menuconfig
```
- Enter the following configurations using arrow keys and SPACEBAR to select.
- STMicroelectronics STM32 - STM32F401 - 32KiB Bootloader - and USART PA10/PA9 - settings.
- Once you have selected the correct options hit the Q key and then Y to close and save.
- Now run:
```
make
```

Flash Klipper Firmware:

Then, type:

sudo service klipper stop
stm32flash -w /home/mks/klipper/out/klipper.bin -v -S 0x08008000 -g 0x08000000 /dev/ttyS0

Reboot:
- Type sudo reboot (then power cycle after a few minutes).
If this doesn't work (usually if you flashed MCU firmware before):
- Repeat the BOOT and RESET process.
- Download the provided firmware-bak.bin (in this git repo)
- Then, flash it with:
```
sudo service klipper stop
stm32flash -w ./firmware-bak.bin -v /dev/ttyS0
```
- After this reboot going forward you may use the first (compile with make menuconfig) method.
How to Recover OG MCU Firmware

(Pre-dumped N4Pro (might be the same as N4) firmware-bak.bin)

Power On and Boot Process:
- Similar to the above steps.
SSH and Commands:
- Leave the printer on, and SSH in (as mks) and type:
```
sudo service klipper stop
stm32flash -w firmware-bak.bin -v /dev/ttyS0
```
- If this fails, retry the BOOT & RESET button method above and re-run the stm32flash command.
- Type sudo reboot (then power cycle after a few minutes).