A debugging/programming probe (e.g., ST-Link, J-Link, or Black Magic Probe) is required to flash the the OpenBLT bootloader for Anet ET4/ET5 series printers due to incompatibility with the stock bootloader. Once OpenBLT is flashed, Marlin can be updated by SD card just like the original firmware.
Using three female to female Dupont jumper cables, connect GND
, SWDIO
, and SWCLK
pins from the ST-Link to the Serial Wire Debug (SWD) header on the motherboard. Pay close attention that the cables on SWD header side match the order below using the U
and G
letters printed on the motherboard as a reference:
SWD Header on ET Series motherboard
___
U | o | (not connected)
|---|
| o | SWDIO
|---|
| o | SWCLCK
|---|
G | o | GND
---
Photo reference:
GND
is connected to GND
(black wire), SWDIO
to SWDIO
(yellow wire), and SWCLK
to SWCLK
(green wire). Your ST-Link pinout may differ from the one pictured, so double-check pinout.
Plug in the ST-Link to your computer's USB port & power on your printer.
Download & install STM32 ST-Link Utility.
Launch STM32 ST-Link Utility & click Target
then Connect
.
Back up the original motherboard firmware starting at address 0x08000000
with a size of 0x100000
:
Download & extract OpenBLT bootloader for Anet ET4/ET5 series printers.
Click on Target
then Program...
Set the Start Address
to 0x08000000
.
Under File Path
, click Browse
and select openblt_et4.bin
extracted in Step 6.
Click Start
to initiate the flashing process.
OpenBLT for Anet ET4/ET5 series printers is now installed on your motherboard.
Anet_ET4_OpenBLT
PlatformIO environment.Marlin/.pio/build/Anet_ET4_OpenBLT/firmware.srec
to a blank SD card and insert it into your printer.