Guide:Marlin

Install PlatformIO

root_dir=$PWD
export PLATFORMIO_CORE_DIR=$root_dir/pio
git clone https://github.com/platformio/platformio-core-installer
cd platformio-core-installer && python3 get-platformio.py

Clone Marlin

We clone the version 2.1.2.1, the latest at the time of writing this guide.

git clone -b 2.1.2.1 https://github.com/MarlinFirmware/Marlin marlin
cd $root_dir

Clone example configurations (also for version 2.1.2.1), so we don't have to start from scratch.

git clone -b 2.1.2.1 https://github.com/MarlinFirmware/Configurations config

Find PlatformIO environment

Find the environment (a build preset/toolchain) to use with PlatformIO. We're compiling for Ender 3 v4.2.2 board, so use STM32F103RE_creality in "Build with PlatformIO" section.

If your printer or motherboard version is different, proceed with the steps below.

Search for similar lines in ./Marlin/src/pins/pins.h file:

grep CREALITY_V422 marlin/Marlin/src/pins/pins.h

./Marlin/src/pins/pins.h:575:  #include "stm32f1/pins_CREALITY_V422.h"
  / STM32F1
  / env:STM32F103RE_creality
  / env:STM32F103RE_creality_xfer
  / env:STM32F103RC_creality
  / env:STM32F103RC_creality_xfer
  / env:STM32F103RE_creality_maple

Choose the one that matches your board.

Configure

Optional: create a git branch specific for this printer, so all changes can be tracked and updated easily.

cd $root_dir/marlin
git checkout -b ender-3

Use the example config:

cp $root_dir/config/config/examples/Creality/Ender-3/CrealityV422/{_Bootscreen.h,Configuration_adv.h,Configuration.h,_Statusscreen.h} marlin/Marlin/

Optional: commit the changes, and do this every time the config is changed. Provide a description of the changes.

cd $root_dir/marlin
git add Marlin
git commit -m "Ender 3 example config"

Build with PlatformIO

Use the PlatformIO environment that we found before.

cd $root_dir/marlin
$root_dir/pio/penv/bin/platformio run -e STM32F103RE_creality

This builds a firmware file, and you can find it in the compilation output log:

RAM:   [=         ]  11.6% (used 7592 bytes from 65536 bytes)
Flash: [===       ]  27.2% (used 142600 bytes from 524288 bytes)
Building .pio/build/STM32F103RE_creality/firmware-20231008-230629.bin

Installation

Copy .pio/build/STM32F103RE_creality/firmware-20231008-230629.bin to the SD card. Do not rename it, otherwise the printer may refuse to update if the name is the same as the current firmware.

Insert the SD card and reset the printer. It should update itself during the boot.