This will be where I maintain the changes to the firmware applied to the
Ender-3 Pro 3D printer.

Marlin 2.0 supports 8-bit boards, like the stock Creality v1.1.3 motherboard,
but now has the added bonus of supporting 32-bit boards. Such board is the
Creality v1.1.5 motherboard which has silent motors. However, Creality has
upgraded that v1.1.5 board to v4.2.7, flashed a bootloader, and given it a
version of Marlin 2, but might need adjusting. Creality only provides the
firmware.bin file on their site, without specifying their settings.
The Marlin 2.0 firmware will work on the v1.1.3 board, but there will need to
be options disabled to make it all fit on the small flash size.

I purchased the v1.1.5 board, and received the upgraded v4.2.7 motherboard.
One of the benefits to this board is that it has a connector made for the
BLTouch auto-leveling tool. I purchased this and used it on the v1.1.3 before
upgrading motherboards; worth it!

I will not include the firmware setup for Marlin 2 on the v1.1.3 board, as it
is not complete with all the features I had with v1.1.9; too many sacrifices
adding BLTouch on Marlin firmware.

NOTE: Marlin 2.0 firmware will refer to the v4.2.7 motherboard, including the
addition of BLTouch to the Ender-3 Pro 3D printer.

There is no ISP port on the v4.2.7 board, and firmware flashing is done via
USB or the microSD card. Additionally, the USB port changed from mini-USB to
micro-USB.

Building the firmware is done through Visual Studio Code, along with the
PlatformIO IDE and Auto Build Marlin plug-ins. There will be changes needed
in the platformio.ini file, to ensure the proper board is used for compiling
through the Auto Build Marlin plug-in.