Create_Project

Create Project in PlatformIO

First you need to create a new project with platformio.
Select your board and after creation open the platformio.ini.
Here add the following lines:

board_build.core = earlephilhower
lib_ldf_mode = deep+
lib_deps = 
	https://github.com/thelsing/knx
build_flags = 
	-DPIO_FRAMEWORK_ARDUINO_ENABLE_RTTI
	-DLWIP_DONT_PROVIDE_BYTEORDER_FUNCTIONS
	-DMASK_VERSION=0x07B0

Read more about the Flags here.

Mask Version

In the platformio.ini you have to set a Mask Version (Only if you don't define KNX_NO_AUTOMATIC_GLOBAL_INSTANCE).

Version	Medium
0x07B0	TP
0x57B0	IP
0x27B0	RF
0x091A	IP/TP
0x2920	TP/RF