In keyer_features_and_options.h , uncomment ( // ) the features you want to use (e.g., #define FEATURE_LCD_I2C ).
Depending on your needs, builders often "repack" the project into these configurations: k3ng keyer schematic repack
Where you map the physical Arduino pins to the functions mentioned in the schematic above. In keyer_features_and_options
A robust K3NG keyer project, using a re-packed schematic, generally requires the following components: using a re-packed schematic