Cloned from KotelloRC's bitbucket: https://bitbucket.org/KotelloRC/erfly6.git for my reference
ErFly6 - new (good forgeted old) project porting er9X for family of radio FlySky FS-i6, FS-i6x. Build firmware - Segger Embedded Sudio Flash firmware via J-Link (clone) or ST-Link (for FS-i6X). To build firmware install https://www.segger.com/downloads/embedded-studio/
In File menu choose Open Solution, and Select FSI6.emProject from folder where it placed.
Choose Active Project which suitable for your radio - FSI6 or FSI6X. Build project. If build successful flash firmware.
RF module A7105 only wit AFDHS 2A protocol. AFDHS protocol now not support. Trainer mode (PPM in and PPM out) supported.