Hi everyone,
I'm happy to share AFS4 SeeYou Navigator Bridge — a free, open-source tool that connects Aerofly FS4 to the SeeYou Navigator app on your phone in real time.
For the moment it only works with glider self launch or starting a flight in the air - sim limitation.
What it does
The bridge reads flight data from Aerofly FS4 and sends it to SeeYou Navigator through the Naviter USB dongle (the same one used by Condor 3). SeeYou Navigator sees it as a real flight instrument — you get live position on the map, altitude, speed, vario, wind, and everything else SeeYou offers.
How it works
Aerofly FS4 → UDP/DLL → AFS4 SeeYou Bridge → Serial COM port → Naviter dongle → SeeYou Navigator (phone)The bridge generates standard NMEA sentences ($GPGGA, $GPRMC, $LXWP0) at 1 Hz, matching the exact same format that Condor 3 uses. This means SeeYou Navigator works with it out of the box — no special configuration needed on the phone side.
Two data modes
- UDP mode (default): Receives the standard ForeFlight broadcast from AFS4. Provides position, altitude, speed, heading, and calculated vario. Works out of the box.
- DLL mode (enhanced): When the AeroflyReader DLL is loaded, the bridge also gets indicated airspeed (converted to TAS), direct vario at 50 Hz (much smoother), and real wind data. The DLL is detected automatically.
Features
- GUI with COM port selector and live flight data display
- Standalone Windows executable — no Python installation needed
- Also runs from source with Python 3.7+ (only requires pyserial)
- Terminal mode available (--no-gui)
- Includes nmea_sniffer.py utility for debugging
Requirements
- Naviter USB Condor dongle
- SeeYou Navigator app on your phone, paired with the dongle
- Aerofly FS4 with default UDP settings (no changes needed)
- AeroflyReader DLL (optional, for enhanced data)
Download
- Standalone exe: GitHub Releases
- Source code: GitHub Repository
Free and open source (MIT License).
Technical notes
The project shares the same architecture as my AFS4-XCSoar bridge (also on GitHub). Both use the same UDP receiver and DLL reader, but output to different targets — TCP for XCSoar, serial for SeeYou Navigator.
Feedback and contributions welcome!
