NMEA Protocol Guide
NMEA 0183 is the standard protocol for GPS and navigation data communication. Learn how Stratux uses NMEA sentences to provide position, altitude, and navigation data to EFB apps.
What is NMEA?
NMEA 0183 is a communication standard developed by the National Marine Electronics Association for marine electronics. It has become the de-facto standard for GPS receivers and navigation equipment worldwide, including aviation applications.
NMEA sentences are ASCII text strings that start with a '$' character, followed by a talker identifier (like 'GP' for GPS), a sentence type (like 'GGA' for fix data), and comma-separated data fields. Each sentence ends with a checksum for error detection.
Stratux can output NMEA data alongside GDL90, making it compatible with a wider range of navigation applications and legacy equipment that may not support the GDL90 protocol.
Common NMEA Sentences
$GGAGPS Fix Data
Contains time, position, altitude, and fix quality. Most important sentence for aviation navigation.
$RMCRecommended Minimum
Time, date, position, course, and speed. Essential for moving map displays.
$GSAGNSS DOP & Satellites
Satellite IDs used for fix, PDOP, HDOP, VDOP values for accuracy assessment.
$GSVSatellites in View
Lists all visible satellites with elevation, azimuth, and signal strength.
$VTGCourse & Speed
Track made good and ground speed in knots and km/h.
$GLLGeographic Position
Latitude and longitude with time and status.
NMEA in Stratux
Stratux primarily uses the GDL90 protocol for traffic and GPS data transmission to EFB apps. However, NMEA output can be enabled for compatibility with applications that require it.
When enabled, NMEA sentences are broadcast over the Stratux WiFi network on a configurable TCP or UDP port. This allows legacy navigation software, marine chartplotters, and other NMEA-compatible devices to receive GPS data from Stratux.
The NMEA output includes position (GGA, RMC), satellite info (GSA, GSV), and speed/heading data (VTG). This data comes from the same GPS receiver that provides position for GDL90 traffic display.
NMEA vs GDL90
| Feature | NMEA 0183 | GDL90 |
|---|---|---|
| Primary Use | GPS/Navigation data | Traffic + GPS data |
| Data Format | ASCII text sentences | Binary protocol |
| Traffic Support | No (GPS only) | Yes (ADS-B, FLARM) |
| AHRS Support | Limited | Full support |
| EFB Support | Some apps | All major apps |
Frequently Asked Questions
Stratux: GDL90 + NMEA Support
Our Stratux devices support both GDL90 for modern EFB apps and NMEA for legacy compatibility. Get the best of both worlds.
Related Technology Guides
Disclaimer
Stratux is not certified aviation equipment. It does not replace a transponder or relieve the pilot of traffic awareness responsibilities. Use as supplementary situational awareness only. Dross:Aviation assumes no responsibility or liability for the use of Stratux devices, firmware flashing, or hardware modifications. All DIY guides are provided without warranty-use at your own risk.