This sensor based on a SeeedStudio XIAO SAMD21 reads from a GPS module and sends GPS telemetry values using the CRSF protocol, which can be consumed by an appropriate ELRS radio control receiver, for example a RadioMaster ER4, ER6 or ER8.
The GPS module can be disabled using a switch on the transmitter to save power when its not needed.
Current meassurements show this sensor takes 80-90mA with the TOPGNSS GG-1802 GPS module used.
The following configuration is optimised for a yacht, you may need to alter the Dynamic Model for a plane.
The TinyGPSPlus library parses only the $GPGGA and $GPRMC NMEA sentences, so all others are turn off to reduce the serial load on the SAMD21 at the 3Hz GPS update rate configured.
Configure the following in the View->Configuration View of the u-blox u-center application:
- PRT->Baudrate: 57600
- RATE->Measurement Period: 333ms
- PMS->Setup ID: 0 - Full Power
- NAV5->Dynamic Model: 3 - Portable
- GNSS: GPS and SBAS only enabled
- MSG->Message->F0-01 NMEA GxGLL: uncheck all
- MSG->Message->F0-02 NMEA GxGSA: uncheck all
- MSG->Message->F0-03 NMEA GxGSV: uncheck all
- MSG->Message->F0-05 NMEA GxVTG: uncheck all
- Red - flashes once every two seconds after CRSF protocol is started.
- Blue - flashes once for every NMEA message received from the GPS.
- Green - flashes once per telemetry message over CRSF, once a GPS fix is obtained.
- SAMD21 GND -> GNSS GND
- SAMD21 5V -> GNSS VCC
- SAMD21 D9 -> GNSS TX
- SAMD21 D10 -> GNSS RX
- SAMD21 5V -> Recv +
- SAMD21 GND -> Recv -
- SAMD21 TX -> Recv CRSF RX
- SAMD21 RX -> Recv port TX
- GPS
- GSpd
- Hdg
- Alt
- Sats
