¶ NMEA output over UART
This article shows how to make Zubax GNSS output the navigation data via the physical UART port.
¶ Parts needed
The only part that will be needed (aside from one Zubax GNSS) is a cable with a JST SH 6-pin connector on one end (also known as DCD-M (Dronecode Debug Mini) connector). It can be purchased from many sources online. The cable is pictured here:
JST SH 6-circuit cable (DCD-M)
¶ Configuring Zubax GNSS
The NMEA output over UART is disabled by default, so we need to enable it. Connect USB, open the command-line interface (CLI) at 115200 baud, then execute the following:
Enabling NMEA UART output
cfg set nmea.uart_on 1
cfg save
reboot
If necessary, also enable the altimeter or configure other features, as shown in the datasheet.
The NMEA output should be kept disabled if it is not used.
¶ Connecting to the UART port
Connect one end of the cable to Zubax GNSS 2’s DroneCode port using the following pinout specification.
| Pin | Type | Name | Comment |
|---|---|---|---|
| 1 | Power | +5VDC |
+5 V power supply input. The board can be powered from other sources as well; read the datasheet for more info. |
| 2 | OUT | UART_TX |
NMEA output at 115200–8N1. |
| 3 | N/C | Leave floating. | |
| 4 | N/C | Leave floating. | |
| 5 | N/C | Leave floating. | |
| 6 | GND | GND |
Ground |
Connect the other end of the cable to your hardware, and configure the UART interface as follows:
- Baud rate: 115200
- Byte size: 8
- Parity: None
- Stop bits: 1
Zubax GNSS with a UART cable connected
¶ Testing
Now power on the device, and your hardware should be able to read the NMEA stream coming out of the UART port. A sample NMEA output is provided below.
NMEA output example
$GPRMC,072626.30,A,0036.27144,N,00042.93538,E,1.097,235.8,141215,,*35
$GPGGA,072626.30,0036.27144,N,00042.93538,E,1,14,1.44,239.382,M,13.2,M,,*5E
$GPGSV,4,1,15,08,52,283,17,10,80,126,26,14,27,155,34,15,15,039,08*74
$GPGSV,4,2,15,16,00,216,16,18,49,073,13,21,25,109,22,22,77,181,25*7F
$GPGSV,4,3,15,27,59,219,15,32,03,232,16,01,74,188,27,02,19,214,17*76
$GPGSV,4,4,15,08,47,047,22,23,29,145,21,24,80,177,18*4A
$HCHDG,266.0,,,,*40
$YXXDR,P,0.98966,B*57
$YXXDR,C,29.9,C*7F
$GPRMC,072626.36,A,0036.27143,N,00042.93547,E,1.402,235.8,141215,,*34
$GPGGA,072626.36,0036.27143,N,00042.93547,E,1,15,1.44,239.467,M,13.2,M,,*5A
$GPGSA,A,3,08,10,14,18,21,22,27,01,02,23,24,12,2.24,1.44,1.71*04
$HCHDG,266.2,,,,*42
$YXXDR,P,0.98968,B*59