Trimble MB-Two
The Trimble MB-Two RTK GPS receiver is a high-end, dual-frequency RTK GPS module that can be configured as either base or rover.
Required Firmware Options
The following firmware options need to be selected when buying the device:
- [X] [2] [N] [G] [W] [Y] [J] for 20Hz position updates and RTK support, 1cm horizontal and 2cm vertical position accuracy
- [L] LBAND
- [D] DUO - Dual Antenna Heading
- [B] BEIDOU + [O] GALILEO, if needed
Antennas and Cable
The Trimble MB-Two requires two dual-frequency (L1/L2) antennas. A good example is the Maxtenna M1227HCT-A2-SMA (which can be bought, for instance, from Farnell).
The antenna connector type on the device is MMCX. Suitable cables for the above antennas (SMA connector) can be found here:
Wiring and Connections
The Trimble MB-Two is connected to a UART on the flight controller (GPS port) for data.
To power the module you will need a separate 3.3V power supply (the maximum consumption is 360mA).
INFO
The module cannot be powered from a Pixhawk.
The pins on the 28-pin connector are numbered as shown below:
| Pin | Name | Description |
|---|---|---|
| 6 | Vcc 3.3V | Power supply |
| 14 | GND | Connect to power the supply and GND of the Autopilot |
| 15 | TXD1 | Connect to RX of the Autopilot |
| 16 | RXD1 | Connect to TX of the Autopilot |
Configuration
First set the GPS protocol to Trimble (GPS_x_PROTOCOL=3).
Configure the serial port on which the Trimple will run using GPS_1_CONFIG, and set the baud rate to 115200 using SER_GPS1_BAUD.
INFO
PX4 doesn't use the MB-Two's dual-antenna heading.