mavlink-router

mavlink-router routes MavLink data dynamically between several end nodes

Introduction

To be able to have several end nodes communicating via mavlink simultaneously we need to set up mavlink-router on the NavQ. The end nodes can be

• A process for onboard control running on NavQ.

• A QGroundControl (QGC) computer the NavQ connects to via a data link such as WiFi.

• Other mavlink enabled peripherals on the vehicle.

• Another program running on the same remote PC as QGC

Prerequisites

Set up TELEM2 on the FMU

Connect to your FMU over USB and open QGroundControl. Navigate to Settings -> Parameters -> MAVLink and set these parameters:

Also, you'll need to make sure that the settings in Settings -> Parameters -> Serial look like this:

Installation and compiling mavlink router

To install and compile mavlink router follow the steps below (internet access required on your NavQ)

1) Connect to NavQ console via ssh / serial

2) Type the following commands

~$ mkdir src
~$ cd src
~/src$ git clone https://github.com/intel/mavlink-router.git
~/src$ cd mavlink-router 
~/src/mavlink-router$ git submodule update --init --recursive
~/src/mavlink-router$ ./autogen.sh && ./configure CFLAGS='-g -O2' --sysconfdir=/etc --localstatedir=/var --libdir=/usr/lib --prefix=/usr
~/src/mavlink-router$ make
~/src/mavlink-router$ sudo make install

Mavlink-router configuration

Configuration of mavlink router is done via a single configuration file /etc/mavlink-router/main.conf This file needs to be created from scratch. An example configuration file is available in the mavlink-router sources - https://github.com/intel/mavlink-router/blob/master/examples/config.sample

As of today the mavlink-router make install does not create the /etc/mavlink-router directory and main.conf file. Therefore please use the following commands to create the directory and file initially.

~$ sudo mkdir /etc/mavlink-router

~$ sudo touch /etc/mavlink-router/main.conf

Setup the config file with minimal configuration

~$ sudo nano /etc/mavlink-router/main.conf

#Mavlink router configuration navq
#
[General]
TcpServerPort=5760
ReportStats=false
MavlinkDialect=auto

[UartEndpoint FMUuart]
Device=/dev/ttymxc2
Baud=921600

[UdpEndpoint FMUeth]
Mode = Eavesdropping
Address = 0.0.0.0
Port = 14551

[UdpEndpoint QGConMobile]
Mode = Normal
Address = 192.168.43.1
Port = 14550

The configuration above assumes that the NavQ gets mavlink data from FMU either via UART3 (/dev/ttymxc2) or UDP. If you use UART please set on the FMU the corresponding serial port to 921600Bd. For this the SER_TELx_BAUD (x = number of telemetry port) parameter needs to be adjusted to 921600 8N. If you use lower speed QGroundControl might fail to load parameters.

You can leave out the unused connection. Via the UdpEndpoint QGConMobile section the mavlink stream is forwarded to a QGC computer/mobile device assuming it has 192.168.43.1 and NavQ is connected to this network via e.g. WiFi.

Enabling auto-start of mavlink-router

Enable the auto-start of mavlink-router via systemd and start it

~$ sudo systemctl enable mavlink-router
~$ sudo systemctl start mavlink-router

Checking status of mavlink-router

You can check the status of mavlink router using the command

~$ sudo systemctl status mavlink-router