Running MavLink over T1 Ethernet

T1 Ethernet between FMUK66 and NavQ

Prerequisite

The RDDRONE-FMUK66 has a two wire 100BaseT1 Ethernet interface on board. The 8mmNavQ board does not include T1 Ethernet however an adapter may be used. To run the T1 Ethernet connection between FMUK66 and NavQ use a separate RDDRONE-T1ADAPT media converter.

The 8mpNavQ or "NavQPlus" will have two Ethernet interfaces. it is planned that one of these interfaces will natively be configured as 100BaseT1

Setting a fixed IP to use Ethernet for FMU communication

It is not recommended to use DHCP in a vehicle such as a drone, since you generally don't want the network to change without knowing about the explicit details. Therefore since there is no DHCP and FMUK66 by default has a fixed IP of 10.0.0.2, we need to set a fixed IP on the NavQ for eth0 to be able to communicate via Ethernet to FMUK66.

It is suggested to use IP address 10.0.0.3 for navq.

connman connection manager

The linux program connman is used for configuring the network settings . To force connman to use a fixed IP ( as in case when no DHCP is available) the following file needs to be created.

It is important is that you have a Ethernet cable connection before, otherwise connman will not register the network.

~$ sudo nano /var/lib/connman/ethernet.config

[global]
Name = Ethernet_config
Description = Ethernet fixed IP setting

[service_onboard_ethernet]
Type = ethernet
IPv4 = 10.0.0.3/255.255.255.0/10.0.0.3

The IP4 settings are in the order of ownIP/netmask/router. Note that 10.0.0.3 is set as router since in this particular hardware configuration no other device is there.

Setting up FMUK66 for mavlink over T1 Ethernet

T1 Ethernet is supported by PX4 on FMUK66 with latest master.

To enable the RDDRONE-FMUK66 mavlink telemetry via UDP sending to a specific IP you must add the following file on the FMUK66 SDcard:

/etc/extras.txt

set +e
mavlink start -x -u 14551 -o 14551 -r 200000 -t 10.0.0.3 -m onboard
set -e

In the example configuration above, 10.0.0.3 is the IP address of NavQ on the vehicle. More detailed description of the mavlink start parameters can be found here: https://dev.px4.io/v1.9.0/en/middleware/modules_communication.html

Additionally the MAV_BROADCAST parameter on the FMU needs to be set to "2 - only multicast".

Distributing MavLink data can be done by installing mavlink-router on NavQ.