Pixhawk TELEM2 is internally connected to Jetson module. Let us first check the connection on Jetson terminal. Consider having MAV connection to companion computers in advance. Check PX4 Docs for the details. For a sanity check you could run mavlink shell on /dev/ttyTHS1
Ethernet Connection
Since there is no DHCP server active in this configuration, the IPs have to be set manually:
Once the ethernet cables are plugged in, the eth0 network interface seems to switch from DOWN to UP.
You can check the status using:
ip address show eth0
You can also try to enable it manually:
sudo ip link set dev eth0 up
It then seems to automatically set a link-local address, for me it looks like this:
ip address show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether xx:xx:xx:xx:xx:xx brd ff:ff:ff:ff:ff:ff
inet 169.254.21.183/16 brd 169.254.255.255 scope global noprefixroute eth0
valid_lft forever preferred_lft forever
inet6 fe80::yyyy:yyyy:yyyy:yyyy/64 scope link
valid_lft forever preferred_lft forever
This means the Jetson’s ethernet IP is 169.254.21.183.
IP setup on FC
Now connect to the NuttX shell (using a console, or the MAVLink shell), and check the status of the link:
ifconfig
eth0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx at DOWN
inet addr:0.0.0.0 DRaddr:192.168.0.254 Mask:255.255.255.0
For me it is DOWN at first.
To set it to UP:
ifup eth0
ifup eth0...OK
Now check the config again:
ifconfig
eth0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx at UP
inet addr:0.0.0.0 DRaddr:192.168.0.254 Mask:255.255.255.0
However, it doesn’t have an IP yet. I’m going to set one similar to the one of Jetson:
ifconfig eth0 169.254.21.184
And check it:
ifconfig
eth0 Link encap:Ethernet HWaddr xx:xx:xx:xx:xx:xx at UP
inet addr:169.254.21.184 DRaddr:169.254.21.1 Mask:255.255.255.0
Now the devices should be able to ping each other.
Note that this configuration is ephemeral and will be lost after a reboot, so we’ll need to find a way to configure it statically.
Ping test
First from the Jetson terminal:
ping 169.254.21.184
PING 169.254.21.184 (169.254.21.184) 56(84) bytes of data.
64 bytes from 169.254.21.184: icmp_seq=1 ttl=64 time=0.188 ms
64 bytes from 169.254.21.184: icmp_seq=2 ttl=64 time=0.131 ms
64 bytes from 169.254.21.184: icmp_seq=3 ttl=64 time=0.190 ms
64 bytes from 169.254.21.184: icmp_seq=4 ttl=64 time=0.112 ms
^C
--- 169.254.21.184 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3077ms
rtt min/avg/max/mdev = 0.112/0.155/0.190/0.034 ms
And from the FC in Nuttx Shell:
ping 169.254.21.183
PING 169.254.21.183 56 bytes of data
56 bytes from 169.254.21.183: icmp_seq=0 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=1 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=2 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=3 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=4 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=5 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=6 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=7 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=8 time=0 ms
56 bytes from 169.254.21.183: icmp_seq=9 time=0 ms
10 packets transmitted, 10 received, 0% packet loss, time 10010 ms
MAVLink/MAVSDK test
For this, we need to set the mavlink instance to send traffic to the Jetson’s IP:
For an initial test we can do:
mavlink start -o 14540 -t 169.254.21.183
This will send MAVLink traffic on UDP to port 14540 (the MAVSDK/MAVROS port) to that IP which means MAVSDK can just listen to any UDP arriving at that default port.
To run a MAVSDK example, install mavsdk via pip, and try out an example from MAVSDK-Python/examples.
