Thanks Lucas,
Working on a testbed for IP based RF bridge, I built a RPI Zero W2 with the waveshare Ethernet / USB HUB BOX
Here are my notes:
Disable Disable WIFI and Bluetooth to get full speed ttyAMA0
/boot/config.txt
dtoverlay=disable-wifi
dtoverlay=disable-bt
enable_uart=1
/boot/cmdline.txt
remove
console=serial0,115200
leave
console=tty1 root=PARTUUID=f3c0a9b3-02 rootfstype=ext4 fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles
Confirm:
ls -ln /dev
lrwxrwxrwx 1 0 0 7 Nov 19 10:26 serial0 → ttyAMA0
lrwxrwxrwx 1 0 0 5 Nov 19 10:26 serial1 → ttyS0
Building mavlink-router on Pi Zero
Increase swap to 200
limit to 3 threads
ninja -C build -j3
Launch
Set Serial to 921 on FC telemetry
Set correct addressing for GCS
mavlink-routerd -e 192.168.2.237:14550 -e 127.0.0.1:14550 /dev/ttyAMA0:921600