Herelink 1.0 AirUnit to AirUnit instruction
AirUnit HDMI + GroundUnit Ethernet
Device required:
-Airunit x 2 (*firmware minimum 20211229 and above)
-Ethernet adapter
-Installing a fan on both airunits to achieve better performance
https://docs.cubepilot.org/user-guides/herelink/herelink-faq#herelink-airunit-fan-installation
- usb otg+power cable if ethernet adapter doesn't include a method to power it

GroundUnit video out can be accessed via ethernet and MavLink is available as well. Compatible ethernet adapters are shown below:
AX88179 - Ground and Air
UGREEN Ethernet Adapter for Chromecast has an additional standard USB to power on airside, cables are quite long however.
Note:
-Upgrade both units to the latest firmware before toggling the switches.
-Toggle switches both down position as default AirUnit function, firmware only can be upgraded when switches both at down position.
- 1.Upgrade AirUnits to the latest firmware.(Make sure toggle both switches at down position)
- 2.Power off the GroundUnit by disconnecting the power cable (7v-12v).
- 3.Remove the screws from the chassis.
- 4.Herelink AirUnit v1.0 (without ethernet port) Toggle the switches as shown below to activate GroundUnit. (1 up, 2 down) Note: For Herelink AirUnit v1.1 (with ethernet port) GroundUnit activated by toggle switch (1 down, 2up)
- 5.Power on GroundUnit by reconnecting the power cable (7v-12v).

Upgrade AirUnits to latest firmware.(Make sure toggle both switches down position)
Press and hold the pairing button for 3s on both AirUnit and GroundUnit within 30s
*Once pairing is completed LED will turn solid GREEN.

1=Pairing button
2=Indicator Led
Once AirUnit and GroundUnit are paired, connect the 1080p/720p video source to AirUnit.
There are only 1 HDMI port available for communication between AirUnit and GroundUnit, it is marked #3 in the picture below.

1. Please switch off PC’s WIFI
2. Go to control panel > Network & Internet > Network connection
3. Right click and choose properties
4. Choose “internet (TCP/IPv4)”,then click properties
5. Click “use the following IP address” and enter 192.168.144.3”
6. Click “Subnet mask” and it will give you a Subnet mask.

AirUnit video stream can be obtained through VLC, MissionPlanner or QGC
Go to Media > Open Steaming > Communication Protocol
Copy and paste : “rtsp://192.168.144.10:8554/H264Video”
Click “Play”.Click “Play”.

Video
- 1.Right click the HUD
- 2.Select ‘Video’
- 3.Select ‘Set GStreamer Source’
- 4.Enter “rtspsrc location=rtsp://192.168.144.10:8554/H264Video latency=1 udp-reconnect=1 timeout=0 do-retransmission=false ! application/x-rtp ! decodebin3 ! queue max-size-buffers=1 leaky=2 ! videoconvert ! video/x-raw,format=BGRx ! appsink name=outsink”
- 5.Press OK
Mavlink
- 1.Open Mission Planner
- 2.Set the port to 'UDPCL' (top right)
- 3.Click 'Connect'
- 4.Enter the IP 192.168.144.11
- 5.Enter port '14552'
Setup(QGC icon at the top-left corner) > Application Settings > General > Fly View > Video Settings > Source > RTSP Video Stream
RTSP URL “rtsp://192.168.144.10:8554/H264Video”
Go back to the main screen and video input will come out.

VLC latency can be adjusted via below:
Media > Open Network Stream > Network > Click “Show more options” > adjust “caching” time

Tool > Preferences > Input / Codecs > Network > Default caching policy > select “Lowest latency”

Last modified 3mo ago