> For the complete documentation index, see [llms.txt](https://docs.nwblue.com/nw-blue/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nwblue.com/nw-blue/products/radio-controllers/herelink-blue/user-guide/herelink-blue-1.0-air-unit-to-air-unit-instructions.md). # Herelink Blue 1.0 Air Unit to Air Unit Instructions ### Device Required \ -Air unit x 2 (**\*firmware minimum 20211229 and above**)\ -Ethernet adapter\ -Installing a fan on both air units to achieve better performance\ \- usb otg + power cable if ethernet adapter doesn't include a method to power it ![](/files/z5gsDJGonmynZbExcal9) Ground station unit video out can be accessed via ethernet and MavLink is available as well. Compatible ethernet adapters are shown below: AX88772 - Ground (not tested Airside) [PLUGABLE](https://plugable.com/products/usb2-otge100/) - directly connect to OTG. Nice for the ground side. AX88179 - Ground and Air [UGREEN Ethernet Adapter for Chromecast](https://www.amazon.co.uk/UGREEN-Ethernet-Adaptor-Chromecast-Network/dp/B01N1X28F1/ref=asc_df_B01N1X28F1/?tag=googshopuk-21\&linkCode=df0\&hvadid=309964054975\&hvpos=\&hvnetw=g\&hvrand=13338390534555592071\&hvpone=\&hvptwo=\&hvqmt=\&hvdev=c\&hvdvcmdl=\&hvlocint=\&hvlocphy=9045387\&hvtargid=pla-303357944812\&psc=1) has an additional standard USB to power on airside, cables are quite long however. R8152 / R8153 - Airside only [Cable Matters](https://www.amazon.co.uk/gp/product/B00ET4KHJ2/ref=ppx_yo_dt_b_asin_title_o04_s01?ie=UTF8\&psc=1)​​[Anker USB 3.0](https://www.amazon.co.uk/gp/product/B00NPJP33M/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8\&psc=1) - no blinky lights on the Ethernet port, maybe annoying for debugging **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. Ground Unit and Air Unit Setup ### 1A GroundUnit setup 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. Toggle the switches as shown below to activate GroundUnit. (1 up, 2 down) 5. Power on GroundUnit by reconnecting the power cable (7v-12v). ![](/files/KzNTdGsuE313aqjvZk91) ### **1B Air Unit setup** Upgrade Air Units to latest firmware.(Make sure toggle both switches down position) ## **2. Pairing** Press and hold the pairing button for 3s on both AirUnit and GroundUnit within 30s \*Once pairing is completed LED will turn solid GREEN. ![](/files/YNDi6lhS8wh5mGqXynEq) ## 3. AirUnit HDMI functionality 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. ![](/files/AqUrv6KakoUCy9o0sxid) ## 4. PC setup 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. ![](/files/QgvO9TdTrAaDlp4pdlSk) ## 5. PC video setup AirUnit video stream can be obtained through VLC, MissionPlanner or QGC ### 5A VLC setup Go to Media > Open Steaming > Communication Protocol Copy and paste : “rtsp\://192.168.144.10:8554/H264Video” Click “Play”.Click “Play”. ![](/files/GgGOQ4bTuD1QeavvF5Lw) ### 5B Mission Planner **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' ### **5C QGC** 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. ![](/files/ADOCmPBtPhBiIk8Os3Yd) ## 6. VLC Video Latency Setup \ VLC latency can be adjusted via below: Media > Open Network Stream > Network > Click “Show more options” > adjust “caching” time ![](/files/l3Psq0NaTiHJEPwvW9DU) Tool > Preferences > Input / Codecs > Network > Default caching policy > select “Lowest latency” ![](/files/Yx7v9nDHH4rmztEXhXt7)