> For the complete documentation index, see [llms.txt](https://docs.cubepilot.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cubepilot.org/cubepilot-ecosystem/cubepilot-partners/union-robotics/herelink-blue/herelink-blue-user-guide/air-unit/air-unit-leds.md).

# Air Unit LEDs

## LED 1 (left)

|                                  |                                                             |   |
| -------------------------------- | ----------------------------------------------------------- | - |
| Feature                          | Specification                                               |   |
| Steady Green Light:              | Receiving HDMI 1 Signal                                     |   |
| Steady Red Light:                | Receiving HDMI 2 Signal                                     |   |
| Steady Yellow Light:             | Receiving flight control data signal                        |   |
| Changing Green-Yellow-Red Light: | Receiving two video signals and flight controller signal    |   |
| No Light:                        | Receiving no valid video signal or flight controller signal |   |

## LED 2 (right)

|                       |                                                        |
| --------------------- | ------------------------------------------------------ |
| Feature               | Specification                                          |
| Flashing Green Light: | Pairing                                                |
| Steady Green Light:   | Receiving valid controller signal, and power is normal |
| Steady Yellow Light:  | Unpaired/no valid signal received                      |
| Flashing Red Light:   | Unstable power                                         |
| No Light:             | No Light: Rover Unit is not powered                    |

![](/files/gR4cb4WMFeua9mItclah)