# GPS LED & Buzzer Meaning

### RGB UI LED 

The meaning of the big RGB UI LED depends on the Firmware you use. The definition can be found here:

* [Ardupilot RGB LED Meaning](https://ardupilot.org/copter/docs/common-leds-pixhawk.html#led-buzzer-meanings)
* [PX4 UI RGB LED Meaning](https://docs.px4.io/main/en/getting_started/led_meanings.html#ui-led)

### Other LEDs (Model Dependent)

{% hint style="info" %}
The availability of these LED depends on the GPS Model
{% endhint %}

* **Fix** **(3D Fix)** 
  * Off - No 3D Fixed
  * Blink/Solid On - 3D fixed 
* **RTK (RTK Fix)** 
  * Off -  Not in RTK mode
  * Blink - Float RTK (Blinking is not available in some model)
  * Solid - Fixed RTK
* **GEO** - Used for geofence settings (set through ucenter). This is an user-defined on and off status light, it can be either on or off when the fence conditions are met.
* **PWR** - Always on when the power is normal.
* **ERR (ERROR)** - Lights up when module self-test fails
* **EVT (EVENT)** - LED is off when no eventin. Short blinks indicate there is an event in 
* **LOG Button LED -** LED is ON when the SD card is present or mounted. 

### Buzzer Meaning

* [PX4 Buzzer Meaning](https://docs.px4.io/main/en/getting_started/tunes.html)
* [Ardupilot Buzzer Meaning](https://ardupilot.org/copter/docs/common-buzzer.html)

### Safety Switch (Red LED) 

{% hint style="info" %}
Safety switch is only available in certain model. The safety switch feature is turned off by default in PX4 and some target in Ardupilot.

In Ardupilot, [BRD\_SAFETY\_DEFLT](https://ardupilot.org/copter/docs/parameters.html#brd-safety-deflt) = 0 to disable the safety switch (`BRD_SAFETYENABLE` in older firmware versions).
{% endhint %}

#### Ardupilot firmware ([Wiki](https://ardupilot.org/copter/docs/common-safety-switch-pixhawk.html#led-meaning))

* Constant blinking - system is initialising
* Intermittent fast blinking - system is ready. press the safety switch to enable output to the motors.
* Solid - safety switch has been pressed, motors and servos are able to move once the vehicle is armed.

#### PX4 ([Guide](https://docs.px4.io/master/en/advanced_config/prearm_arm_disarm.html))

* Slow blinking - system is ready. press the safety switch to enable output to the motors.
* Intermittent fast blinking - safety switch has been pressed, motors and servos are able to move once the vehicle is armed.
* Solid – Vehicle is armed