External LEDs

This article shows how to connect external LEDs.

External LED for Pixhawk

An external Pixhawk LED can be added by connecting it to the Pixhawk’s I2C port. Because most users use an Ublox GPS and Compass module, an I2C splitter is recommended. Once connected the similar LED on the center of the Pixhawk will no longer light up.

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Two External LED solutions for APM2 (Copter only)

There are two recommended solutions for adding LEDs.

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If you choose to control the pins directly from the APM, you must choose LEDs which have a current draw lower than the maximum permissible current of the AVR chip on the APM: 40mA.

For AC3.1.5, the pinout of the APM is as follows:

  • A4 : AUX led
  • A5 : Beeper - can drive a piezo buzzer directly (see below)
  • A6 : GPS - will flash with no GPS lock, solid with GPS lock
  • A7 ~ A11 : Motor LEDs

Which LEDs are active and when they blink is somewhat configurable through the LED_MODE parameter which can be set from the Mission Planner’s CONFIG/TUNING > Standard Params > Copter LED Mode drop down.

For AC3.2, the LED_MODE parameter is removed but all the following reduced set of pins are always active:

  • A4 : Motor LED
  • A5 : Beeper - can drive a piezo buzzer directly (see below)
  • A6 : GPS - will flash with no GPS lock, solid with GPS lock
  • A7: Arming LED