Skip to main content

LED Agent

This document describes the LED controller daemon that runs on Puma hardware.


When envParams.LED_AGENT_ENABLED is set in the node configuration, the led-agent daemon will run and control the three green LED lights beneath Puma units using GPIO pins (/sys/class/gpio).

The behavior of the LEDs is as follows:

LEDGPIOPossible States
  • ON: The node is powered on (specifically, led-agent is running).
  • ON: At least one link is associated.
  • OFF: No links are associated.
  • ON: All links are of good RF quality.
  • BLINK: At least one link exhibits poor RF quality.
  • OFF: No links are associated, or RF quality could not be determined.

Link quality is determined by the MCS reported via firmware stats. A "good" link must be operating at MCS 9 or higher.

led-agent subscribes to stats published by driver-if to obtain link quality data.