MAVLINKHUD

Overview

The SAFE parameter group (specifically SAFE_DISARM_PWM) configures the output safety state for the Antenna Tracker.

Key Concepts

1. Disarmed Safety

When the tracker is disarmed or in "Stop" mode, it is important to define what the servos do.

  • SAFE_DISARM_PWM:
    • 0: Zero PWM. Servos are unpowered/limp.
    • 1: Trim PWM. Servos hold their center (neutral) position.

Developer Notes

  • Library: AntennaTracker/Parameters.cpp.

SAFE_DISARM_PWM

Default 0
Range 0 1

PWM that will be output when disarmed or in stop mode (SAFE_DISARM_PWM)

Description

This parameter determines the signal sent to the servos when the Antenna Tracker is in a disarmed state or "Stop" mode. It is a safety feature to ensure the tracker does not move unexpectedly or holds a neutral position when not actively tracking.

The Mathematics

The parameter acts as a selector for the output logic:

  • 0: Zero PWM (Output = 0). Depending on the hardware/HAL, this may mean sending no signal pulses (servos go limp) or sending a 0us pulse width.
  • 1: Trim PWM. The servos are commanded to their trim (center) position.

The Engineer's View

Defined in AntennaTracker/Parameters.cpp and used in tracking.cpp. The values map to the PWMDisarmed enum:

  • ZERO (0)
  • TRIM (1)

Tuning & Behavior

  • Default Value: 0
  • 0 (Zero PWM): Servos are typically unpowered (signal-wise) and can be moved by hand (if digital servos support this) or stay in their last position.
  • 1 (Trim PWM): Servos are actively held at their centered/neutral position.