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Overview

The THROW parameter group configures the Throw Mode for multicopters. This specialized mode allows the pilot to literally throw the drone into the air; the autopilot detects the freefall and autonomously stabilizes the vehicle and powers up the motors.

Key Concepts

1. Detection Type (THROW_TYPE)

Determines how the "throw" is identified.

  • Upward Throw: Drone is tossed up.
  • Drop: Drone is released from height.

2. Startup Sequence

  • THROW_MOT_START: Defines when the motors should start spinning (e.g., at the peak of the arc or after a delay).

Parameter Breakdown

  • THROW_NEXTMODE: The flight mode the vehicle automatically switches to after a successful throw stabilization (usually LOITER).
  • THROW_ALT_MIN: Safety altitude floor for activation.

Integration Guide

  1. Arm: Arm the vehicle while holding it.
  2. Switch: Change mode to THROW.
  3. Toss: Throw the drone clear of your body.
  4. Auto-Start: The autopilot will detect the freefall, stabilize level, and then switch to the mode defined in THROW_NEXTMODE.

Developer Notes

  • Library: ArduCopter/mode_throw.cpp.
  • Safety: EXTREMELY DANGEROUS. Only use with small drones and ensure you have a clear area.

THROW_ALT_MAX

m
Default 0
Range 0 500.0

Throw Mode Max Altitude (THROW_ALT_MAX)

Description

THROW_ALT_MAX provides an upper safety boundary for Throw Mode.

This prevents the drone from attempting a launch if it is already at an extreme altitude (e.g., if you are trying to release it from a high-altitude platform and it has already drifted past your safe zone).

  • 0 (Default): Check is disabled.
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THROW_ALT_MIN

m
Default 0
Range 0 50.0

Throw Mode Min Altitude (THROW_ALT_MIN)

Description

THROW_ALT_MIN is a safety filter for Throw Mode.

It prevents the motors from starting if the drone thinks it is too close to the ground. This protects the pilot's hands and the drone if it is accidentally bumped while sitting on the floor.

  • 0 (Default): Check is disabled.
  • Value (m): The drone must be at least this high (e.g. 1.5 meters) before the "Throw" detection logic becomes active.
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THROW_MOT_START

Default 0
Range 0 1

Throw Mode Motor Start Behavior (THROW_MOT_START)

Description

THROW_MOT_START determines if the propellers are spinning while the drone is in your hand.

  • 0: Stopped. The motors remain completely off after arming. They only start spinning once the autopilot detects that you have thrown the drone. This is the Safest for your hands.
  • 1: Spinning. The motors start spinning at MOT_SPIN_MIN as soon as you arm. This ensures the motors are "Ready" and synced, but increases the risk of finger injury during the toss.

Tuning & Behavior

  • Default: 0.
  • Recommendation: Keep at 0 for safety. Only use 1 if your motors or ESCs have trouble starting reliably in free-fall.
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THROW_NEXTMODE

Default 18
Range 0 25

Throw Mode Target Mode (THROW_NEXTMODE)

Description

THROW_NEXTMODE defines what the drone does after it successfully "catches itself" in the air.

  • 18 (Default): Stay in Throw Mode. The drone will hover in place and wait for further commands.
  • 5: Loiter. Transition immediately to GPS-based position hold.
  • 10: Auto. Start the pre-programmed mission immediately after the toss.

Tuning & Behavior

  • Default: 18.
  • Recommendation: Set to 5 (Loiter) if you want the drone to hold its position perfectly after you throw it.
  • Significance: Allows for fully autonomous "toss and go" mission starts.
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THROW_TYPE

Default 0
Range 0 1

Throw Mode Launch Type (THROW_TYPE)

Description

THROW_TYPE defines the initial motion the drone expects when using Throw Mode.

Throw mode allows a pilot to start the drone without using a transmitter or ground station – the drone senses it is "falling" or "flying" and starts its motors automatically to stabilize.

  • 0: Upward Throw. The drone expects to be tossed up into the air. It waits for the peak of the arc (near zero vertical velocity) before starting the motors.
  • 1: Drop. The drone expects to be released from a high point (e.g. from a balloon or a hand held above the head). It starts the motors as soon as it detects free-fall.

Tuning & Behavior

  • Default: 0.
  • Safety: NEVER use Throw mode indoors. Ensure you toss the drone at least 3-5 meters away from you.
View Source
THROTTLE Parameter Group TIMEOUT Parameter Group