INAV Remote Controller and Throttle Control

I. Remote Control Commands

Arming
When the aircraft is armed, it means the aircraft is ready to fly, and when throttle is applied, the motors will start to spin. For multirotor aircraft, motors will spin at a low speed by default when armed (this feature can be disabled by setting MOTOR_STOP, but it is not recommended for safety reasons).
However, for fixed-wing aircraft, this feature needs to be disabled to prevent injury from motor spinning when throttle is unlocked.
Arming and disarming operations are performed through a switch set on the mode page.
Yaw Stick Arming Override
When navigation mode is configured and GPS lock is not obtained, or when a waypoint mission is loaded but the first waypoint is farther than the set distance, arming will be disabled. If you need to bypass this arming limitation, you can do so by setting nav_wp_safe_distance to ALLOW_BYPASS and moving the yaw stick to a high position when using the arming switch. This will bypass the GPS arming limitation before INAV 4.0.0, as well as the GPS and "first waypoint too far" arming limitations after INAV 4.0.0.
Diagram of using the RC transmitter to control the command stick:

II. Throttle Settings and Their Interactions

In the flight controller system, throttle settings are critical for controlling aircraft stability and safety. Different throttle settings interact to ensure the aircraft can arm, fly, and disarm properly. Below are detailed explanations of throttle settings and their interactions:
Related Throttle Settings:

1. throttle_idle
   This setting is typically the minimum throttle value that ensures all motors can start stably. It represents the aircraft's idle throttle level, usually set above the minimum throttle position where motors can start reliably. When motor stop is enabled, motors will spin at this throttle value.
   When armed, if the motor stop function is disabled, motors will continue to spin at this setting, so safety must be considered to ensure motors do not start spinning unintentionally.
   2. min_check
   This is the minimum throttle threshold for the aircraft on the ground. When throttle is below this value, the flight controller will take appropriate action (such as motor stop or keeping throttle at minimum).
   In different arming modes, min_check has different effects:

• When using switch arming mode, throttle below min_check will cause motors to spin at min_throttle speed.
• If using the default stick arming mode, when throttle is below min_check, motors will spin at min_throttle and yaw control will be disabled to allow for arming/disarming operations.
• When motor stop is enabled, throttle below min_check will cause motors to shut down and send min_command to the ESCs.
  The min_check setting must be very precise to ensure aircraft safety. If set too low, the aircraft may not stop correctly or may not be able to disarm.
  3. min_command
  This setting is the minimum command value sent to the ESCs when throttle is below min_check or the aircraft is not armed. It ensures that when the aircraft is not armed, the ESCs receive a valid command to stop motors (if motor stop is enabled). It needs to be set lower than the minimum value required for motor startup to ensure safety when motors stop.
  4. max_check
  When throttle exceeds the max_check setting, the flight controller will send max_command to the ESCs, which is the maximum throttle command. It is used to limit the aircraft's maximum throttle output to prevent motors from exceeding their intended operating range.
  5. max_throttle
  This is the maximum throttle command value sent from the flight controller system to the ESCs. It defines the maximum throttle output the aircraft can achieve, typically used to control the aircraft's maximum thrust.
  Interactions Between Throttle Settings:
• Throttle below min_check: In this case, the flight controller will ensure motors stop or run at minimum speed. If motor stop is enabled, motors will stop and send min_command. If motor stop is not enabled, motors will run at min_throttle speed until throttle exceeds min_check.
• Throttle above max_check: When throttle exceeds max_check, the flight controller will send max_command to the ESCs to ensure the aircraft does not lose control when throttle is too high.
• Accuracy of throttle value settings: Ensure min_check and throttle_idle are set correctly and match the flight controller's expected operating range to provide aircraft stability. Setting min_check too low may prevent the aircraft from disarming safely, while setting max_check too high may cause excessive thrust, affecting control.
  In summary, throttle settings need to be configured with great care to ensure the aircraft operates properly in different modes and maximizes safety.

III. Yaw Control Explanation

When you use the sticks to perform arming/disarming operations, the yaw channel stick is typically moved to its extreme position (for example, full left). To prevent the aircraft from yawing behavior on the ground due to yaw signal input during arming, by default, when throttle is low (below the min_check setting value), yaw input will not cause the flight controller to output yaw control.
Special Instructions:
For tri-copter users, you may want to test if the tail servo is working properly at low throttle on the ground (for example, checking if it correctly responds to yaw input). In this case, you can set tri_unarmed_servo = 1 (default value) in the CLI, so that even before arming, you can control the tail servo to respond to the yaw channel.

• If you are concerned about the tail servo touching the ground or being obstructed on the ground, you can set this parameter to tri_unarmed_servo = 0, which disables yaw output on the ground.
  | tri_unarmed_servo value | Yaw control allowed? | Before arming + low throttle | Before arming + normal throttle | After arming + low throttle | After arming + normal throttle |
  | --- | --- | --- | --- | --- | --- |
  | = 0 (disabled) | No | ❌ | ❌ | ❌ | ✅ |
  | = 1 (enabled, default) | Yes | ✅ | ✅ | ✅ | ✅ |
  ————This article is referenced from the INAV official website: https://github.com/iNavFlight/inav/blob/master/docs/Controls.md