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FC Passthrough

Use FC Passthrough when your devices are connected through a flight controller. This method lets you access all devices in the system without disconnecting them.

Supported Devices​

The following ESCs support FC Passthrough:

ESCs (AM32 protocol)

  • KRIOS™ MINI
  • KRIOS™
  • ARES
  • AJAX
  • AJAX HD

When to Use​

  • Devices installed in a vehicle and wired to a flight controller
  • When using Betaflight, Ardupilot, or iNav firmware
  • Accessing multiple devices without physical disconnection

Steps​

  1. Connect the flight controller to your computer with a USB cable.
  2. Click Connect in the top navigation bar.
  3. Select the flight controller's serial port from the list.
  4. Set the connection method to Passthrough.
  5. Select the communication protocol from the available options:
    • AM32 — For AM32-based ESCs
    • Astrata™ — For Astrata-compatible devices
  6. Click Connect.

The Configurator connects to the flight controller first, then enters passthrough mode to communicate with all devices in the system. Each device appears separately — the first is labeled Primary and additional devices are labeled Chained.

ArduPilot Configuration​

ArduPilot requires additional parameter configuration to enable ESC passthrough. Set these parameters using QGroundControl or Mission Planner before connecting.

Motor Mapping​

Set the servo functions to match your motor layout:

SERVO1_FUNCTION 33   # Motor 1
SERVO2_FUNCTION 34   # Motor 2
SERVO3_FUNCTION 35   # Motor 3
SERVO4_FUNCTION 36   # Motor 4
tip

Adjust the motor order to match your specific frame layout.

DShot ESC Setup​

Configure the ESC protocol to DShot:

MOT_PWM_TYPE 6       # DShot600
SERVO_DSHOT_ESC 1    # BLHeli32/Kiss/AM32

For bidirectional DShot (recommended):

SERVO_BLH_BDMASK 15  # Channels 1–4

Enable ESC Passthrough​

SERVO_BLH_AUTO 1     # Enable automatic ESC passthrough
SERVO_BLH_MASK 15    # Channels 1–4 (binary: 1111)
note

SERVO_BLH_MASK value depends on which output channels your ESCs are connected to. Use 15 for channels 1–4, or adjust accordingly (e.g., 3 for channels 1–2).

Flight Controller Panel​

When connected via passthrough, a Flight Controller panel is available on the Device page showing read-only information about the FC:

  • Board name
  • Firmware version
  • Battery status
  • Sensor data

Connecting Multiple Devices​

When using FC Passthrough, all devices connected to the flight controller are detected and listed automatically. You can select any device from the list to view its settings.

Troubleshooting​

IssueSolution
FC Passthrough doesn't find devicesEnsure the flight controller firmware supports passthrough mode and the devices are properly wired.
Connection to flight controller failsVerify the flight controller is not being accessed by another tool simultaneously.
Only some devices appearCheck that all devices are properly wired to the flight controller and powered on.
ArduPilot passthrough doesn't find devicesVerify that SERVO_BLH_AUTO is set to 1 and SERVO_BLH_MASK covers the correct output channels.