Overview

The BACKEND parameter group (specifically BACKEND_TYPE) configures the AP_Logger storage destinations. In the full parameter list, this is usually seen as LOG_BACKEND_TYPE.

Key Concepts

DataFlash Logging

ArduPilot records high-frequency flight data (IMU, EKF, GPS, Motors) to a "DataFlash" log (.BIN file). This log is essential for post-flight analysis and tuning.

Backend Types

• File (1): Standard SD Card logging.
• MAVLink (2): Streams log data over the MAVLink telemetry link to the GCS (requires high bandwidth).
• Block (4): Logs to onboard SPI Flash memory (common on smaller boards without SD slots).

Parameter Breakdown

• BACKEND_TYPE: Bitmask of active logging destinations.

Integration Guide

• Standard: Set to 1 (File) for most Pixhawk-class controllers.
• No SD Card: Set to 4 (Block) if your board uses internal flash.