LD2410 Rust Driver

A no_std compatible Rust driver for the HLK-LD2410 human presence radar sensor. This library provides a robust interface for communicating with the LD2410 over UART using the vendor's binary framed protocol.

Features

• No-std compatible – works in embedded environments without the standard library
• Robust frame parsing – handles continuous sensor streams with proper header/footer validation
• Normal and engineering modes – read presence data or switch to engineering mode for detailed diagnostics
• Configuration support – enter/exit config mode, read firmware, restart, and more
• Flexible distance parsing – handles firmware variations in distance field encoding

Protocol Overview

The LD2410 communicates via UART at 256000 baud (8N1) using a binary framed protocol:

Sensor Reports (radar → host)

[Header: F4 F3 F2 F1][Length: u16 LE][Frame Data][Footer: F8 F7 F6 F5]

Frame data contains:

• Type byte (0x02 for normal mode, 0x01 for engineering)
• Inner marker (0xAA)
• Payload
• Inner tail (0x55) and check (0x00)

Command/ACK Frames (host ↔ radar)

[Header: FD FC FB FA][Length: u16 LE][Command Word: u16 LE][Payload][Footer: 04 03 02 01]

Usage

Basic Presence Detection

use ld2410::LD2410;

// Create sensor with UART peripheral
let mut sensor = LD2410::new(uart);

// Read presence data continuously
loop {
    match sensor.read_presence() {
        Ok(data) => {
            println!("Presence: {}", data.presence());
            println!("Moving: {}cm (energy: {})", 
                data.moving_distance_cm, 
                data.moving_energy);
            println!("Still: {}cm (energy: {})", 
                data.still_distance_cm, 
                data.still_energy);
        }
        Err(e) => println!("Error: {:?}", e),
    }
}

Configuration

// Enter configuration mode
sensor.enter_config_mode()?;

// Read firmware version
let fw = sensor.read_firmware_raw()?;

// Exit configuration mode
sensor.exit_config_mode()?;

Engineering Mode

// Enable engineering mode for detailed diagnostics
sensor.enable_engineering_mode()?;

// Read engineering reports (type 0x01)
// ... handle engineering data ...

// Return to normal mode
sensor.disable_engineering_mode()?;

Data Structures

PresenceData

Contains the parsed presence detection report:

• target_state – NoTarget, Moving, Stationary, or Both
• moving_distance_cm – distance to moving target
• moving_energy – energy level of moving target (0-255)
• still_distance_cm – distance to stationary target
• still_energy – energy level of stationary target (0-255)
• detection_distance_cm – overall detection distance

Error Types

• Read(E) – UART read error
• Write(E) – UART write error
• InvalidFrame – malformed frame structure
• UnknownReportType – unsupported report type
• InvalidReport – report content too short or inconsistent
• BufferOverflow – received frame exceeds buffer size

Requirements

• UART peripheral implementing embedded-io traits (Read + Write)
• 256000 baud, 8N1 configuration
• Sufficient buffer space (256 bytes internal)

Example

See ../hello-world-ld2410/ for a complete ESP32 example using esp-hal and embassy.

License

MIT