Hi-Link HLK-LD2410B-P Human Presence Detection Sensor Module - 24GHz FMCW Radar, GPIO/UART

Unlike PIR sensors that only detect moving heat sources, this 24GHz FMCW radar detects both moving and stationary (micro-moving) humans by analyzing reflected radio waves. It is not affected by ambient temperature, works through thin non-metallic materials, and provides precise distance information, making it superior for reliable occupancy detection.

The module is configured via a UART connection or Bluetooth using Hi-Link's free visual PC configuration tool. You can set the maximum detection distance (up to 5m), define up to 6 sensing zones with individual sensitivity levels, and adjust the 'unoccupied' delay time to tailor performance to your specific environment.

The UART interface outputs structured data packets at a configurable baud rate (default 115200). The data includes the target state (none, moving, stationary), the distance to the detected target (in 0.75m resolution), and the motion energy value. This allows for sophisticated logic and logging in your host controller.

The 24GHz signal can penetrate thin, non-metallic materials like drywall, plastic, or glass, but with significant signal attenuation. Detection through walls is not recommended or reliable. It is designed for line-of-sight or through-enclosure installation within the same room, such as inside a light fixture or behind a plastic panel.

The module requires a stable 5V DC power supply. The GPIO output pin provides a simple high (3.3V) or low (0V) signal to indicate the presence state, compatible with 3.3V and 5V microcontroller logic inputs. Ensure your power source can provide sufficient current for stable radar operation.