CommunityForumWikiBlogLearn
Sensors
Motion Sensors

24GHz mmWave Human Presence Detection Sensor

SKU: SEN0395

This 24GHz mmWave radar sensor uses FMCW/CW multi-mode modulation and separate Tx/Rx antennas. It detects moving, micro-moving, or stationary humans (e.g., sleeping people) by emitting waves, converting reflections to signals, processing via algorithms, and solving target info. Outputs are via serial port or I/O switch. Features: high reliability, sensitivity, small size, easy to use/embed.

Front of mmWave radar module for human presence detection with LED indicators-DFRobot product sku:SEN0395 image.

Downloadable Resources

  • Docs
  • Tech Specs
  • Projects
  • Blog
    • 1. Getting Started

    This guide provides detailed instructions on installing millimeter-wave human body sensors, covering top, bottom, horizontal, and downward-tilted methods to ensure optimal sensor performance.
    2. Example Code for Arduino UNO-Human Presence Detection

    Read whether there is people or object moving in the detection range of the sensor. The sensor detection range and output delay time can be configured. Also you can restore the sensor to factory default settings. Experimental phenomenon: When the sensor starts successfully, 0 or 1 will be printed on the serial monitor. 0 means that there is no human or object moving in sensing area, 1 means the opposite.
    3. Example Code for FireBeetle ESP32-Human Presence Detection

    The article offers a comprehensive guide on implementing human presence detection using FireBeetle ESP32 and mmWave Radar, detailing hardware and software preparation, wiring diagrams, and sample code for effective motion detection.
    4. Example Code for FireBeetle ESP32-C3-Human Presence Detection

    This article guides you through setting up the FireBeetle ESP32-C3 with mmWave Radar for human presence detection, including hardware and software preparation, wiring instructions, and sample code for effective detection.
    5. Example Code for FireBeetle ESP8266-Human Presence Detection

    Detect if there is object or human motion in measuring range; Allows for configuring sensing area, sensor output delay, and resetting sensor to factory settings. Experimental phenomenon: When the sensor is enabled, print 0 or 1 on the serial port: 0 for no motion detected in the sensing area, 1 for object/human movement detected.
    Reference

    Specification

    Parameter Value
    Power Supply 3.6~5V
    Operating Current 90mA
    Detection Distance 9m
    Equivalent Transmit Power 13-15dBM
    Beam Angle 100×40°
    Modulation Mode FMCW, CW
    Operating Frequency 24GHz
    Operating Temperature -40~85℃
    Buad Rate 115200
    Dimension 24×28mm/0.94×1.10”

    Pinout

    The interface definition and function description of this millimeter wave are shown in Table 1.

    Num Label Description
    1 UART Tx Sensor UART Transmiting
    2 UART Rx Sensor UART Receiving
    3 GPIO1 Universal Input and Output
    4 GPIO2 Universal Input and Output(By default, it outputs high when people presence detected, otherwise, output low)
    5 GND Ground
    6 VCC Power +
    7 NC Reserved, left floating
    8 NC Reserved, left floating

    The two I/O ports can be used for level trigger input and output applications; The 1 UART port can used to configure input and sense result.

    FAQ

    • What should I pay attention to when installing this mmWave Radar - 24GHz Human Presence Detection Sensor（SEN0395）?

      Pay attention to the beam angle in the wiki page, the beam angle faces the detected problem, the antenna of the sensor faces the measured object, and the recommended beam angle: 100*40° (width*height).

    • What is the output of this sensor (SKU: SEN0395)? Do I need an external pull-down resistor for output?

      Supports GPIO output, supports serial port output, and does not need pull-down resistors when outputting, and can be directly connected to the main control board.

    • Can this mmWave radar sensor (SKU: SEN0395) only detect human body?

      No, the sensor detects movement of all objects within range by detecting mmWave radar and is very sensitive.

    • Why is the output of my mmWave Radar - 24GHz Human Presence Detection Sensor (SKU: SEN0395) always 1?

      1. Due to the high sensitivity of this millimeter-wave radar sensor, please ensure that the sensor is fixed firmly when using it. When holding it, the sensor will continuously output high level due to slight shaking.

      2. Please try to change the sensor measurement range in the code or serial port settings, and make sure that there is no object moving within the range, and check whether the sensor value returns to normal.

    • Can this millimeter-wave radar sensor (SKU: SEN0395) be used through walls?

      Our tutorial reveals a certain degree of penetrability for wood. However, the properties of electromagnetic waves dictate that the higher the frequency, the weaker its ability to penetrate through walls. Therefore, the 24 GHz mmWave possesses a certain degree of wall-penetrating ability, albeit not particularly strong. It is recommended to avoid thick obstructions as much as possible when using it.

    Explore More Related Questions >

    Was this article helpful?

    TOP