mmWave Radar Sensor Arduino-Human Presence Detection Wiki - DFRobot

Introduction

This 24GHz millimeter-wave radar sensor employs FMCW, CW multi-mode modulation and separate transmitter and receiver antenna structure.
In working, the sensor first emits FMCW and CW radio waves to the sensing area. Next, the radio waves, reflected by all targets which are in moving, micro-moving, or extremely weak moving state in the area, are converted into electrical signals by the millimeter-wave MMIC circuit in the sensor system. After that, these signals will be sent to the processor and processed through the related signal and data algorithms. Then, the target information can be solved out.
The millimeter-wave radar can sense the human presence, stationary and moving people within the detection area. Moreover, it can even detect static or stationary human presence such as a sleeping person. There are two ways provided to output detection result: serial port and I/O port switch quantity. Besides that, the sensor module features strong sensing reliability, high sensitivity, small size, easy to be used or embedded in applications.

Features

• Human presence sensing: sense if there is human body in areas
• I/O port switch quantity input and output control
• Serial port input and output control
• Strong anti-interference ability, not to be affected by snow, haze, temperature, humidity, dust, light, noise, etc.

Specification

• 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”

Board Overview

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

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.

Installation

The installation method of millimeter-wave human body sensors is highly sensitive, as improper installation can affect the performance and functionality of the sensor. Common installation methods for this module include top-mounted, bottom-mounted, horizontal, and downward-tilted installations.

1. Top-mounted installation

2. Underneath installation

3. Horizontal installation

Instructions

The module adopts serial communication protocol and uses ASCII code string as command interation and data interaction.

• Serial communication configuration: 115200 baud rate, 1 stop bit, 8 data bits, no parity bit, no flow control
• Command interaction: ASCII code string format, ending with a new line; separated by space between commands to parameters, parameters to parameters.
• When configuring the working parameters of the sensor, the sensor must be in a halted state; after the parameter configuration is completed, a save parameter command must be sent to save the changed parameters in the non-power-loss memory.
• If using this module as a trigger switch, that is, only use the I/O port of the module, and at the same time, when the configuration parameters meet the performance and functional requirements, the serial port is not necessary, and also users do not need to care about the communication protocol.

Output Information Configuration

Description: The default configuration of the sensor is to output the sensing results only in ASCII code string format, and modification is not supported temporarily.

Human body induction result output: ASCII code string format

Description:

• The string information starts with "$" and ends with "*". Multiple parameters are separated by ",", and placeholder parameters(reserved) are replaced by spaces.
• The sensing result of the "Human Sensor" is output at a data refresh rate of 1Hz by default.

Response: $JYBSS,par1,par2,par3,par4*

Sensor Detection Area Configuration

Description:

• The module configures the sensing area as 128 equal parts by default, each equal part is about 15cm. The configuration parameters are selected from 0~127, as the index of the distance value in the sensing area.
• The sensing area allows configuration of 4 segments, the configuration values of the 4 segments must be configured in order from small to large, and cannot contain each other.

Command: detRangeCfg par1 parA_s parA_e parB_s parB_e parC_s parC_e parD_s parD_e

Note: Multiply the start or end value index of the sensing area distance by 15cm, it represents the start or end distance value.

Sensor Output Delay Configuration

Description: configure, when the sensor detects a target, the delay time for the output of the sensing result; after the target disappears, the delay time for the output of the sensing result. By default, when a target detected, the delayed output time is 2.5s; after the target disappears, the delayed output time is 10s.

Command: outputLatency par1 par2 par3

Sensor Start-up Mode Configuration

Description: Configure the sensor to start running immediately after power-on or wait for the start command after power-on. The former is set by default.

Command: sensorCfgStart par1

Sensor Start Control

Description:

**- When the sensor is in an unstarted state and there are no set parameters to be saved, start the sensor to run.

• Through the sensorCfgStart command, when the sensor is configured to start running immediately after power-on, there is no need to execute the sensorStart command to start running.**

Command: sensorStart

Sensor Reset Control

Description: Reset the sensor by software

Command: resetSystem

Sensor Stop Control

Description: Stop the sensor when it is running.

Commands: sensorStop

Configuration Save Parameter

Description: When the sensor parameters are reconfigured through the UART and have not been saved, this command saves the new configuration parameters to the sensor Flash

Command: saveCfg par1 par2 par3 par4

Save the configuration parameters to the non-power-loss memory unit, command: saveCfg 0x45670123 0xCDEF89AB 0x956128C6 0xDF54AC89

Factory reset

Description: Restore the current configuration parameter value of the sensor to the factory default value.

Command: factoryReset par1 par2 par3 par4

Restore configuration parameters to factory default values, command: factoryReset 0x45670123 0xCDEF89AB 0x956128C6 0xDF54AC89

Tutorial for Arduino UNO

Requirements

• Hardware
  • DFRduino UNO R3 (or similar) x 1
  • mmWave Radar x1
  • M-M/F-M/F-F Jumper wires

• Software
  • Arduino IDE
  • Download and install the DFRobot_mmWave Radar Library (About how to install the library?)

API Function List

/**
      @brief Constructor 
      @param Stream  Software serial port interface 
    */
    DFRobot_mmWave_Radar(Stream *s);

    /**
      @brief  Configure sensor detection area  
      @param parA_s The sensing area distance starting value of the first segment, unit: m  
      @param parA_e The sensing area distance ending value of the first segment, unit: m(Must be greater than the starting value of the current sensing area)
    */
    void DetRangeCfg(float parA_s, float parA_e);


    /**
      @brief  Configure sensor detection area 
      @param parA_s The sensing area distance starting value of the first segment, unit: m
      @param parA_e The sensing area distance ending value of the first segment, unit: m(Must greater than the starting value of the current sensing area)
      @param parB_s The sensing area distance starting value of the second segment, unit: m(Must be greater than the ending value of the previous segment sensing area) 
      @param parB_e The sensing area ending value of the second segment, unit: m(Must be greater than the starting value of the current sensing area)
    */
    void DetRangeCfg(float parA_s, float parA_e, float parB_s, float parB_e);


    /**
      @brief  Configure sensor detection area 
      @param parA_s The sensing area distance starting value of the first segment, unit: m
      @param parA_e The sensing area distance ending value of the first segment, unit: m (Must be greater than the starting value of the current sensing area)
      @param parB_s The sensing area distance starting value of the second segment, unit: m(Must be greater than the ending value of the previous segment sensing area)
      @param parB_e The sensing area distance ending value of the second segment, unit: m(Must be greater than the starting value of the current sensing area)
      @param parC_s The sensing area distance starting value of the third segment, unit: m(Must be greater than the ending value of the previous segment sensing area)
      @param parC_e The sensing area distance ending value of the third segment, unit: m(Must be greaer than the starting value of the current sensing area)
    */
    void DetRangeCfg(float parA_s, float parA_e, float parB_s, float parB_e, float parC_s, float parC_e);


    /**
      @brief  Configure sensor detection area 
      @param parA_s The sensing area distance starting value of the first segment, unit: m 
      @param parA_e The sensing area distance ending value of the first segment, unit: m(Must be greater than the starting value of the current sensing area)
      @param parB_s The sensing area distance starting value of the second segment, unit: m(Must be greatet than the ending value of the previous segment sensing area)
      @param parB_e The sensing area distance ending value of the second segment, unit: m(Must be greater than the starting value of the current sensing area)
      @param parC_s The sensing area distance starting value of the third segment, unit: m(Must be greater than the ending value of the previous segment sensing area)
      @param parC_e The sensing area distance ending value of the third segment, unit: m(Must be greater than the starting value of the current sensing area)
      @param parD_s The sensing area distance starting value of the fourth segment, unit: m(Must be greater than the ending value of the previous segment sensing area)
      @param parD_e The sensing area ditance ending value of the fourth segment, unit: m(Must be greater than the starting value of the current sensin area)
    */
    void DetRangeCfg(float parA_s, float parA_e, float parB_s, float parB_e, float parC_s, float parC_e, float parD_s, float parD_e);


    /**
      @brief  Read whether there is people or object moving in the sensing area
      @return  Returning true means that there is people or animal moving in the detection range; false means the opposite
    */
    bool readPresenceDetection(void);


    /**
      @brief  Configure sensor output delay time 
      @param par1 When a target detected, delay the output time of sensing result, range：0~1638.375, unit: s 
      @param par2 When the target disappears, delay the output time of sensing result, range: 0~1638.375, unit: s
    */
    void OutputLatency(float par1, float par2);


    /**
      @brief  Restore the sensor current configuration to the factory settings. 
    */
    void factoryReset(void);

Connection Diagram

Copy the following code to your Arduino IDE and upload it.

Sample Code

/*!
   @file DFRobot_mmWave_Radar.ino
   @ 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. 
   @n 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 oppposite. 
   @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
   @licence     The MIT License (MIT)
   @author [huyujie](yujie.hu@dfrobot.com)
   @version  V1.0
   @date  2020-3-25
   @https://github.com/DFRobot
*/


#include <SoftwareSerial.h>

#include "DFRobot_mmWave_Radar.h"

SoftwareSerial mySerial(3, 2);
DFRobot_mmWave_Radar sensor(&mySerial);

int ledPin = 13;

void setup()
{
  Serial.begin(115200);
  mySerial.begin(115200);
  pinMode(ledPin, OUTPUT);

  sensor.factoryReset();    //Restore to the factory settings 
  sensor.DetRangeCfg(0, 9);    //The detection range is as far as 9m
  sensor.OutputLatency(0, 0);
}

void loop()
{
  int val = sensor.readPresenceDetection();
  digitalWrite(ledPin, val);
  Serial.println(val);
}

Expected Results

Tutorial for FireBeetle ESP32

Requirements

• Hardware
  • FireBeetle ESP32 IoT Microcontroller (or similar) x 1
  • mmWave Radar x1

• Software
  • Arduino IDE
  • Download and install the DFRobot_mmWave Radar Library (About how to install the library?)

Connection

Sample Code

/*!
   @file DFRobot_mmWave_Radar.ino
   @ 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.
   @n 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 oppposite.
   @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
   @licence     The MIT License (MIT)
   @version  V1.0
   @date  2023-3-13
   @https://github.com/DFRobot
*/

#include <DFRobot_mmWave_Radar.h>

HardwareSerial mySerial(1);
DFRobot_mmWave_Radar sensor(&mySerial);


void setup() {
  Serial.begin(115200);
  mySerial.begin(115200, SERIAL_8N1, D2, D3);  //RX,TX
  pinMode(LED_BUILTIN, OUTPUT);

  sensor.factoryReset();     //Restore to the factory settings
  sensor.DetRangeCfg(0, 9);  //The detection range is as far as 9m
  sensor.OutputLatency(0, 0);
}

void loop() {
  int val = sensor.readPresenceDetection();
  digitalWrite(LED_BUILTIN, val);
  Serial.println(val);
}

Result

Print "1" if human presence is detected, otherwise, print "0".

Tutorial for FireBeetle ESP8266

Requirements

• Hardware
  • FireBeetle ESP8266 IoT Microcontroller (or similar) x 1
  • mmWave Radar x1

• Software
  • Arduino IDE
  • Download and install the DFRobot_mmWave Radar Library (About how to install the library?)

Connection

Sample Code

/*!
   @file DFRobot_mmWave_Radar.ino
   @ 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.
   @n 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. 
   @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
   @licence     The MIT License (MIT)
   @version  V1.0
   @date  2023-3-13
   @https://github.com/DFRobot
*/

#include <SoftwareSerial.h>
#include <DFRobot_mmWave_Radar.h>

int LED_BLINK = 2;

SoftwareSerial mySerial(D2, D5);
DFRobot_mmWave_Radar sensor(&mySerial);

void setup() {
  Serial.begin(115200);
  mySerial.begin(115200);
  pinMode(LED_BLINK, OUTPUT);

  sensor.factoryReset();       //Reset to factory settings
  sensor.DetRangeCfg(0, 9);    //Set sensing distance, up to 9m 
  sensor.OutputLatency(0, 0);  //Set output delay 
}

void loop() {
  int val = sensor.readPresenceDetection();
  digitalWrite(LED_BLINK, val);
  Serial.println(val);
  delay(1000);
}

Result

Print "1" if human presence is detected, otherwise, print "0".

Tutorial for FireBeetle ESP32-C3

Requirements

• Hardware
  • Beetle ESP32 - C3 (RISC-V Core Development Board) (or similar) x 1
  • mmWave Radar x1

• Software
  • Arduino IDE
  • Download and install the DFRobot_mmWave Radar Library (About how to install the library?)

Connection

Sample Code

/*!
   @file DFRobot_mmWave_Radar.ino
   @ 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.
   @n 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 oppposite.
   @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
   @licence     The MIT License (MIT)
   @version  V1.0
   @date  2023-3-13
   @https://github.com/DFRobot
*/

#include <DFRobot_mmWave_Radar.h>

HardwareSerial mySerial(1);
DFRobot_mmWave_Radar sensor(&mySerial);

int LED_BLINK = 10;

void setup() {
  Serial.begin(115200);
  mySerial.begin(115200, SERIAL_8N1, 5, 7);  //RX,TX
  pinMode(LED_BLINK, OUTPUT);

  sensor.factoryReset();     //Restore to the factory settings
  sensor.DetRangeCfg(0, 9);  //The detection range is as far as 9m
  sensor.OutputLatency(0, 0);
}

void loop() {
  int val = sensor.readPresenceDetection();
  digitalWrite(LED_BLINK, val);
  Serial.println(val);
}

Result

Print "1" if human presence is detected, otherwise, print "0".

FAQ

If you have any questions about using this product, please check the Human Presence Detection Sensor FAQ【SEN0395】 and Comprehensive Guide to Smart Home Presence Detection ( FAQ )for that product for a corresponding solution.

And for any questions, advice or cool ideas to share, please visit the DFRobot Forum.

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