Example Code for Arduino-Get All Sensor Results

Hardware Preparation

• DFRduino Leonardo (SKU:DFR0221)
• C4002 mmWave Motion & Static Presence Module(SKU:SEN0691)

Software Preparation

• Download Arduino IDE Click to download Arduino IDE
• Download the C4002 Library Click to download DFRobot_C4002

Wiring Diagram

Other Preparation Work

• Upload the following code to your Arduino board
• Open the Serial Monitor in Arduino IDE with a baud rate of 115200
• Ensure the sensor is placed in an environment where human presence or motion can be detected

Sample Code

/*!
 * @file getAllResults.ino
 * @brief This is an example to show how to use the DFRobot_C4002 library to get all the results of the C4002 sensor.
 * @copyright	Copyright (c) 2025 DFRobot Co.Ltd (http://www.dfrobot.com)
 * @license The MIT License (MIT)
 * @author JiaLi([email protected])
 * @version V1.0
 * @date 2025-11-04
 * @url https://github.com/DFRobot/DFRobot_C4002
 */
#include "DFRobot_C4002.h"
#if defined(ESP8266) || defined(ARDUINO_AVR_UNO)
SoftwareSerial mySerial(4, 5);
DFRobot_C4002  c4002(&mySerial, 115200);
#elif defined(ESP32)
DFRobot_C4002 c4002(&Serial1, 115200, /*D2*/ D2, /*D3*/ D3);
#else
DFRobot_C4002 c4002(&Serial1, 115200);
#endif

void setup()
{
  Serial.begin(115200);

  // Initialize the C4002 sensor
  while (c4002.begin() != true) {
    Serial.println("C4002 begin failed!");
    delay(1000);
  }
  Serial.println("C4002 begin success!");
  delay(50);

  // Set the run led to off
  if (c4002.setRunLedState(eLedOff)) {
    Serial.println("Set run led success!");
  } else {
    Serial.println("Set run led failed!");
  }
  delay(50);

  // Set the out led to off
  if (c4002.setOutLedState(eLedOff)) {
    Serial.println("Set out led success!");
  } else {
    Serial.println("Set out led failed!");
  }
  delay(50);

  // Set the Resolution mode to 80cm.
  if (c4002.setResolutionMode(eResolution80Cm)) {
    Serial.println("Set resolution mode success!");
  } else {
    Serial.println("Set resolution mode failed!");
  }
  delay(50);
  /**
   * Note:
   * 1. eResolution80Cm: This indicates that the resolution of the "distance gate" is 80cm.
   *  With a resolution of 80 cm, it supports up to 15 distance gates, with a maximum distance of 11.6 meters.
   * 2. eResolution20Cm: This indicates that the resolution of the "distance gate" is 20cm.
   *  With a resolution of 20 cm, it supports up to 25 distance gates, with a maximum distance of 4.9 meters
  */

  // Set the detect range to 0-1100 cm
  uint16_t clostRange = 0;
  uint16_t farRange   = 1100;
  if (c4002.setDetectRange(clostRange, farRange)) {    // Max detect range(0-1100cm)
    Serial.println("Set detect range success!");
  } else {
    Serial.println("Set detect range failed!");
  }
  delay(50);

  // Set the light threshold to 0 lux.range: 0-50 lux
  if (c4002.setLightThresh(0)) {
    Serial.println("Set light threshold success!");
  } else {
    Serial.println("Set light threshold failed!");
  }
  delay(50);

  uint8_t gateState[15] = { C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE, C4002_ENABLE };
  // Resolution mode:eResolution20Cm,This means that the number of 'distance gates' we can operate is 25
  // uint8_t gateState[25] = {C4002_DISABLE,C4002_DISABLE,C4002_ENABLE,...,C4002_ENABLE,C4002_DISABLE};
  if (c4002.configureGate(eMotionDistGate, gateState)) {    // Operation motion distance gate
    Serial.println("Enable motion distance gate success!");
  }
  delay(50);
  if (c4002.configureGate(ePresenceDistGate, gateState)) {    // Operation presence distance gate
    Serial.println("Enable presence distance gate success!");
  }
  delay(50);

  // Set the target disappear delay time to 1s，range: 0-65535s
  if (c4002.setTargetDisappearDelay(1)) {
    Serial.println("Set target disappear delay time success!");
  } else {
    Serial.println("Set target disappear delay time failed!");
  }
  delay(50);

  // Set the report period to 10 * 0.1s = 1s
  if (c4002.setReportPeriod(10)) {
    Serial.println("Set report period success!");
  } else {
    Serial.println("Set report period failed!");
  }
  /* note: Calibration and obtaining all data must have a set cycle */
}

void loop()
{
  // Get all the results of the C4002 sensor,Default loop execution
  sRetResult_t retResult = c4002.getNoteInfo();

  if (retResult.noteType == eResult) {
    Serial.println("------- Get all results --------");
    // get the light intensity
    float light = c4002.getLightIntensity();
    Serial.print("Light: ");
    Serial.print(light);
    Serial.println(" lux");

    // get Target state
    eTargetState_t targetState = c4002.getTargetState();
    Serial.print("Target state: ");
    if (targetState == eNoTarget) {
      Serial.println("No Target");
    } else if (targetState == ePresence) {
      Serial.println("Static Presence");
    } else if (targetState == eMotion) {
      Serial.println("Motion");
    }

    // get presence count down
    uint16_t presenceGateCount = c4002.getPresenceCountDown();
    Serial.print("Presence distance gate count down: ");
    Serial.print(presenceGateCount);
    Serial.println(" s");

    // get Presence distance gate target info
    sPresenceTarget_t presenceTarget = c4002.getPresenceTargetInfo();
    Serial.print("Presence distance: ");
    Serial.print(presenceTarget.distance);
    Serial.println(" m");
    Serial.print("Presence energy: ");
    Serial.println(presenceTarget.energy);

    // get motion distance gate index
    sMotionTarget_t motionTarget = c4002.getMotionTargetInfo();
    Serial.print("Motion distance: ");
    Serial.print(motionTarget.distance);
    Serial.println(" m");
    Serial.print("Motion energy: ");
    Serial.println(motionTarget.energy);
    Serial.print("Motion speed: ");
    Serial.print(motionTarget.speed);
    Serial.println(" m/s");
    Serial.print("Motion direction: ");
    if (motionTarget.direction == eAway) {
      Serial.println("Away!");
    } else if (motionTarget.direction == eNoDirection) {
      Serial.println("No Direction!");
    } else if (motionTarget.direction == eApproaching) {
      Serial.println("Approaching!");
    }
    Serial.println("--------------------------------");
  }
  delay(50);
}

Result