How to Use Fermion: C4002 mmWave Human Presence Sensor: Examples, Pinouts, and Specs

The Fermion: C4002 mmWave Human Presence Sensor, manufactured by DFRobot, is a cutting-edge sensor that leverages millimeter-wave (mmWave) technology to detect human presence. By emitting and analyzing reflected mmWave signals, this sensor can accurately determine whether a person is present in its detection range. Unlike traditional motion sensors, the C4002 can detect stationary individuals, making it ideal for advanced applications.

• Smart home automation (e.g., lighting and HVAC control)
• Security systems and intrusion detection
• Energy-efficient office and building management
• Elderly care and health monitoring systems
• Interactive kiosks and touchless interfaces

The Fermion: C4002 mmWave Human Presence Sensor is designed for high precision and reliability. Below are its key technical details:

The sensor has a 4-pin interface for power and communication. Below is the pinout:

1. Power the Sensor: Connect the VCC pin to a 5V DC power source and the GND pin to ground.
2. Connect to a Microcontroller: Use the TX and RX pins to establish UART communication with a microcontroller (e.g., Arduino UNO). Ensure the microcontroller operates at 3.3V logic levels or use a level shifter if necessary.
3. Place the Sensor: Position the sensor in an unobstructed area for optimal detection. The detection range and angle should align with the intended application.

• Avoid Obstructions: Ensure there are no large metallic objects or walls directly in front of the sensor, as these can interfere with mmWave signal reflection.
• Stable Power Supply: Use a stable 5V DC power source to avoid performance issues.
• UART Configuration: Set the UART baud rate to 115200 bps for communication.
• Environmental Factors: The sensor performs best in indoor environments with minimal electromagnetic interference.

Below is an example of how to interface the Fermion: C4002 mmWave Human Presence Sensor with an Arduino UNO:

#include <SoftwareSerial.h>

// Define RX and TX pins for SoftwareSerial
SoftwareSerial mmWaveSerial(10, 11); // RX = Pin 10, TX = Pin 11

void setup() {
  Serial.begin(9600); // Initialize Serial Monitor at 9600 bps
  mmWaveSerial.begin(115200); // Initialize mmWave sensor at 115200 bps

  Serial.println("Fermion: C4002 mmWave Sensor Initialized");
}

void loop() {
  // Check if data is available from the sensor
  if (mmWaveSerial.available()) {
    String sensorData = mmWaveSerial.readString(); // Read sensor data
    Serial.println("Sensor Data: " + sensorData); // Print data to Serial Monitor
  }

  delay(100); // Small delay to avoid flooding the Serial Monitor
}

Note: Connect the sensor's TX pin to Arduino's RX pin (Pin 10) and the sensor's RX pin to Arduino's TX pin (Pin 11). Use a logic level shifter if the Arduino operates at 5V logic.

1. No Data Received from the Sensor

   • Cause: Incorrect UART connection or baud rate mismatch.
   • Solution: Verify the TX and RX connections and ensure the baud rate is set to 115200 bps.

2. Inconsistent Detection

   • Cause: Obstructions or environmental interference.
   • Solution: Ensure the sensor is placed in a clear, unobstructed area and away from strong electromagnetic sources.

3. Sensor Not Powering On

   • Cause: Insufficient or unstable power supply.
   • Solution: Check the power source and ensure it provides a stable 5V DC.

Q: Can the sensor detect multiple people simultaneously?
A: The sensor is optimized for detecting the presence of individuals within its range but does not differentiate between multiple people.

Q: Is the sensor suitable for outdoor use?
A: The sensor is designed for indoor use. Outdoor environments with extreme temperatures or high humidity may affect its performance.

Q: Can the detection range be adjusted?
A: The detection range is fixed, but you can control the sensor's placement and orientation to optimize its coverage.

Q: Does the sensor work in complete darkness?
A: Yes, the mmWave technology is not affected by lighting conditions and works in complete darkness.

This concludes the documentation for the Fermion: C4002 mmWave Human Presence Sensor. For further assistance, refer to the DFRobot support resources.