Motion sensor with microwave radar RCWL-051

This RCWL-0516 sensor detects every tiny movement. Unlike a PIR module, this sensor can sense through materials such as plastic. This means there is no visible sensor.

The range of this sensor module is approx. 7 meters with an angle of approx. 120 degrees.

The microwave radar motion sensor operates on a voltage of 4V to 28V. Ideal for an ESP32, Arduino or Raspberry Pi project.

The sensor outputs a high signal of 3.3V when motion is detected.

There is also a CDS connection for connecting an LDR so that the sensor only works in the dark.

This motion sensor can be used both independently and in combination with an Arduino or ESP board.

Dimensions
Length: 3.6cm
Width: 1.7cm
Height: 0.08cm

Wiring diagram

Otronic example code for Arduino IDE:
int radarPin = 2;     // Pin to which the RCWL-051 output is connected

void setup() {
  pinMode(radarPin, INPUT);   // Set the radarPin as input
  pinMode(LED_BUILTIN, OUTPUT);    // Set the ledPin as output
  Serial.begin(9600);         // Start serial communication
}

void loop() {
  int radarValue = digitalRead(radarPin);   // Read the value of the radarPin

  if (radarValue == HIGH) {   // If motion is detected
    digitalWrite(LED_BUILTIN, HIGH);   // Turn on the ledPin
    Serial.println("Motion detected!");   // Send a message via the serial monitor
  }
  else {
    digitalWrite(LED_BUILTIN, LOW);   // Turn off the ledPin
  }
}

Explanation of how this code works
The setup() function sets the radarPin as input and the LED_BUILTIN pin as output.
Serial communication is also started with a baud rate of 9600.

In the loop() function, the value of the radarPin is read and stored in the radarValue variable.
If radarValue is equal to HIGH, which means that motion has been detected by the sensor, the built-in LED on the Arduino board is turned on and a message "Motion detected!" is sent via the serial monitor.
If no motion is detected, the LED is turned off.

The code is quite simple and can be adapted and expanded to use the sensor for various applications, such as controlling an alarm system or activating a motor.
Serial communication can be used to send messages to a computer or other devices to signal events or warnings.

The Vin pin is intended for the sensor's supply voltage. In some applications, it may be necessary to supply the sensor with a different voltage than the standard 5V provided via the VCC pin. In that case, the Vin pin can be used to power the sensor with a voltage between 4 and 28 volts.

The CDS pin is intended for connecting a CdS (cadmium sulfide) light-dependent resistor. This resistor can be used to adjust the sensitivity of the RCWL-051. If the CDS pin is not used, it can be connected to the GND pin.

Using the Vin and CDS pins is optional and depends on the specific application for which the RCWL-051 is used. In most applications, the VCC, GND and OUT pins are sufficient for the sensor to function correctly.