Connect RCWL-0516 with ESP32 Read Microwave Radar Motion Sensor

This tutorial shows how to use RCWL-0516 microwave radar sensor with ESP32. Unlike PIR sensors that use infrared, RCWL-0516 detects motion by reading changes in reflected microwave signals. This makes it suitable for applications requiring longer detection range.

Required Components

• ESP32 NodeMCU ESP-WROOM-32
• RCWL-0516 Microwave Radar Sensor
• 5mm Red LED x1
• 220 Ohm Resistor
• Breadboard 170 points
• Jumper wires (M-M, M-F, F-F)
• Micro USB cable for upload
• Power Adapter 5V 2A

How RCWL-0516 Works

RCWL-0516 emits microwave signals. When an object moves within range, the reflected wave frequency changes due to Doppler Effect. The sensor detects this change and outputs a signal at the OUT pin.

Key advantages: detection range of 5-9 meters and can detect through thin materials without direct line of sight.

Wiring ESP32 with RCWL-0516

ESP32	Device	Pin
D22	LED (via R220)	Anode
D23	RCWL-0516	OUT
VIN	RCWL-0516	VIN
GND	RCWL-0516	GND
GND	LED	Cathode

Arduino Code for Reading RCWL-0516

// Pin definitions
const int sensorPin = 23;  // RCWL-0516 OUT connected to D23
const int ledPin = 22;     // LED connected to D22

void setup() {
  Serial.begin(115200);
  pinMode(sensorPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.println("RCWL-0516 Motion Detection Ready");
}

void loop() {
  int motionValue = digitalRead(sensorPin);
  
  Serial.print("Sensor Value: ");
  Serial.println(motionValue);
  
  digitalWrite(ledPin, motionValue);
  
  delay(100);
}

Upload Steps

1. Open Arduino IDE and paste the code above
2. Go to Tools -> Port and select ESP32 port
3. Go to Tools -> Board and select ESP32 board type
4. Click Upload button
5. If “Connecting…” appears during upload, hold BOOT button on the board
6. Wait for “Hard resetting via RTS pin…” to confirm success

Expected Results

Open Serial Monitor at Baud Rate 115200 and observe the values:

• No motion → Sensor outputs 0, LED off
• Motion detected → Sensor outputs 1, LED on
• Motion stops → Sensor continues briefly before returning to 0

Customization Points

To make LED blink when motion is detected, add blinking logic in the loop section when motionValue equals 1 using short delay intervals.

Reference Video

• https://www.youtube.com/embed/tTdLUZilIzY