Arduino(11): RCWL-0516 microwave radar sensor switch module

Recently I saw a Microwave Radar Sensor Switch: RCWL-0516. The shape looks different from the traditional infrared sensor. If you want to detect the movement of an object, you don’t know the effect. Buy one and test it out.

RCWL-0516 is a Doppler radar microwave motion sensor module, which can be used as a substitute for PIR motion sensor. The most commonly seen application is the application of automatic flushing in men's toilets. When a person approaches, it automatically flushes a small amount of water; when leaving, it automatically flushes a larger amount of water, and then automatically stops. These are the applications of induction modules. Others are also used to inform visitors, turn on the light switch inductively, and so on.

The following are several human sensors that I have bought from the past to the present. From left to right, they are HC-SR501, HC-SR505 and RCWL-0516. The first two use the principle of infrared sensing to detect the movement of objects. , The latter is the way of using microwave radar, the following will use the same program to test the results of the reaction.

[HC-SR501] (left side of the picture)

This sensing module is also called Passive InfraRed Sensors (PIR) or PIR Motion Sensor, which is an electronic device that uses infrared to detect the movement of objects. Product features:

Working voltage: DC5V to 20V
Static power consumption: 65 microamps
Level output: high 3.3V, low 0V
Delay time: adjustable (0.3 seconds to 18 seconds)
Blocking time : 0.2 seconds
Trigger mode: L can not be repeated, H can be repeated, the default value is H
Sensing range: less than 120 degrees cone angle, within 7 meters
Working temperature: -15~+70 degrees

[HC-SR505](center of the picture)

This module is also called "mini human body sensor module", and it is also an automatic control product using infrared technology.

Product features:

Working voltage range: DC4.5V-20V
Sensing angle: <100 degrees cone angle
Sensing distance: within 3 meters
Output voltage: high 3.3V / low 0V
Working temperature: -20 – +80 degrees
Sensor lens size: diameter: 10 mm (default)

[RCWL-0516] (right side of the picture)

RCWL-0516 is a Doppler radar microwave motion sensor module, which can be used as a substitute for PIR motion sensor. Product features:

Working voltage: DC4V～28V
Output voltage: DC3.3V
Induction distance: 5～7 meters

PIN pin description:

3V3: can output DC3.3V, drive current 100mA
GND: Connect to GND
OUT: output a high potential when an object moving in the detection area is detected
Vin: working voltage: DC4V～28V
CDS: OUT continues to output a low potential when the trigger control is less than 0.7V, if connected to a photoresistor Detection can be turned off at night

[Material]

Arduino UNO or Leonardo x 1
RWCL-0516 / HC-SR501 / HC-SR505 module each 1
LED x 1
Breadboard x 1
Connection wires x N

[Wiring diagram]

Connect the long LED pin to Pin 3, and connect the other pin to GND.
The pins of RWCL-0516 / HC-SR501 / HC-SR505 are GND and VIN to Arduino's GND and 3.3V, and OUT to Pin 8.

RWCL-0516/HC-SR501/HC-SR505	Arduino
3V3	-
GND	GND
OUT	Pin 8
VIN	5V
CDS	-

[Code]

const int pinSensor = 8;
const int pinLed = 3;
int ismotion;
 
void setup() {
  Serial.begin(9600); 
  pinMode (pinSensor, INPUT); //define sensor
  pinMode (pinLed, OUTPUT);   //define LED
}
void loop() {
  ismotion = digitalRead(pinoSensor);  // read data from sensor
  if(ismotion == 1){                   // Start
    digitalWrite(pinLed,HIGH);         // Led on
    Serial.println("Detectived");    
  }
  else{
    noTone(pinLed); 
    Serial.println("Not Detectived"); 
  }
}

[Result]

Connect the three sensing modules RWCL-0516 / HC-SR501 / HC-SR505 to the Arduino. After connecting to the power supply, the sensitivity is RWCL-0516. The other two, if you want to distinguish between high and low, use HC -SR505 is better.
RWCL-0516 will automatically cancel the detection after stopping for a short period of time (refer to the video), but for the other two, sometimes it takes a long time for the signal to be cancelled.
When tested at a specific distance, the sensitivity is still RWCL-0516. This test did not measure the farthest distance of the three sensors. I believe it should be the RWCL-0516, which is induced by microwave radar.