Microwave Motion Sensor (RCWL-0516)

This is an RCWL-0516 microwave sensor, an easy-to-use alternative to the classic PIR sensor we know and love.

Why would you opt for a microwave sensor over PIR? The main reason is its ability to work inside a non-metallic enclosure or even through most walls, allowing you to create something like a room sensor with a clean finish that you’d be happy to have in the home (we have a great little enclosure for that here!). It also means you can use these in garden/outdoors projects, inside a waterproof enclosure.

It’s also much more compact than traditional PIR sensors, and that’s always a good thing!

Using microwave radar technology, this sensor detects motion in a range of 4 to 7 meters, making it ideal for a variety of projects such as human monitoring, pet detection, home automation and more! The output pin is 3.3V, and with an input of 4-28V, you can use this with your Raspberry Pi, Raspberry Pi Pico, Arduino and other similar microcontrollers.

You can even solder a light-dependent resistor (LDR) to the two angled CDS pads to disable the sensor when it detects light – handy for night-only projects, such as garden wildlife (spot those pesky foxes!).

Features

• Microwave radar technology: Uses Doppler radar for motion detection
• Detection range: Effective from 5 to 7 meters
• Wide operating voltage: 4 to 28V DC input range
• 3.3V digital output: Compatible with Raspberry Pi, Pico, Arduino and more!
• High sensitivity: Can detect motion through walls and non-metallic objects
• Compact design: Small form factor allows for easy integration into various projects
• Low power consumption: Efficient design – minimal power usage
• Option to add an LDR: Disables the sensor when it detects light, handy for night-only projects

Specifications

• Operating voltage: 4-28V DC
• Detection distance: ~5-7 meters
• Operating current: ~2.8 mA
• Output: 3.3V
• Dimensions: 36mm x 17mm

Resources

• DroneBot Workshop has a great article on these kinds of sensors

Raspberry Pi Usage

For Raspberry Pi usage (and most microcontrollers) the relevant pins will be:

• VIN – Input voltage (4-28V). Connect this to your 5V line.
• GND – Connect this to a Ground pin
• OUT – Digital output pin, connect this to a GPIO pin as an input

All you need to do then is code your project to look for a HIGH signal on the pin you connected to OUT, the same as any other digital input.

Other Pins

• CDS – Light sensor (LDR) pin, can be used for enable control
• 3V3 – This pin outputs 3.3V (it’s not an input to power the module!) from an onboard regulator, offering 3.3V @ 100mA max

Package Contents

• 1 x RCWL-0516 Microwave Sensor