RCWL-0516 Microwave Proximity Sensor - With & Without Arduino

The RCWL-0516 is an inexpensive proximity sensor that works using microwaves and Doppler Radar. It can be used on its own or with an Arduino, I will show you both ways.

Today we will look at another proximity sensor, the RCWL-0516. This device works using microwaves and the Doppler Effect to detect the presence of humans (and other creatures) in a room. It is inexpensive and can be used by itself or in conjunction with an Arduino.

Don’t be concerned about the microwave aspect, this device emits a very low level of microwave radiation at 3.18 GHz, which is on the low-end of the microwave spectrum. It is perfectly safe to experiment with and to use in your projects.

The device is very inexpensive and can be obtained on eBay, Amazon, and probably at your local electronics shop (which is where I got mine) for around 2-3 US dollars.

The RCWL-0516 operates using the “Doppler Effect”, a phenomenon discovered in 1842 by Austrian physicist Christian Doppler. The Doppler Effect describes a change in frequency observed by a stationary observer when the source of the frequency is moving.

If you have ever heard the sound of a train as it races towards and then away from you, or an ambulance as it races down the road, you will have heard the siren frequency changing as the object approaches, passes, and moves away from you. That is the Doppler Effect in action.

In the RCWL-0515 microwaves are sent out and reflected back. Any moving object in the area will change the frequency of the reflected waves, thus triggering the device.

I will show you how to use the RCWL-0516 on its own, both by itself and with an optional light sensor. You'll see that because it uses microwaves it is still operational even when encased in a plastic enclosure.

Then we will use an Arduino with the RCWL-0516. I’ll show you how to make the device “latch”, great for an intruder alarm or automatic light switch. Then I will show you how I built a remote sensor using an RCWL-0516 and two Arduino's.

Here is the Table of Contents for today's video:

00:00 - Introduction
03:12 - The RCWL-0516 & Doppler Effect
09:33 - Basic Hookup & Demo
12:35 - Light Sensor Hookup & Demo
15:14 - Arduino Latching Device Hookup & Code
20:31 - Arduino Latching Device Demo
23:44 - Arduino Remote - Transmitter Hookup & Code
29:02 - Arduino Remote - Receiver Hookup & Code
32:19 - Arduino Remote Demo

I hope you enjoy the video and the article.

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[jacobdavis]

Just watched your tutorial and set up a new rcwl-0516 as I watched. I bought 20 and the 1st one I tested works very well. It's set up in front of the TV pointing back at me and it is very responsive and stable behavior too. Great channel and tutorial. Thanks!

[KatorNia]

Very good video, with lots of info & well delivered.
I wonder how this channel flew under my radar (pun intended) for so long.
Subscribed! 👍🏻

Now, I have a couple of things I'd like to point out if I may.

8:07 The circular thingy serves as a capacitor for the oscillator (high-frequency NPN transistor), not an antenna.
The antenna is at the other side, & it's a common transmit/receive antenna.

10:44 Although the LED pins are correct (anode = longer), the internal electrodes are wrong (anode = smaller, not bigger).
I'm pointing this out because I believe one should look at the internal electrodes to figure out polarity, instead of the external ones, since the latter can be cut.
& if people learn it wrong from this video, they may run into problems in the future.

20:02 I'd pull the button Pin to LOW, instead of HIGH, for two reasons.
- If you pull it HIGH, you're constantly sinking 0.5mA, regardless of the button's state.
Yes, that current is negligible in this circuit, but I believe it's important to adopt "good habits" anyway.
In the case of microcontrollers, taking their limited power capabilities into consideration is one of them.
- It feels more intuitive to "send a signal" to the Pin when the button is pressed, instead of "disrupting a signal".
I believe it's easier for less experienced tinkerers to understand too.

From what I've read (I haven't tried them myself, yet), those sensors don't interfere with other GHz devices (routers etc).
Apparently they don't interfere with each other either!
So using BT shields should work well too.

[TonySwitzerland]

Perfectly explained! Thank you.
I connected the sensor without Arduino to a "remote doorbell button". Battery operated, small size, can be placed wherever it suits. The bell then rings (or just the LED flashes) when someone enters the controlled zone. Works through walls and doors!

[TonySwitzerland]

Excellent tutorial and because of the clear language 100% understandable by non-native-speakers! Thank you so much.

[vanomso]

Thank you for this lesson. Works very good for me, I invest 35 minutes in watching your video and I remember it forever!

[MadLabZ]

Always the best from DroneBot Workshop!!! I just received five RCWL-0516 modules from aliexpress with intentions of setting up security zones for my property, with this very helpful video I think this will be the start of something very interesting, thanks for the upload.

[acadman]

Thanks, Bill, I am impressed with your clear and professional presentation.

[fsiserir]

Thank you for your very clear explanation of RCWL-0521 and its application for the detection of the moving object.

[johnmcclain]

Hi, this is the first time I've been here, I'm a retired electronics tech, Marines, not played with electronics much for twenty years, but collected some arduino oriented electronics, off ebay, and low and behold, here's how to use the very module I selected for a burglar/security alarm system for my home. Great teaching skills, very clear explanations, nice easy pace. I look forward to getting caught back up, at least as much as necessary. How did you know I bought that doppler radar device?

[yanntwelve]

Hello !! I'm about to prepare myself in making an alarm for my workshop and garage, your video has been more than useful to my future project. Nice explainations and many details. Good Job, keep on instructing us !! Long life to your channel

[jurgenpurps]

Wie immer ein Top-Video.Super und ausführlich erklärt - so sollte es sein.

[satishbalodi]

Sir I am happy to see your tools set is kept. Neet and tidy. Very nice sir.

[ravindrabelsare]

Many thanks ! After watching couple of your earlier workshops, I am practically hooked to it. Every day at least one workshop on my agenda

[donk]

Very interesting and informative video. The RCWL-0516 is now on my list future projects. I also particularly appreciate the care and preparation put into the production, and the use of high quality video. Too often videos like this are made with low resolution video so that the code examples and diagrams are unreadable.

[sno_crash]

I think it's more appropriate to call this a motion sensor, or motion detection module. It has no capability to detect 'proximity'. Any stationary object in the sensors proximity will not be detectable nor can it determine the distance to an object's proximity.

[mohitnayyer]

Thank you very much for explaining everything in detail and for demonstrating the connections.

[RouenEchecs]

Vos vidéos sont très intéressantes et vos explications très claires, avec un réel souci de pédagogie.
En vous suivant, je m'améliore. Je vous remercie très sincèrement pour ce partage.

[dineshmehta]

Sir You are Very good teacher & have very good Knowledge.
Thanks you very much for explaining in simple manner. Keep up teaching and good works.

[ShedOfDreams]

So useful I bought some! Thank you. A good, concise video. I attached the output signal to an optocoupler relay module and the relay switches, so that's good! I've also found that if you keep moving around, the sensor is always active so the relay stays on E.G. running a light bulb, alarm etc. turns off once movement stops. would be good for a self contained alarm/light/ device on its own without needing an Arduino (or Picaxe in my case) so saving a few quid!!!! thank you again, You"ve got a new subscriber :-)

[sebastienochart]

Extremely well explained and demonstrated. Very high quality content. Thanks a lot.