#135

[@AndreasSpiess]

As many commenters rightly found out, these devices are regenerative receivers. If you are interested in "real" radar sensors, I propose watching video #439

[@andrewainger]

If these devices are regenerative RECEIVERS do they need a licence? After all, they do actually radiate! thanks

[@AndreasSpiess]

@@andrewainger I do not think a license would help here. They are anyway illegal...

[@waltsteinchen]

Today my RCWL-0516 's arrived from ali-express, could'nt wait to do some experiments .. (did'nt add any additional components) Wow .. these things are unbelievable sensitive especially moving to or away from them. Over the entire distance of my buro (~4 Meter) a movement of 2 cm's of my hand is enough to trigger it. Thanks a lot Andreas for making this great video!

[@AndreasSpiess]

You are right. Most of the time, I think, we have to reduce sensitivity rather than to try to increase it...

[@richardroy6747]

They are really too sensitive. I tried connecting one(rcwl-0516) to a nodered counter node via a 8266 microcontroller to detect the number of detections and found that even with nobody present in the apartment it is still detecting movement at times.I live in an apartment building so I assume it is detecting movement through the walls in the other apartments.I did not try to reduce the sensitivity yet. Has anybody tried it with resistors to reduce sensitivity?

[@voltlog]

excellent comparison video, I can see allot of work went into making this.

[@AndreasSpiess]

Thanks!

[@yorickhunt3371]

Lucky for him that his neighbour works as a ground controller at the local airport, so he's an expert at flapping his arms around :-P

[@KetilDuna]

Mystery gadgets! Nice writeup. You have a very comfortable voice and clear, easy to understand diction. Good job!

[@AndreasSpiess]

Thanks!

[@migoffmig]

Ketil Duna , Really good diction, I'm from Russia and I understood all the information. Good work!

[@dishendra.]

Sir your videos are gold, it reflects how much work you put into these masterpiece review videos.

[@AndreasSpiess]

Thank you!

[@AbqMichaelMcDonald]

I have been using RCWL-0516 Microwave Radar Sensors in a smart lighting application (integrated with ESP32 developer boards) for several months now. To this video I would add a couple notes. The first is that though the sensors do not interfere with each other, they can get false triggered from the ESP32. This effect falls off after a centimeter or two. Lesson learned, be careful mounting the sensors to the same circuit board as your controller. The lack of directionality and ability to penetrate wood is amazing and perfect for my application. The sensors often detect me just before I enter the rooms with my lights. My sensors appear to work through regular glass. I mounted some of my smart lights on my double pane window and the detectors see me from outside my house. My different experience may be explained by the sensors penetrating the wood but it may be that I’m using traditional glass and your video reported testing against acrylic glass. The later makes sense as acrylic would act more like water than silicate. A final note on voltages... Though it does take 5V to power the sensors, the sensor output voltage is 3.2-3.4V. This is perfect if you’re powering your circuit with a 5V supply and reading the signal with a CMOS device like the ESP32.

[@AndreasSpiess]

Thank you for your additions!

[@atharavkarandikar5289]

Will it be able to detect u if ur are not moving or sleeping

[@Dronebotworkshop]

Thank you so much for doing this, prior to this video I was not aware of these cheap radar sensors (the rcwl-0516 is on eBay for about a dollar). As usual your testing was detailed and your explanation was perfect. Another excellent video!

[@AndreasSpiess]

Thank you for your nice words!

[@PaulJaros]

Hi. I've recently discovered the RCWL-0516 and in search of more specifics I've then found your video.Your extensive tests are very helpful. Especially the needed voltage to run it, the diagnosis if the devices interfere with each other, the directionality and what they penetrate. Viele Grüsse aus dem Hackerspace Ruum42 aus der Ostschweiz.

[@ralfjahns3777]

The long awaited radar sensor comparision you promised to do! You have not forgotten it! Now I know these devices work and which one to buy. Thank you so much!

[@AndreasSpiess]

You are welcome!

[@PhG1961]

I keep repeating myself... great video ! A very good comparison which is very usefull. It will defenately help me for choosing the right one. Thanks Andreas !

[@AndreasSpiess]

You are welcome!

[@Absolutelyautomation]

I discovered those modules recently, and still waiting for them to arrive. You saved me a lot of time, i don't have to make a comparative test. Thank you

[@AndreasSpiess]

You are welcome!

[@edwardrf]

First of all, great video! These motion detection radars most likely works in doppler mode, which is sensitive to frequency close to its emitting frequency, which explains why 2 of the same model do not interfere with each other, and why they don't detect stationary object.

[@AndreasSpiess]

You are probably right. There are a few ideas around in the comments. I do not know what is right or wrong...

[@samuelwels2524]

Super Vergleich! :) Die Neugier auf die Module ist geweckt und alle wichtigen Fragen sind in einem Video beantwortet! Klasse Arbeit!

[@AndreasSpiess]

Danke!

[@Peter_S_]

Perfect timing! I just received four RCWL-0516 units. I could not decide which variety to get and it appears randomness intervened to select a good choice for me. These evaluations of similar products are both interesting and useful. Thank you!

[@AndreasSpiess]

You are welcome!

[@BikerCaf]

Very good, thank you. You have to bare in mind that a lot of double glazing windows have an aluminium coating all over the glass for thermal insulation/reflection, and so this will no doubt explain away a lot of the RF attenuation you found when doing the double glazing window through tests.

[@AndreasSpiess]

Maybe it has a coating. But I do not think so. It is more than 20 years old and back then, coating was quite expensive.

[@UberAlphaSirus]

IRC these units don't work like a radar. IRC they don't receive a signal back from what they send out. They just emit a continuous wave and monitor how much power it is using to transmit. if something moves in it's "field" it changes the SWR standing wave ratio of the transmitter, causing it to us more or less power that the comparitor uses to cause a trip.

[@AndreasSpiess]

This is one additional opinion on how these devices work. I stopped to try to understand. I just use them...

[@UberAlphaSirus]

Baaaa

[@keesterwee4890]

I agree with Sirus. This is very similar to the way shop lifting alarms work.

[@atmel9077]

Depending of the distance between the transmitter and the reflections the signal arrives at the receiver either in phase, out of phase or in betwee at the receiver. The two signals are present on the transistor at the same time. As the transistor is a nonlinear device the two signals mix together and generate a DC offset dependant of their relative phase. When an object is moving in front of the sensor this DC offset oscillates at a very low frequency. This signal is amplified and detected by a chip which is very similar to the BISS0001 used in PIR sensors as the output signals of these sensors are nearly identical. The only difference is that this chip includes a built in 3.3v regulator.

[@TRS-Tech]

@@keesterwee4890 They do not work the same way as the shop theft systems. They rely on the same technology used with prox or access control tags. The arches transmit an rf signal that sweeps a small bandwidth at around the 3.8ghz mark. The tags on the shop item have an antenna tuned to that frequency, a small capacitor and transistor in a smc package connect to the antenna. The RF energy from the arches powers the IC in the alarm tag and creates a simple oscillation resulting in a reflection of RF power at a slightly offset frequency or delay depending on the system type. The signal return to the arch triggers the alarm. It's just come over to the uk but stores in Japan have been using this for years with IC's that will return a pulsed code instead of just a "present" signal as with the theft alarms. These shops in Japan allow you to swipe your customer card and then go round the store filling your trolly. When you exit the store all the prox codes are read and you are billed for the goods. Sadly until all the packaging manufacturers and the industry incorporate smart IC technology we cannot switch to this system. I tested a product with a smart tag a while back and was not surprised to discover that the coded return from the product matched the bar code ! I assume this has been done to make life easier for any stores that have a barcode database. They only then need switch from a barcode reader to an RF based one. I can't see unmanned stores taking of in the UK just the stock itself ;-) With regards to how these little detectors do operate see my reply to "Sirus"

[@dougmanatt4317]

Thanks for checking out these various sensors. I think I will find them very useful and it is great to be able to rely on you to sort the features of the many choices available!

[@AndreasSpiess]

You are welcome!

[@raymondvanrykel3384]

Andreas, The working principle of these type of radars (radio detection and ranging) is well understood and used in many applications already for many years. In a nutshell: These radars typically work in the L to X band : 1GHz-12.5GHz They are frequency modulated continuous waves radars typically with linear frequency sweeps, say 100Mhz Example: a saw tooth frequency of 100kHz changes the frequency linearly from 2.4GHz to 2.5GHz in 10 microseconds The transmitted signal is sent into the world via the antenna The received signal that bounced back from an object on a distance d from the antenna is received back with a delay of 2d/c seconds (c speed of light 3*10E8m/sec). Example: if d is 3m, the delay is 20 nanoseconds. During this delay the frequency of the transmitter has increased 200kHz versus the received signal. (100MHz*20nsec/10usec) The transmitted and received signal are combined (mixed) and passed through a highly nonlinear element, i.e a diode. The output of this process are waveforms that include the sum and difference of the 2 signals and their harmonics Through proper filtering we can isolate the frequency difference (200kHz), calculate the delay (20 nsec) and the related object distance (3m) Kind regards

[@AndreasSpiess]

Thanks for your explanations. I only doubt if or how all these functions can be done with only one active component. That is the miracle for me... If you look at a newer video we use the principles you mentioned for a bicycle counter. But this device will have much more parts.

[@jonahansen]

Dude - did you copy that out of a textbook? Nice explanation for doppler ranging radar. But that's not what this does. It just detects motion by mixing the transmitted and received signals together and detects a low-frequency beat. No ranging info. No speed info. Just detects motion.

[@researchandbuild1751]

That is not the principle how these work, though. They are simple regen style recievers

[@thomaspatrick4564]

Andreas Spiess, you are putting out very good content. Thank you! You are having an impact on the world.

[@AndreasSpiess]

Nice to read. Thank you!

[@3amali1]

Excellent details. Thank you. It will be great if you can make a video on using those as metal detectors! Like detecting metal hidden underground or maybe behind a large lump of sand. Those treasure hunters will love the video :)

[@AndreasSpiess]

Thanks for the feedback. Maybe I will try it once...

[@immortalsofar5314]

Unless the ground is dry, wouldn't the moisture swamp the return signal?

[@fullsolutionslab]

Nice introduction in Mircorwaves. I like your channel very much.Also becaues you are a swiss guy too :) It's very nice to see, that we have such brillant heads in our small country ;) Since 3 days I played around with the RCWL-0516 and I'm very happy with it. Stay healthy and I hope a lot more videos are coming up :) Next I want to build a LoRa Gateway because in my region no one have it. A liebe Gruess und sunnigs Wätter :)

[@AndreasSpiess]

Wenn es dich interessiert kannst du hier mal reinhören: www.srf.ch/sendungen/digital-plus/ue60-influencer-landet-grosserfolg-mit-elektronik-videos

[@fullsolutionslab]

@@AndreasSpiess Gerne, mache ich gleich mal :) Herzlichen Dank für den Link! Was ich wirklich so toll an deinen Videos finde ist, dass du es auf eine Weise rüber bringst, die selbst ein nicht-Elektroniker daraus schlau wird. Dafür ein herzliches Dankeschön. Behalte dein way-to-do bei, denn dieser ist wirklich genial. Schönes Wochenende und herzliche Grüsse aus Bern

[@AndreasSpiess]

Vielen Dank!

[@kmikeru]

I bought a sensor which is marked "2.7GHz" from Aliexpress and was quite surprised by the spectrum of signal which it emits. It is not a narrow "spike" but rather wide, maybe 1 MHz wide. Is that happening because of poor Q of PCB resonator?

[@AndreasSpiess]

I do not know, because I was not able to see much spectrum below 3 GHz.

[@ABaumstumpf]

1 MHz isn't that bad for these type of devices. with an arduino your frequency can vary as much as 0.5% - at 3 GHz that would be 1.5 MHz just from inaccuracy.

[@aka10gu]

Excellent! Very professional and comprehensive. Saved me tons of work... and money! Thank you, Andreas. I'm looking forward to your next video.

[@AndreasSpiess]

Thank you for your feedback!

[@imemyself2820]

@Andreas, some new LiDAR models entered the market, you could test them maybe?

[@AndreasSpiess]

Any links?

[@imemyself2820]

This one is the original of the cheaper LiDARs on the market but currently sold out: www.3dxr.co.uk/product/benewake-tfmini America: www.seeedstudio.com/Seeedstudio-Grove-TF-Mini-LiDAR-p-2996.html America 2: www.robotshop.com/en/benewake-tfmini-micro-lidar-module-12-m.html This one is a China knockoff but perhaps the same: www.aliexpress.com/item/RCmall-Lidar-Range-Finder-Sensor-Single-Point-Micro-Module-for-Arduino-Pixhawk-Cable-Benewake-TFmini-Drone/32852024277.html High Quality LiDAR for reference (older) : www.robotshop.com/en/lidar-lite-3-laser-rangefinder.html

[@AndreasSpiess]

Thanks for your links. I will look into the matter.

[@adriangarulay5529]

Andreas , Thank you for your articulate understanding of this technology.

[@AndreasSpiess]

You are welcome!

[@paulhendrix8599]

I don't usually like videos on request, but I had to make an exception.

[@AndreasSpiess]

Thanks for liking. I hope, I did not request it. I just know, that many people forget it..

[@MaxintRD]

Good video. I like how you compared these units and gave a clear overview of their main advantages. (Good to see I picked the right one when randomly ordering the cheapest radar-sensor I could find). Thanks!

[@AndreasSpiess]

You are welcome!

[@ulanbat0r]

thank you for your effort. this was interesting AND useful!

[@AndreasSpiess]

Thanks!

[@mrdovie47]

I ordered some of the RCWL-0516 to try at home. If the microwave circuit is a regenerative receiver, it will transmit as well as receive. This was a problem with early regenerative receivers, they interfered with other receivers and could be detected easily. These may be detecting motion by moving objects interfering with the regeneration.

[@AndreasSpiess]

Well possible. BTW I built such a (tube) regen receiver in another video...

[@claudiog.7397]

"of course the technology can also be used against us" LOL

[@AndreasSpiess]

:-)

[@briancrane7634]

Hello, I am a radar systems engineer for 30 years. It looks like the antenna is a double-dipole and is intended to mount in a simple tube-like cylinder. In this mode it would be a simple motion detector which is what you said correctly at the beginning of the video. However the price is amazing and I will get some of these for proximity sensors around my home as the basis for a new security system. I am also subscribing to your channel. Thank you very much for this video!

[@AndreasSpiess]

Great to have such subscribers! Is this simple design with only one transistor something you know? Because so far, nobody was able to explain us how it works and which principle it uses. For example, I was able to prove, that the modules work ok even if other modules are in close proximity. But as soon as I switch one module off or on, the others trigger. Another question is, if it senses speed and in which direction (from-to or also across). I did not do any proper tests about that.

[@briancrane7634]

Yes, with a common ground signals can go in both direction on a wire in TEM mode, so TX mode signals to from the XO to the TX transistor, received signals go the other direction, through a circulator and into the RX front-end, in this simple setup harmonics and distortion are ignored since this is a simple switch motion/no motion based on Doppler signal which is what you said. These modules seem to be in the 5GHz band that is internationally not regulated it is the "other" ISM band that very few can use because of lack of range. In this case that is positive attribute since range-to-target is so close. For several units close together yes there is interference but since the unit only detects Doppler. It is like saying one unit can use another unit's TX signal as long as there is no motion. The other units trigger when a unit is switched off because they detect a change in this signal when a unit goes down the XO does not stop abruptly but changes frequency as power is removed and voltage from the power supply capacitor sags. That is what the other units are detecting.

[@AndreasSpiess]

Thanks for your explanations!

[@gandsnut]

With outstanding content like this, it's really a crime that AS doesn't have 200,000 subs. Soon, I trust!

[@AndreasSpiess]

Thanks for the nice words!

[@billybbob18]

Are Jayem He's speaking to a specialized group with this subject matter. He is very good at what he does, but there are not many who have an interest in sensors.

[@gandsnut]

Besides the particular topic (sensors) - which is gaining traction with many makers and electronics diy hobbyists - I find a good number of our host's presentations balanced, informative and accessible, and creatively interesting. By doing this, what would be specialized subject is delivered for a wider audience to ponder and spark ideas.

[@billybbob18]

Are Jayem I definitely agree with you.

[@hbirtt]

Thanks for taking the time to run through these. Wish I had found this video before I bought 5 of each of the RCWL and HFS boards. I need 3 working units (always buy extra from China). Looks like the cheaper boards will be the best fit. NBD. At the prices these things are going for these days I can throw the others in a drawer to use for something else some day. The HFS boards will be better if I need something to be directional.

[@AndreasSpiess]

I hope they will work for you. Keep the power lines very clean (there are a few discussions about that)

[@RoterFruchtZwerg]

Are you sure the RCWL-0516 does not work on 3.3V? I really cannot see a reason why it shouldn't work if you power it with 3.3V on the 3.3V pin. Usually a voltage regulator doesn't care much if you power its output with the right voltage and no input connected... Even if the voltage regulator is integrated within the IC. And I don't think the unregulated input voltage is used anywhere else except on the voltage regulator input. You should try it.

[@AndreasSpiess]

You are right. I tried it again now and it works. I do not know what I did last time... BTW: I did not see a voltage regulator chip on board.

[@alevi7856]

@Roter . If I understand you well, the 3.3V pin can also be used as an INPUT (on +3.3V) as long as the Vin pin is not used ... am I right ?

[@AndreasSpiess]

Yes

[@alevi7856]

Thanks, then I'll try to power the radar sensor from the 3.3V output of my ESP8266 board.

[@robbateman9836]

Yann M I'd like to know how you get on.

[@techydiy]

Thanks Andreas, I always enjoy your videos.

[@AndreasSpiess]

You are welcome!

[@peternierop3241]

Cool stuff. I might buy a few to play with

[@AndreasSpiess]

:-)

[@szulewsk]

Thank you for your thorough analysis of the devices. A fine video presentation of your results.

[@AndreasSpiess]

You are welcome!

[@lostrafos]

Hello Andreas, Before I begin, I like your videos a lot. In your video at 15:04 min. you explain that the RCWL-0516 cannot work in a 3.3 volt environment, I make a mistake and put 3.3 volt as input voltage. So 3.3 volt on the 3.3 pin and GND on the GND pin then a diode connected on the Out pin and GND, and wonder the RCWL-0516 works also, it detects movements like before. I think that you can use the module from 3.3 volts and if you have 4 volts till 28 volts you must connect the input voltage on the VIN pin. www.elecrow.com/rcwl-0516-microwave-radar-sensor-switch-module-body-induction-module-4-28v-100ma.html Greetings from Holland, Jan-Henk van Kesteren

[@AndreasSpiess]

Thanks for your link. Maybe there are different versions of the same modules around, as in many other cases. Or I did something wrong, which also happens from time to time.

[@ignacios3992]

Genial! Justo acabo de comprar el RCWL-0516 para detectar la presencia de intrusos, una muy buen explicación amigo! Gracias por compartirlo con nosotros

[@AndreasSpiess]

You are welcome!

[@AdeDerby]

The 1.8 GHz could be a DECT phone

[@AndreasSpiess]

Thanks for the hint. This is well possible because one was close by.

[@PatrizioBekerle]

Thank you for the video, Andreas! I love your channel! I want to report that the RCWL-0516 works great with the Sonoff Basic switch with the OUT pin on the Sonoff's GPIO14 pin and the 3.3V pin connected to the 3.3V of the Sonoff. I use it to report movement via MQTT.

[@AndreasSpiess]

Thank you for your feedback. I am sure it will help other viewers!

[@Mobeone]

Great video Andreas! I found this GitHub repo that has a schematic of the RCWL-0516 : github.com/jdesbonnet/RCWL-0516/blob/master/README.md that you may find useful. Thank you for the great videos!

[@AndreasSpiess]

Thanks for your link!

[@bjl1000]

I thought youtube didn't allow links in the comments?

[@bramhartgers3437]

Great video!! I bought the HFS-DC06H sensor after seeing your video. Problem is it no voltage on the output with my multimeter. Also the on board led is not blinking ad all. do you think it is broke? Or do you measure otherwise?

[@AndreasSpiess]

Unfortunately I cannot do remote debugging. You should see a voltage at the output.

[@bblancka]

Great hands-on test ! Thanks ! More info here: github.com/jdesbonnet/RCWL-0516

[@AndreasSpiess]

Thanks for the link.

[@venkateshe7506]

Thank you very much. Appreciated.

[@lammingmik]

Top notch video. Practical, succinct, objective. A benchmark for review vids.

[@AndreasSpiess]

Thanks! :-)

[@RafaelSisto]

Hi, great video! Did you make any experiemnts blocking or directing these signals? I've made tests with grounded aluminium foil blocking a RCWL0516 with no success.

[@AndreasSpiess]

One sensor has a metal case on the back for directionality and it seems to work.

[@klassichd10]

Thanks for this comprehensive and systematic comparision. It comes very handy to me because I also received a sensor similar to XYC-WB-D1 for playing around and looking for a helpful application. Unfortunately (?) most helpful application are already covered in my environment. It is really an excellent work to do all that with just one (1) transistor and some passives. Chapeau!

[@AndreasSpiess]

That is what I think, too...

[@flightmaster999]

I just found your channel, great video! I like how precise and concise your comments are. Brief, clear and to the point. You have a new subscriber! And you made me laugh so much at the end when you said "If true then like". 🤣

[@AndreasSpiess]

Welcome aboard the channel!

[@ajoytamhane6297]

Hi Andrea thank you for the efforts in reviewing the sensors. For the proper working of the sensors perhaps you can cross check the hypothesis put by sirus o your spectrum analyser. The signal should be visible in the UHF band, based on the geometry of the antenna on the PCBA.

[@AndreasSpiess]

Their frequency is above the limits of my SA :-(

[@MrNagylzs]

Movement is almost never detected by the red shift (frequency change) of the reflected radio wave. Speed is measured in a totally different way, with a so-called doppler radar. Doppler radar measures the distance of an object by measuring the time elapsed between sending out and receiving the same signal. It sends out two singals, and measure the change of distance between those two signals.

[@andrewainger]

I think there is a misunderstanding here? The RADAR I was working on cost just under £2,000,000 and use multiple pings etc. However, I understand these very low-cost units operate exactly as described in the video. I purchased mine for

[@peterjones7703]

Is it possible to remove the chip on the PCB (but keep everything else as is) and replace it with a STM32 MCU to measure distance & speed?

[@AndreasSpiess]

No. They only can measure presence

[@cooper6717]

Awesome! I have been waiting for this video since you mentioned it in one of your mail bags, thanks for coming through with the usual great content.

[@AndreasSpiess]

Thanks!

[@pagutierrezn]

You continue to read my mind and post the videos just when I need them. Thanks

[@AndreasSpiess]

:-)

[@francoisguyot9770]

Thorough review that answered all my questions.

[@AndreasSpiess]

Thank you!

[@basilkatakuzinos659]

Hello Mr Spiess, that noise at 1800Mhz that you labeled is a GSM band used by the telecommunications industry, it’s known as DCS-1800 or B3 LTE

[@AndreasSpiess]

Thank you!

[@dmitchler]

Great video! Did try the glass test with the glass just in front of the sensor? I am thinking of a motion sensor for the front porch with the unit mounted on the inside of the glass window above the door.

[@AndreasSpiess]

Standard glas in front of the sensor should be ok.

[@RelentlessHomesteading]

Very nicely done - appreciate your thoroughness on the testing; gave me some background on what they might do.

[@AndreasSpiess]

Thank you!

[@ivanarakistain3885]

Hi Andreas, I would like to use HFS-DC06 behind a mirror in order to detect movement. As you know, mirror is plated, so my doubt is weather it will work or not and if I can decrease sensitivity for a range of 1-2 meters. Thanks

[@AndreasSpiess]

You have to try. I do not know.

[@JHawkin8tor]

Great video. FWIW, I'm using 3.3v input via Arduino on the RCWL-0516 with no problems, so it is definitely the sensor of choice for me.

[@AndreasSpiess]

Thanks for the feedback.

[@igotes]

Just found your channel.. Great work! I appreciate the comprehensive analysis of these cheap sensors, as the ebay listings tend to give little information.

[@AndreasSpiess]

Thank you!

[@mgbetta6300]

I very like your videos and how you do explain the comparison. You're now my favorite youtuber.

[@AndreasSpiess]

Thank you and welcome to the channel!

[@ferencszabo3504]

I wanted to combine the RCWL-0516 with some cheap 433 sender with a fixed codes but the problem with that setup is that the 433 sender is producing the signal when I manually or by the RCWL cut off the power, right in that moment which is weird. It probably stores some power in its coils or caps...

[@AndreasSpiess]

Strange.... I hope you will find the error.

[@CrazeUK]

Great video. Never new these existed. Would be interesting to see a video demonstrating when to use either radar, ir or microwave sensors. Also, would be great to see what can be achieved with them, like can the device give a different reading dependent on proximity

[@AndreasSpiess]

You can do your tests. these devices are not expensive ;-) I recently did a video about the new 24GHz sensors, BTW

[@ianpaul6369]

I was looking for one of these devices to use in the UK for remote security applications. After looking around there was one company who could supply a module which could detect at 75m, (people/vehicles) with current draw down to 1mA. Not really cheap but top quality. You can also purchase ready to go radar speed camera, with a warning sign: slow down, over 20mph, etc. I never knew these devices were available to the general public but they are.

[@webstermedical5737]

There is one of those speed signs at the local retirement village, indicates your speed either in flashing red or green. What is *really* cute, is that it detects *direction*, indicating only traffic approaching, not departing. That requires somewhat more sophistication.

[@AndreasSpiess]

I think, these devices work with a different principle, because they can also measure speed.

[@kboo918077]

Very good video, just a question: did you try to make an antenna to have a thinner angle? It should work isn’t it?

[@AndreasSpiess]

No, and this is not easy as it is on microwaves

[@dastiieto7651]

Hi Andreas... Nice Video.. it helps me to choose the right Sensor for my Project... I still have a question... I choose the RCWL-0516 one.. If i want to reduce the detection Angle, i just need to add a piece of Glass in the right Position... right? Do i need normal Glass? Or do Plexiglas the same work? How thick the glass have to be? Kind regards..

[@AndreasSpiess]

I would use metal, not glass for that purpose. Normal glas or plexiglas will not work

[@dastiieto7651]

@@AndreasSpiess yes, but in your Video, you cant detect your friend behind a glasdoor.. and i saw a Video, a guy use the same Sensor, put a empty can above it and it still detect everything.... I try to find it and give you the link...

[@mauromorandi6794]

Great video!....With this rcwl0156 module, will it be possible to measure the distance to an object, using Doppler, changing the antenna and making it directional?

[@AndreasSpiess]

No. These modules only detect presence.

[@AnshiAtUtube]

Awesome video Andreas! Do you know if any of these mmWave radar modules can output the distance/angle between object and sensor? All of these seem to only output HIGH/LOW values.

[@AndreasSpiess]

You can get other radar modules. But they are very expensive compared with these small boards. They can measure distance and speed. I am not aware of angle.

[@AnshiAtUtube]

@@AndreasSpiess Have you tried any of these more expensive ones, which you could recommend to me?

[@AndreasSpiess]

No, I did not test them.

[@jacquesvermaak373]

Hi Andreas, I only comment now (quite a while after watching this for the first time). I got myself 10 RCWL-0516 sensors and I just LOVE them. I automated my lights in both my house and workshop. I even made an alarm sensor unit to monitor movement at my main gate. Thanks to this unit I was able to catch two thieves in the act of trying to break in (South Africa has very high crime rate, so you need to do anything possible to give you an early warning) I did however found that if you are running the RCWL-0516 over a long distance you need to add a PI filter. Two big sized capacitors (100-470uF) with a 10ohm resistor in series (two caps ground tied to ground, one cap receives the supply power, resistor in series to the next cap positive and that goes to VIn of the RCWL. That completely eliminated any false alarms. The unit is very sensitive.It picks up small animals such as pigeons and cats. Oh, and watch out for FOG. Moving moisture seriously affects the unit. That was the only time it failed (false alarms). So for people living in high fog areas, sorry, this will not work. Thanks for a great channel. Love your work. Keep it up.

[@AndreasSpiess]

Thanks for sharing your experience. I did not know about the fog. And maybe it would help to have two sensors in the same area to distinguish between small and bigger "animals". Only if both see something it is big enough.

[@jacquesvermaak373]

Hello again, I found that these units are quite sensitive. I do have two units spaced about 6 meters apart (my original idea was to detect direction of movement). That works but it senses both human and small animals (i.e. the neighbors cat) with the same accuracy. I programmed my Arduino Nano to now count the number of triggers or monitor the duration of how long the unit is triggered before creating an alarm. This did eliminate many false animal triggers, but if the little critter decided to hang around the sensor, unfortunately then the alarm goes off. My HD Closed circuit camera system is then used to confirm friend (small animal) or foe (real criminal)

[@jensoolichaengvminkooknamj3160]

Yes, it worked for me in the hall all right but not in the bathroom, when I kept the unit on a plastic drum full of water. Somehow the effect was dampened and worked only within a few cm as opposed to 3-4 m in a open dry hall.

[@gurudathsv3924]

Hello, thanks for the great explanation. Am facing sensitivity issue on RCWL-0516. On the fist day sensitivity of the motion was very good even at the distance of 5meter. After a day suddenly the sensitivity drops to less than 0.5m . Is this behaviour see with any one ? If you have any suggestions/solutions please suggest.

[@AndreasSpiess]

No, I did not see a degradation over time.

[@paulstross4476]

My project with these OWL sensors as a movement sensor, with an ESP8266 to send data, was frustrating with false signals and unreliability until I ensured the WiFi was OFF for most of the sensing time loop while movement pulses were counted and only turned on briefly to transmit the counts! Results:= lower current draw and great reliability. Not surprising but it look time for me to figure that out. Thanks for your inspiration.

[@AndreasSpiess]

Thank you for sharing your experience. Looking at the Spectrum analyzer in my newest video you saw that they work around 3 GHz. Which is very close to 2.4GHz Wi-Fi. So it is no wonder that you get cross-talk.

[@vivek77]

Hello Andreas, I just love your videos ...Do you know if I can use it to measure the speed of the ball ?

[@AndreasSpiess]

No, they doe not measure speed.

[@SidharthMakhija]

Hey Andreas, great video. Where did you get the third hand shown at 13:48 in the video? I've been looking for something like that for a while now with no luck! :D

[@AndreasSpiess]

Here I built it: kzbin.info/www/bejne/bpKTf5uGlsmDb9U

[@SidharthMakhija]

Thanks Andreas, I'll check it out!!

[@MuhammadArshad-hl9hh]

Very useful comparison video . Great effort is done .

[@AndreasSpiess]

Thank you!

[@coastwiseable]

Hello Andreas, Could one restrict(reduce) the field of view of any of these radar detection modules using a parabolic dish or some other type of directional antenna (yagi?) in order to get some sort of bearing of a detected object?

[@AndreasSpiess]

One of teh sensors has a restricted field. So it is possible, but not easy because of the high and unknown frequencies.

[@ishtzavah]

Thank you Andreas. If you place one of those inside a can, will it make it more directional and increase the effective detection range?

[@AndreasSpiess]

Maybe. It depends on the dimensions of the can. But experimenting is for sure fun!

[@georgewashington421]

Great video. Appreciate the effort to examine and compare the most important characteristics of each unit with a scientific approach. I agree with you, even if the units are simply measuring the variance in transmitter output to determine motion, some sort of return circuit is required. Thanks again.

[@AndreasSpiess]

You are welcome!

[@diydsolar]

Great video Andreas. Do you think that OUT pin can be used to trigger a transistor which trigger a relay ? how much current could you take from OUT pin ? Regards,

[@AndreasSpiess]

You can use it to switch a transistor. I assume, you can get a few mA. But I did not measure.

[@savvayiannos]

For RCWL-0516 how can i change the delay time to about 1 sec? Thanks

[@AndreasSpiess]

I do not know. I always used this module with a microcontroller and did all the timing there.

[@anthonyrigden1859]

Can I use the RCWL-0516 as a counter. For example, to count the times a bird visits a nesting box. It would need to detect movement down to a few inches. Many thanks for a great review.

[@AndreasSpiess]

This sensor just gives you a signal if it detects something. So, you have to solve two problems: 1. Try out if your birds are able to trigger a signal and where you have to place the sensor (I think, it should be possible on a short distance, but I am not sure, because birds are very light and do not contain lots of water) 2. build a microcontroller to count the events

[@TerryE-UK]

Very good, thanks. Have you thought about using aluminium foil, say placing your module in a project box lined with foil on the sides but with "clear" lid? This should give a crude ~120° cone sensitivity.

[@AndreasSpiess]

If you look at other comments: This should work. Of course, it depends on the application.

[@XIIIStefanC]

Video was very interesting to watch and the comments contained more interesting information, subscribed.

[@AndreasSpiess]

Welcome to the channel!

[@abualis1178]

Great informative session, I am a newbie to this however I have a question if this sensors at most they detect an object at 8 m surely they are not the same used in the aviation radars and fields, ignore my lack of knowledge I could't make the link.

[@AndreasSpiess]

They use completely different devices and also different technology in aviation and police.

[@abualis1178]

@@AndreasSpiess I thought so, are there any civil sensors that can be used to detect "unfriendly " animals, foxes, hyena, or even thieves at a larger range ie:500 meters and above, it's mainly to protect a remote farm and compatible with an Arduino board. Thanks you

[@Astronomer6573]

Have you tried adding aluminum foil at the back of the sensors(without shorting them), and at an angle in front of the sensor to produce some sort of directivity?

[@AndreasSpiess]

No, I did not try it.

[@felixh.7501]

I made a small project with the RCWL-0516 and all worked fine...until I put it in a plastic box along with a Rpi Zero W. The Pi reads the data from the radar on GPIO 17. I dont understand why the plastic box is blocking the radar, any idea? Did you try enclosing the RCWL--516 in a box for your test? Many thanks in advance for your tips.

[@AndreasSpiess]

Are you sure the effect comes from the plastic and not from the RPI?

[@felixh.7501]

Hi Andreas, thank you for your response! Your question made me redo some tests. I isolated the radar in a similar box, and not with the Raspberry. The effect is that the radar detects much better already, it gives a signal on any move. I also found a soldering problem that was adding to the issue when I was forcing the radar in the same box as the Pi, and that was the main issue. All in all, the plastic box doesnt stop the radar to work, but it seems - it is an impression based on several tests - that the radar should be at least 5-10 cms from the Pi to be optimally working.

[@Emtron_Technologies]

Excellent comparison Andreas. I will be using in my future projects.

[@AndreasSpiess]

Thanks!

[@SimonFiliatrault]

nice! so those modules have on/off output for detection. would it be possible to get an analog output to detect for example plant growth, or how much of the signal is reflected or something similar.

[@AndreasSpiess]

+Simon Filiatrault I am really not sure, but they should detect speed of change more than presence.

[@SimonFiliatrault]

You're right! Not sure what I can use to detect plant growth! Maybe levels of specific light frequency reflected back from leaves? Thanks for the hard work you are putting in all this! Amazing!

[@FritsvanDoorn]

Hello Andreas. Interesting video. I was thinking, if you cover one side of the sensors with some metal plate, will it become direction sensitive? Maybe the plate must be connected to Ground? I am looking forward for the results.

[@AndreasSpiess]

I had one sensor with a metal shield and it worked. So, it should be possible. I would connect it to ground. At least to begin with.

[@compubyte2010]

I know this is old. But. I have a question. you didn't cover the one thing I was interested in knowing? the Voltage range. U tested at the lowest? out of curiosity, if it was increased to max ( on like the HFS-DC06) would that increase the range / distance via increasing the voltage? and if so. how far would it reach on max voltage?

[@AndreasSpiess]

No, I did not try to increase or decrease the voltage.

[@compubyte2010]

@@AndreasSpiess Well, do you suspect increasing the voltage might increase the range of the device? ( theoretically )? i've ordered a few different ones. they are on the way.

[@billw2976]

Just watched your video, good job. I would like to know if any of these operate in the Ku band and could have a transmitter range of over 1/4 mile around 5/8 kilometers. These would be great fun to mount on your front bumper and drive down the highway setting off radar detectors.

[@paolofiorini3259]

similar interest for another application. any solution in the meanwhile? thanks!

[@dontjump-r2d2]

Nice work. It was pleasure to watch. Many thanks.

[@AndreasSpiess]

Glad you enjoyed it

[@frankl1955]

Great video, thanks. I noticed a video of the HFS-DC06 that had a ¼ wave antenna sticking out the small hole on top, is that needed ?

[@AndreasSpiess]

You have to ask the guy which did this video, I think.

[@prlombaard]

I have only recently discovered this video after a colleague of mine mentioned these radar sensors. Very good video as it contains all the questions I would’ve asked but do not have the time nor the Morne to perform this research thankyou. All you tests were performed indoor. Are these sensors mainly used indoors or can it be used outdoors? Also do other moving objects like pets trigger these sensors? Or moving trees when sensor close proximity ?

[@AndreasSpiess]

There are a few comments about outdoor usage. Wildlife seems to be a major source for false alarms.

[@prlombaard]

Andreas Spiess I have purchased a RCWL-0516 microwave radar PCB and will be testing it outdoors. Once again thankyou for your videos.

[@NicolasVietnam]

Thank you very much, a great video that will save me some unuseful orders from AliExpress, and a lot of time testing ! I have a few RCWL0516 and I will order HFS-DC06 for when I need a better range. Do you know if you have any built in UV/... filters in your window glass ? It could contain some metal and block the radio waves ?

[@AndreasSpiess]

My house has just ordinary glas without any metal film

[@Quivive2001]

Dear Andreas, I had a lot of troubles with the RCWL-0516 Microwave Radar Sensor!!! After some Time the sensor started to trigger without any purpose? In the Internet I found many people with the same issue. Do you have an idea what went wrong? Thank you for your efforts and Greetings from Frank

[@AndreasSpiess]

There were some discussions on how to improve its design. But I do no more remember. Google should know.

[@Quivive2001]

@@AndreasSpiess Thats why I ask!!! I read most of them! In the end the vast majority came out with growing solutions with remaining problems! The conclusion seems not to use it!!!

[@pedro.federici]

Very nice comparison, Andreas!

[@AndreasSpiess]

Thanks!

[@andrew2004sydney]

Are there health aspects to consider? Say you have a 24GHz radar pointing at your office chair or bed to turn the lights on for many hours per day. Would there be any problems from sitting in the path of a radio transmitter for a long time?

[@AndreasSpiess]

The current used by this devices is very small and is not only used to produce radio waves. So the overall "smog" added by such a device is probably much lower than your Wi-Fi or LTE Smartphone. Also, keep in mind that signal strength is reduced by the distance*distance to the sender. So, you easily can reduce smog by placing all your devices a little further from you (not in the pockets of your pants)

[@rcrack2k]

Hi, i need a sensor to detect cars when waking up from deep-sleep. What sensor do you prefer? Doppler-Radar must be as fine but only rely on movements is not an option. I do not need distance massuremenets, but i need a obstacle detection of metal.

[@AndreasSpiess]

I do not know how to solve your problem. There are many options, all with advantages and disadvantages.

[@venkateshe7506]

Thanks. I use these extensively as for detecting motion outside of my home, but these has some issues. It will triggered motion when there is rain. It even can trigger if there is small movement like a plastic cover rolling on floor.

[@venkateshe7506]

One more thing I have enclosed these modules in a metal casing to stop it from false triggering as it is used detect motion in all directions, except for one direction.

[@venkateshe7506]

This is the one I use www.aliexpress.com/item/DC-SSR-DC-Microwave-Sensor-Switch-Radar-Switch-Module-Human-Body-Induction/32715462134.html

[@AndreasSpiess]

Thanks for the feedback concerning rain. Another viewers asked about that. And of course, it is like with everything: You have to find a compromise between sensitivity and false alarms... Concerning Metal housing: I think, this is a good idea if you want to restrict direktions

[@venkateshe7506]

Thanks. Yeah for now I am turning motion sensor whenever there is a presence of rain (not a good idea).

[@soportedec]

Congratulations for your work. This type of videos are very useful when making a purchase decision.

[@AndreasSpiess]

Thank you!