Your channel has one of the best audiences I have ever seen. So many comments are helpful and give new insights. Also, taking your time to reply to almost every comment is just wonderful. I am not even working with electronic, but I can feel this is a magical place.

Video link for those interested - ukposts.info/have/v-deo/nHGrfI6nh2l3xH0.html

Thank you, Peter!

The LD2410 is also supported in ESPHome that exposes it's sensing data to Home Assistant.

@@ethzero is that the Bluetooth version or via serial? I have without Bluetooth, and used serial to configure. In use with only the high/low signal for detected or not. But can be used in so many ways :-)

I think LD2410 needs 5V

@@saninnsalas it uses 5V Power Supply, but have 3.3V logic. I think it has its own 3.3V reg onboard for stability.

You are right. I covered the LD2410 in a later video.

:D Spiders are the best!

I understand your frustration when troubleshooting this issue. Faulty Dupont wires and cheap breadboards have almost made me crazy when building and testing new projects. Based on your experience can you recommend a good radar sensor? I need a couple of them to detect birds and trigger an ESP32-Cam module.

@@oladunk9986 The versions I was using were pretty cheap and I believe the same as the XYC-WB-G1 as the switching time was the same, although you probably want a five second or less on time if you just want triggering, it will give you more captures per minute. In that case the RCWL-0516 or HW-MS03 would be good candidates, although the more expensive HFS-DC06 is likely to be more stable with less false triggers. The best part in detection with these is the daytime performance matches night, unlike PIR, and the sensor can be sealed from the elements. The downside is they can be triggered by wet foliage in the wind, insects and sometimes just nothing (may actually be flying insects...), but they are cheap. Good luck.

Wonderful story; and although spiders are not classified as bugs, this is definitely....real debugging.

Awesome engineering have done. Simply wow!

You are right. As said, this is an old video and in the meantime, a few viewers suggested this. It is good because if it is a receiver, it is prolly more legal ;-) BTW: I once made a video about a tube Regen receiver…

Thank you for your kind words!

I do not know, but our home is quite old and in Switzerland, they only recently started with this metallized glass.

@jacquesmertens3369 Switzerland is very versatile: Some Swiss chocolates or candies might be even cheaper 🙂

Indeed, Switzerland is expensive. But I experienced that other "holiday" countries in Europe catch up quickly :-(

Indeed, for me, it is still unbelievable how sensitive they are!

I will try ;-)

Thank you!

These devices are not real radars, they are regenerative receivers (mentioned in other comments). Do there is no worry about interferences.

I don't anything this size will emit anything near the power required to drown out such a high powered radar.

Rain radars (actually called weather radars) operate in the 5GHz wifi band. Wifi routers that operate in the range 5250-5350 and 5470-5725 MHz must use a mechanism called DFS or dynamic frequency selection to change channel if they detect a weather radar. DFS is not required in the 5150-5250 MHz band and in the 5725-5875 MHz band. Some manufacturers allows the user to disable DFS, which is is illegal and causes weather radar interference. Problems usually occur with WIFI access points installed outside, on top of a hill, or in a tall buildings.

@@atmel9077 The frequency of the rain radars depends on the intended range, not all operate around 5 GHz. Higher frequencies have a shorter range, but better sensitivity to smaller droplets. For vertical profiling, around 90-100 GHz is used, short range, but much better sensitivity for smaller droplets. But indeed, there are several (proposed) license-free channels that are of concern for observations used for weather, including passive microwave for water vapour measurements. Those can't be put on a different frequency to avoid interference.

​@@MrGeekGamer The transmitter of the rain radar is not the issue. The reflected signal from a collection of raindrops is small, and drops off quickly with distance. (1/r² for the transmitted beam, another 1/r² for the reflected signal, with a strong dependence of the reflected signal on the droplet size). Even low power transmitters can easily overwhelm the reflected signal, especially for small droplets.

These sensors work very different to the „real“ radars you describe. These sensors only have one transistor which has to do all functions…

Maybe you have also a look at the LD2410 (I also made a video about them)

I will! Thank you.

I will. Thanks!

Thank you!

You are right, they are regenerative receivers!

The solar videos were not too successful. So I was not sure if I wanted to du an update. But maybe I will do it now…

They should be widely available.

Thank you for sharing your experience!

Thank you!

I agree.

Thanks for sharing your experience!

Thank you!

Thank you! Was my pleasure, too.

Maybe you now find a project for them ;-)

Thanks, you too!

@@AndreasSpiess Thanks!

I agree that these sensors are. Good choice. I already made a video about them…

Thank you for sharing your experience!

Another video on radars is planned. But I still did not find a cheap radar capable of detecting on a long-range :-(

Thank you for sharing your experience. This sensor seems to be very good. However, it is a bit pricey if you do not need its particular features...

I once made a video on how to hack IR devices. But it was not as easy as you describe ;-)

Gracias!

Thank you for sharing this enhancement!

I will. Thank you!

Thank you!

Cool. Thank you for sharing your trick!

I do Not plan intros for the remaining videos, but maybe add the original number in the description.

Just saw your pinned post on regenerative receivers.

Indeed, when I made the video, it was not clear. Only after reading some comments, it became clear that these are "only" receivers...

As many others stated, they are not real radars. I had real radars ( they are more complex) on the channel. But their range is not much longer.

Thanks for sharing! So the HFS-DC06 and the SK-600 are in the 5GHz Wi-Fi band!

:-)

Thank you for sharing your learnings. Interesting!

@@AndreasSpiess the module I used appeared to have a earth plane, but was still sensitive in the reverse direction. If the frequency used is 24GHz, then one might expect an effective stand off distance from the carrier board earth plane to be 1/4 of a wavelength, approximately 0.3115 cm, as this would produce a voltage node at the surface of the earth plane. The next standing wave would be at 3/4 of a wavelength. This is the standoff distance that can be achieved using the roll pin plug and socket as the interface. In practice, I doubt if the frequency is that well controlled, and the precision of the standoff distance is not that accurate. My test equipment does not reach 24GHz,, I resorted to looking for changes in the supply current, reasoning that this might show loading of the Tx. There were small changes, but nothing conclusive. The range did not appear to be adversely affected by the earth plane of the carrier board, but it did greatly increase the directionality of the beam.

Thank you! You too!

I am also puzzled by how sensitive these cheap devices are!

Thank you for the info!

I will! Thank you.

I agree. But these sensors are not made for that.

And we have 36 degrees outside ;-)

@@AndreasSpiess Stop bragging 😒, Andreas. 36 is cold for our summers.

Thank you! 😃

:-) 73 de HB9BLA

I do not know the laws around this topic :-(

Thank you! You to.

Mach ich ;-)

You are welcome!

@@AndreasSpiess curious what happens when i mount one sensor on each table of ma office to measure how many seats are available. At the 5-7m range and 4x 160cm tables next to next do they disturb each other? Or can i focus the beam by using a bowl lined with Aluminium foil ?

@@olafschermann1592I do not know, you have to try.

Indeed, these devices are regenerative receivers, not radars.

You are right!

Vielen Dank! Der Urlaub wird hauptsächlich „ums Haus“ stattfinden…

I made a video about the ld2410

I agree

I do not know if they have such a feature in their plans...

Thanks for the info!

I pinned a comment on how they work. They are simple receivers like back in the old days...

The ones shown here vary a lot in frequency. They can be classified as receivers an so are legal even if they transmit a bit.

@@AndreasSpiess Okay, understand. So the principle is at bit different than with dopper radar sensors like RSM-1650 for example..

@@EinzigfreierName It is completely different. They even cannot be named "radars". But I did not know that when I made the video...

Please do! They seem to work on different frequencies.

Back in the day, most electronic devices were quite simple designs, I think. They just did not have the capabilities for better equipment. However, they worked!

???

I share the ESP32 internet using the Wi-Fi hotspot functionality of the smartphone. I do not think that doing it via Bluetooth is a good idea...

@@AndreasSpiess I do already have wifi working but for my application a bluetooth internet connection would be so much better for battery life and end user experience. thank you anyway

@guatagel2454 My experience with these cheap radar sensors: They work best with an own power supply using a linear voltage regulator + caps. Connecting to the supply of a Wemos did not work for me.

I also had false positives. I found adding a capacitor to the power rails and a resistor on the Vcc line to create a simple rc filter fixed it

@@fluteplayerify congrats! I my specific case RC did not help, But in both cases an improvement of the supply path was the key.

There are some posts on the internet about this issue and some suggestions to resolve it. Another possibility could be to use a more modern LD2410 sensor (video #439)

I will! Thanks.

Reinforced most probably will not work because of the metal.

The IC is well known it contains nothing special (no RF function)

@@AndreasSpiess Perhaps one of the inputs will allow conclusions to be drawn about how it works. For sure PCB does not look like 24GHz 🙂It even does not look like 5.8GHz but I will check this using my SDR but that antenna length also indicates lower frequencies. Maybe a super fast transistor is able to generate harmonics. My guess is, this is just called "radar" but principle is something completely different. The human body has impact on resonance or may be even SWR.

@@greekstraycats You will see a signal in the GHz range in the air. As many comments suggest, these devices are regenerative receivers, and they emit a small signal via the antenna.

Agree, or at least look at the demodulated IF on an Oscilloscope. Do you know some good and easy to use software to analyze signals ?

Getting speed information is trivial, just do an FFT to extract the beat frequency. Things like distance measurement is a different story and it's better to use radar sensors dedicated to that.

There is no IF. These seem to be „regenerative“ receivers where the only transistor acts as a transmitter, too.

Keep in mind: They only have one transistor. So such functions are not possible.

No. Maybe you have a look at the video about the LD2410?

No. Cars have different sensors (more sophisicated)

I do not see why I should connect anything to the input if I connect power to the output. As you say, there should be a difference between the two pins. So the input will be cut off by the LDO.

Read the comment about the spider ;-)

Danke!

These devices have no mixer, etc. because they only have one transistor. They are regenerative receivers. The IC have no receiving function, just threshold and timing.

@@AndreasSpiess Yeah, I understood it while watching other videos from you - this is a creative way to measure distances.

@@hankhulator5007 Actually, they cannot measure distance because their "sensitivity" heavily depends on the size of the detected object. They are only suitable for presence detection.

@@AndreasSpiess That's good enough, my project being to couple one of these with a PIR to ensure no false positive. I also have to investigate about such a device that uses one of the more expensive RADAR you presented, the one with 6 little squares - a guy (you ?) has made a device combining an ESP32, a RADAR and a PIR which distance of detection can be set remotely ( ahhh, I found my bookmark about this one back : ukposts.info/have/v-deo/ooabpp2Iio2drX0.html )

From my understanding here is how it works: it's basically an oscillator which is an amplifier with its output going back at its input through a filter. If it is an inverting amplifier the filter gives a phase shift of 180° at the resonant frequency. The amplifier is saturated and operating in a non linear region (fully on or fully off). The reflected signal will self-mix with the oscillator and create a DC offset. If there is motion the phase of the reflected signal changes so the DC offset oscillates at a low frequency. The DC offset is amplified and bandpass filtered (say 1 to 10 Hz) and goes to a comparator which triggers the sensor. More in-depth explanation : because the amplifier is saturated, the collector is periodically shorted to the emitter, when there is a base current. The transmit/receive antenna is connected to the collector. When the peak of the reflected signal is in phase with the collector not being shorted, it will give a residual DC voltage, higher than when the peak of the reflected signal is in phase with the collector being shorted. The slowly varying DC voltage is processed by the IC chip, often a BISS0001 designed for passive IR sensors, as those output a similar low frequency signal.

Vielen Dank. Heute war es auch 36 Grad hier…

Where I live, this is available. "xcluma 5V-30V Delay Relay Timer Module Trigger Delay Switch Micro USB Power Adjustable Relay Module"

Generally, you need a microcontroller to get the behavior you want. Only if the sensor does exactly what you need, you can do without it.

@@AndreasSpiess I'm on solar 12v input. Can usb to 5v. This device puts out 3v so that's my issue. In not electronics educated, I generally watch utube and do understand. But I'm a novice. So some doorbells run of 3v. But probably more amps again. So all I'm trying to do is step up v and a. The 5seconds is ok, for an alarm. It's some 100m away from me, the setup. So audio alarm is good. And if there's continuous movement it will trigger repeatedly. So that's ok too. But ideally I want to trigger a 12v output. So I've seen there are 5v relay boards out there. Just wondered if you have the patience to demonstrate something along those lines. Many thanks.

@@earthlingthings Your questions are far too big for a UKposts comment. Maybe you search for a device that runs on 10 volts and is capable of switching at least 12-volt loads. Or you start with simple things like a voltage regulator to convert 12V to 3.3V and so on and learn all the stuff needed to build such a device.

Thank you! 😃

Indeed, I enjoy already beautiful weather ;-) Happy summer for you, too!

Maybe. But our windows are quite old...

Same transistor used for transmitter and receiver is called regenerative receiver.The transmitter is disturbed by an external object or signal and create a difference which can be demodulated. Very old way of building radios for pagers and remote control for boats and airplanes. Also built with tubes before WW2.

Oladunk is right. These are regenerative receivers. They are no more used these days. The chip does only the threshold and the timing.

I do not know. The car contains a lot of metal and maybe it interacts. You have to try.

@@AndreasSpiess Mate, you've the hardware there, how about giving it a crack and report the findings? If you find an easy/cheap option to do so, you might have a best seller video. I'm sure it find an wider interest than more than just our regular electronics cohort.

Thank you for sharing your experience!

Modern glazing contains thin metal covering to improve thermal reflection. Probably it is also shielding radio waves.

Danke!

That would be cool!

The IC has nothing to do with the RF. It is only a logic chip. They’re is Alyson no TX and RX because it only has one transistor. It seems to be a regenerative receiver (once famous in the valve age).

@@AndreasSpiess Presumably the IC isn't there just for decoration? Somehow it must be in touch with the RF section to know what is going on so it can do useful things like turn on and off. I'm not a radiohead, so technically RX and TX may be the wrong terms. My intended meaning though is a mixture of the transmitted signal and the reflected signal have been combined to make a much lower frequency beat signal. I believe that goes into opamps integrated into the IC for amplification and that is where I tapped in. How all that happens is black witchcraft as far as my understanding goes but I believe I'm at least approximately right about what shows up after amplification. One way I wonder if I could have been tricked by the witch is perhaps I was seeing into the middle of some magic the IC does to do what it does and it just happened to look a hell of a lot like it responding in an analog like way to speed or distance. For instance, maybe if what it is working with from the RF section isn't strong enough, it tries again sooner and sooner the weaker it is. received I'm in the middle of a project at the moment but I'll try to make time tonight to repeat what I did and get back to you with better details.

@@karlharvymarx2650 The IC has a function. It detects a threshold and does the timing. That is all. It is also used in most PIR sensors

I agree with your statements. These sensors can be triggered by close enough WiFi antennas.

I will. Today, we had 36 degrees in Switzerland…

The newer ones work on 24GHz (I made a video about one)

I agree. However, ours is pretty old.

I included a link for this product (Bangood does not sell it anymore)

Interesting project! Indeed, the ESP32 is much faster than any Arduino. But if I remember right: The Nextions internally work on 3.3V. So pay attention to 5V at the data line (you can easily test if you measure the voltage at the TX pin of the Nextion). If it is only 3.3V, the logic is 3.3V

@@AndreasSpiess Here's the thing with the Nextion. If using RX/TX lines at 3.3V, it seems to be hit or miss. With one test with ESP32 where I set baud to a staggering 921000, when directly connected (3.3V) the Nextion was glitchy. But when I used a logic converter, the glitchy was gone. To test at a high speed like that, I just have an animated picture (it's just a silly eyeball that looks all over the place) and I update the picture element number directly from the ESP32. Of course, we'd never do that with any other animations, but for testing, it's great, because at these crazy speeds, if there's glitching, I notice it right away. That test has been running for months now and has been solid. That screen was a 3.2" Enhanced (I think it is). But on the other hand, I used a different Nextion and at 3.3V (no logic converter to 5V) is just works fine. On that one, as a test I twisted the Rx/Tx sires together and then wound a ground over them. I put a ferrite core on it as well. That seems to work. I've used Nextion displays for years now, on Android. i only got into ESP32 boards a bit over a year (or 2???) ago. LOL (time is flying by). All-in-all, I really love these ESP32 boards and any "big" projects, I use those. You might sense that I really REALLY like Nextion displays. LOL

*Sorry, this got very long* Ooops! ✨😅😂🤣✨ I should have been a bit clearer on Rx/Tx communications when at 3.3V. I totally forgot about this yesterday, but remembered later on. When I was running into glitching with the Nextion, I did some experimenting. I always ran the Nextion with a baud of 115200 (with Arduinos). But with the ESP32, without using logic level converters (just 3.3V) the Nextion was super glitchy and more often than not, not responding well or at all. So as a test, I lowered the baud to 9600 baud. The Nextion was more stable. But my projects require high speed (as much as possible). So I added a logic level converter and a solid, 5V supply to that and converted ESP32's 3.3v logic to 5V logic lines. At 115200 baud, now communications were solid again. All of my Nextion displays are updated to Firmware 1.06.2 (or .3). When I uploaded my tests, I noticed that there were a lot more Baud rate options! The top one being 921600! INSANE! The uploads were so fast now and no glitching. (when uploading via USB-UART) So for fun, I set the ESP32 to that baud rate, with the logic level converters, to see if the Nextion and the logic level converter could handle it. It worked, but I did notice some glitching. Knowing that there was NO glitching while uploading the Nextion with my HMI, I knew that the display can handle that speed easily. So I figured that it had to be either the ESP32 or the Logic Level Convert. But knowing networking, I decided to twist the RX/TX (blue/yellow) wires together, then take the ground and wrap that around those wires. I added a ferrite core. As hoped, this solved the glitching issue! I set up 3 ESP32 devices to use Peer-to-Peer (broadcast) mode and have 2 of them send temperature and humidity to the "receiver" version. For testing, on each unit, I have the ESP32 send a very fast picture numbers to animate something in real time, fast. (just for testing). All worked perfectly, no glitching and I've left this running for several months now. No issues. So, crazy baud of 921600 does work well, with Nextion, using logic level converters and twisted cable. By the way, I LOVE these Nextion displays. It's fun to design really cool looking displays, using graphics, animations, buttons, etc. all inside the Nextion. It relieves the controller of most work.

Thank you!

I do not think so.