#291

[@SteveWrightNZ]

Just wanted to also say thank you for your engagement at a high level. Very nice to listen to a radio engineer talk about RF things, and you also do a good thing for all Radio groups of people. Thanks again.

[@AndreasSpiess]

Unfortunately my knowledge in RF is limited. I am mainly a ham with some experience. But no profund knowledge :-(

[@SteveWrightNZ]

@@AndreasSpiess You do very well. People love you for it.

[@mohamedayaan7802]

i dont mean to be off topic but does someone know a method to log back into an Instagram account?? I stupidly forgot my password. I would appreciate any help you can offer me!

[@davidbrody307]

@Mohamed Ayaan Instablaster =)

[@mohamedayaan7802]

@David Brody Thanks so much for your reply. I got to the site on google and I'm in the hacking process atm. Seems to take quite some time so I will reply here later with my results.

[@adrianstephens56]

Hello Andreas. I like your videos, and have given a thumbs-up to this. Full of practical advice. I worked on developing 802.11 for many years (from before it was called Wi-Fi), and it's good to see that it is now in the hands of the maker community. My one-time boss had an internet connection in about 2002 which was plain 802.11b using directional antennas (dish) over about 10 miles. It's amazing that the unmodified protocol works in those conditions - something it was never designed for. There were subsequent protocol changes (little used, as far as I can tell) to enable an AP and its client STAs to increase the slot duration so that CSMA/CA contention-based channel access continues to work with the same efficiency.

[@AndreasSpiess]

Thanks for your info. I might try it again because I now have A1,2m dish for 2.4 GHz Setup for QO-100. it has a reach of 36000 km ;-)

[@ajaybnl]

Now i understand having High Cost RF Measuring device, make your community Smarter in the field. *Thank You Mr. Andreas*

[@AndreasSpiess]

You are welcome. Not everybody has to spend the money. I sometimes also do not have the appropriate instruments.

[@krzysztofsoja5301]

Found it useful and (very) interesting. Thank You! Can't wait for the helical wifi antenna 😉

[@AndreasSpiess]

You are welcome!

[@WoLpH]

Thank you for the clear and simple explanation about dB/dBm/dBi. I finally understand how they work now :)

[@AndreasSpiess]

You are welcome! It is easier than you think ;-)

[@JavierChiappa]

@@AndreasSpiess Thanks, i knew there was a table to convert dB to sane-people units of measure like Watts

[@your-digital-bodyguard]

Andreas, as always, your videos, your in-depth knowledge and your humour is so much appreciated here. Thank you from the team at empower-iot.

[@AndreasSpiess]

Glad to read that! You are welcome!

[@KAtergorie]

It’s crazy how I often have some random question about anything regarding microcontrollers and then you have already made a video about it 😊

[@AndreasSpiess]

That is a comment I already got a few times. Indeed, this is strange ;-)

[@sblop]

Thanks for another great video explaining in depth complicated topics in a easy to understand way.

[@AndreasSpiess]

You are welcome!

[@valcob6617]

Damn it, how do I skip the next week straight to Sunday now?? Thanks for sharing this, as always my fav Sunday morning channel to watch :)

[@AndreasSpiess]

You are very kind! Thank you.

[@lluisllimargas2637]

Very interesting Mr. Spiess. Time management between digital data packet transmissions is a subject definetely worth taking into account when working in long-distance optimisation. Reducing data rate is an option, but leaving time to spread data between packets is another option. For example, GSM/2G standard technology introduced 'Time Advance' variable in packet transmissions in the 80's. And not to mention when the receiver or the transmitter are not fixed but moving to a relative speed one from the other.

[@AndreasSpiess]

Maybe this is a part of the patent. It seems that it covers also the topic of being compliant with the other WiFi signals that this mode does not conflict with other WiFi traffic.

[@souzamce]

You are the best! Thanks from your followers here in Brazil.

[@AndreasSpiess]

You are welcome!

[@alexnik8334]

After changing internal antenna to external You need to match impedance with ESP32 ANT. There is few components near that resistor, they are calculated to match impedance with internal antenna, since manufacturer knows, antenna is always same. To get best result with another antenna, you need to match impedance with ESP32 ANT pin or You will get what You've got in that video.

[@AndreasSpiess]

The antenna impedance on the connector should be 50 ohms. The manufacturer should take care about that. I cannot test it, but I can see how much of the 20 dBm get to the Spectrum analyzer. The rest is lost or reflected.

[@alexnik8334]

@@AndreasSpiess esp32 design guidelines topic 2.1.5 RF (CLC matching network) espressif.com/sites/default/files/documentation/esp32_hardware_design_guidelines_en.pdf Note: The parameters of the components in the matching network are subject to the actual antenna and PCB layout.

[@jemo_hack]

Alex Nik to be fair, from what gather, his comments are correct as they relate to PCB part that he is testing, so the Espessif document, while correct is a clear indication that those making the PCB with the external antenna are failing to follow the guidelines to provide for a better product, hence the result expresses by @Andreas Spiess.

[@alexnik8334]

@@jemo_hack Reading design guideline will point You to ESP32 Ant pin parameters: The output impedance of the RF pins of ESP32 (QFN 6*6) and ESP32 (QFN 5*5) are (30+j10) Ω and (35+j10) Ω, respectively. 30Ohm +10Ohm imaginary. 50Ohm antenna impedance will not match with ESP32 pin, since pin impedance less then 50Ohm. Impedance matching is very important. P.S I'm sure after splitting signal between antenna and oscilloscope, even antenna impedance + cable impedance is not equal to 50Ohm anymore.

[@alexnik8334]

@@jemo_hack I'm not arguing, just giving answer to question why external antenna works bad in comparison with internal "crap PCB Antenna". Only one reason for that is impedance mismatch, this makes attenuation much bigger of additional antenna gain, so signal partially lost.

[@ambarkulkarni2772]

You are the best! Bob Ross of electronics.

[@AndreasSpiess]

:-)

[@technologeando]

Why there is people who dislikes this video? This video is great. I'm waiting for the second part

[@AndreasSpiess]

There are always the same amount of dislikes quite early when the video is uploaded. I must have some "nice friends" ;-)

[@oleeide9763]

Again you manage to make a difficult topic understandable, thanks for another useful and interesting video. And now comes the hard wait for the next episode, pure HBO style, not releasing all the episodes of GTO at the same time.. The wait the hard wait...

[@AndreasSpiess]

Sorry for that. But long videos are not watched to the end :-(

[@guywhoknows]

I did research into this "issue" 16 years ago. Using two "systems", to boost range, we used higher Rx while using the maximum tx. The rules are as you say, but the maximum output is at the antenna. When the hardware is made it is often calculated in individual ways per manufacturers. Some built at antenna, others intermediate while selling a range of antenna... But the losses are not normally counted. This meant that if you mixed brands and hardware you could go over the legal limits quiet easy. For example A has a chip output of 1w, the antenna is 6w B has a chip of 6w and a antenna of 1w... I had regulated outputs, so was able to make antenna, we tested for up to 35 miles. What was interesting was that close connection "handshakes" kept the connection further that trying to establish a connection further away. (Adjustments were made to allow this).

[@AndreasSpiess]

The law usually limits the radiated power at the antenna and you are not allowed to change antennas. So your method works, but is not legal in most of the countries. This is BTW the reason they invented the "RP" SMA connectors: To make it difficult to attach a different antenna to access points...

[@walidboumediene900]

I adore your videos, Thank you so much for clearing that up

[@AndreasSpiess]

Glad you like them!

[@PeterCCamilleri]

Excellent! Very informative! I was not aware that the rules were so strict regarding antenna use for higher gain.

[@AndreasSpiess]

Rules are always strict ;-) Sometimes not enforced as strict...

[@ChrisMuncy]

NOOOO!!!!!!! You can't leave us hanging for part 2!

[@AndreasSpiess]

I have to. :-(

[@LarryKapp1]

Chris - I already saw it - just become a patreon of Andreas and you get to see his videos early

[@dgillies5420]

Its important to mention that most antennas are dipole antennas which means they are intended to point straight up, and they radiate almost nothing vertically or into the ground - almost all power is radiated horizontally in a doughtnut shape.. That way, the signal spreads over an area more like a disc (vs. a sphere), so the losses are proportional to r^2 rather than r^3.

[@AndreasSpiess]

Thank you for your information!

[@kokoscom]

Nice introduction Andreas. Looking forward for the next video. EU i believe we have ETSI regulations (100mW, 20 dbm) combined transmitter db + antenna db. In any case I usually prefer to transmit relatively low power from the transmitter, have almost no cable and minimal connector loss, and of course high quality antenna at the receiver end. In any case we always work with transceivers... so both ends are important along with the Channels available (having less noise) and also LOS is really really important and of course interference from nearby equipment.. Aircondition, motors, badly designed microwave ovens etc

[@diyemc7206]

It's actually EN 300 328 ... ask Google for the doc - they're free to download from the ETSI website. 73

[@AndreasSpiess]

The antenna is included in the calculation (ERP or EIRP). However I am not sure if they measure with a isotropic antenna (which is hard to build) or if they use a dipol or similar. In the next video I will use a unidirectional sketch which could be used to transfer sensor data, for example.

[@diyemc7206]

@@AndreasSpiessThe procedures should be in EN 300 328. The fcc procedures should be similar. However, iirc they're not identical. Radiated power is usually measured with calibrated antennas. The isotropic values are calculated from the calibration data. I built a measurement system for antenna patterns in a very, very basic way. If you want to collaborate on that... 73

[@markspc1]

Excellent video, Andreas !

[@AndreasSpiess]

Thank you!

[@giannismarkidis9546]

Perfect video. Hello from Greece !!

[@AndreasSpiess]

Thank you!

[@georgekot6377]

Looking forward to next weeks video !!! Thank you.

[@AndreasSpiess]

You are welcome!

[@RSP13]

Such an important video. Thanks

[@AndreasSpiess]

You are welcome!

[@mairswartz]

As always, super informative and interesting. Thanks. I'm looking forward to the next one

[@AndreasSpiess]

You are welcome! Only one day to wait ;-)

[@valdisblack1541]

Cool: build an antenna video! Can you add the "bisquare" and "roundyagi" to the comparison? They are simple to build. I can give you a link to the blueprints of those antennas. All you need is 2.5mm2 wires, bolts and ~0.1-0.2 foil.

[@AndreasSpiess]

As I mentioned: The video is already produced. It will only cover the two antennas shown here. But you will find a link to another channel which is focused on antennas.

[@yoctoflop]

@@AndreasSpiess Would that person happen to be Andrew McNeil?

[@DustinWatts]

Thanks for this video Andreas! Danke ;) The European regulations can be found in: EN 300 328.

[@AndreasSpiess]

Thank you for the link. I looked a little into the document but did not find information about antenna gain. But maybe it is hidden somewhere. Do you have information about it?

[@DustinWatts]

​@@AndreasSpiess Two quotes from page 29: "The RF output power for non-FHSS equipment shall be equal to or less than 20 dBm." and "This limit shall apply for any combination of power level and intended antenna assembly.". Another very informative article about the ETSI standard is this one: wlan1nde.wordpress.com/2014/11/26/wlan-maximum-transmission-power-etsi/ So the same as the FCC's 20dBm.

[@Fred_Klingon]

Wow! Thanks for sharing this valuable information!

[@AndreasSpiess]

My pleasure!

[@zaidhussain5206]

Thank you so much for this lecture , very informative

[@AndreasSpiess]

You are welcome!

[@WacKEDmaN]

very nice Mr Spiess!..im looking forward to the next part... i was thinking about making a few "pringle can" antenna's for extra range...

[@AndreasSpiess]

There are many designs available. I chose the helical because it was not covered a lot.

[@RakshithPrakash]

This is exactly wanted to learn

[@AndreasSpiess]

:-)

[@Kuba_kubowy]

Waiting for second part!

[@AndreasSpiess]

:-)

[@michaelkaiser6712]

Hallo Herr Spiess! Ich hoffe Sie haben trotz dem netten Schweizer Akzent das Deutsch noch nicht ganz verlernt. Ich liebe ihre sibirische? Katze vom Abspann, gruss von meinem sibirischen Kater Candy. Leider habe ich das englische nicht so drauf wie Sie, kompliment für Ihr Schweizer Englisch und Ihren tollen Kanal. Ich habe noch keinen KZbin Kanal gefunden in dem ich so präzise Erklärungen zu diesen hochtechnischen Themen gehört habe. Bitte weiter so! Grüße von Michael aus Deutschland.

[@AndreasSpiess]

Hallo Michael, wir sind hier alle per Du... Ob Dishka sibirisch oder einfach eine hübsche Mischung ist, wissen wir nicht. Sie kommt aus dem Tierheim. Aber sie ist sehr anhänglich. Betreffend dem Englischen: Da ärgere ich mich, dass man in der Schule nicht mehr macht (gemacht hat). Als Kind hätte ich es einfacher gelernt als als Erwachsener.

[@matneu27]

In the 80 s when I was a young boy my father was infected by the CB virus and used to drive at some evenings on a near mountain. Back home he reported that he heard other CB owners from Italy. (We live in Germany, close to France and Switzerland) At least his motto was : The best antenna amplifier is a good antenna! Now I am an old fart and wonder how to get my turtle shed in the remote yard online? Thanks to your videos I will find a solution 👍

[@AndreasSpiess]

I was also talking to the Italians back in the 70s on CB. I think we exaggerated the need for power. Even today many amateur operators use so called QRP transmitters with low power to bridge large distances. Maybe you have a look at this project: wsprnet.org/drupal/

[@zolatanaffa87]

@ matneu27: with SSB modulation you cover unimaginable distances compared to FM or AM. I participated in connections on 27 MHZ CB band with perfect reception, with less than 5 W at distances of about 600 KM and beyond with a GP ¼ λ antenna on a roof at 4 m ASL

[@avejst]

Impressive job you have done as always Thanks for sharing this great video👍😀

[@AndreasSpiess]

You are welcome!

[@hidayathmydin4676]

Hi Andreas, Many thanks for your RF Tech info.. simply explained & very useful. 😂👍 Kindly give us video on 2.4GHZ or 5GHZ DIY Antenna and simple RF front end using single transistor..

[@AndreasSpiess]

You will find the two antennas shown here and a link to a specialized channel. Adding RF front ends is not easy for a transceiver (transmit and receive).

[@hidayathmydin4676]

@@AndreasSpiess Thankyou very much Andreas. Your effort much appreciated sir. 👍😊.

[@magnetiseur77]

As user of hyper frequencies (my job), I often solder coaxial antenna cable near the source shorter as possible and with good coaxial (UT85). Cutting PCB line. This will improve power because these PCB are FR4 and we know this is very lossly. regards F1SLU

[@AndreasSpiess]

You are right. However, the traces on these modules fortunately are not too long. Other influences are probably bigger.

[@v-king936]

@@AndreasSpiess I found the PCB trace to the uFL connector on the shown TTGO board very long, though. And you are right to remind us to keep an eye on different versions of the same board, as you show at 10:53 in your video, Andreas. I noticed that my only copy of the first version (white switch and no labeling) has both PCB-antenna and uFL jack connected, as in the schematic. All my boards of the later version (labeled T7v1.3 and black switch) have no more 0ohms resistor to the external antenna. Thanks again and keep up the good work!

[@SamFugarino]

You must be reading my mind. Thanks Andreas!

[@AndreasSpiess]

You are welcome!

[@kilohertz684]

Another excellent video, thank you! I have a question re: ESPnow, there is the ability to extract RSSI info from the data stream, and as both of us are hams and enjoy antenna construction, it would be very useful to get that RSSI data out of the ESPnow stream. I am wondering if you have tried this yet? I have searched and have found snippets of code and some ideas, but I can't get anything to work, coding is not my strength, hardware is. 🙄 Maybe a topic for a future video?? Please and thanks.

[@AndreasSpiess]

I never tried. But search for "esp-now/src/espnow/include/espnow.h"

[@georgiychernov3967]

Thank you very much for this information.

[@AndreasSpiess]

You are welcome!

[@JuliusUnscripted]

"...before your 10th coffee in the morning" haha :D

[@axelmagnusmansson3265]

By far the worst dilemma when it comes to soldering

[@jonathanpayne9956]

@@axelmagnusmansson3265 worse than lead free? or seeing that solder pad stuck to the end of you iron after the nth modification!

[@KieranShort]

it's true... i tried soldering a pair of parallel 1mm long smd resistors last week, and soldering a 3mm square smd LED balancing on top of the resistor terminals. I reckon the sniff of a coffee is enough.. holy moly. I used a regular soldering iron. The flux saved me.

[@TuttleScott]

forget trying to move that zero ohm link, just wipe it off and then drag a bead of solder acrossed the other. problem solved.

[@axelmagnusmansson3265]

@@jonathanpayne9956 please don't mention lead free on this channel. Ixnay!

[@SchmurtzAlex]

Very nice, looking forward the next one ! 🤔 I hope that the result will be interesting !

[@AndreasSpiess]

Maybe also disappointing? Could be a possibility.

[@SchmurtzAlex]

Andreas Spiess yes it could be 😅 If wifi with low data rate could be extraordinary then Lora wouldn't be so interesting for our projects. Looking forward the results 😁

[@edgarmondragon4708]

WiFi is a Collision Avoidance protocol. It requires nodes to aknowledge all the packets that the AP sent. The AP also sends regularly polling packets to "ask" nodes about its presence in the network. If a node does not acknowledges its presence in the network for a standard-defined timeout period, the AP unregisters this node. Because the propagation speed of the waves is known, this timeout parameter is proportional to the range. This is the real range limitation of WiFi and this is why you can't simply increase the transmission power and achieve longer ranges. Some APs allow you to change these parameters and this is why you can connect them in P2P links. I worked in a Wireless ISP in the 2000s and we used WiFi modified routers to maintain a Metro Area Network. So I suspect the Espressif "proprietary protocol" is basically a WiFi standard tuning of some parameters to allow bigger timeouts. Of course, we can't know because the Espressif's WIFi implementation is closed source. PS The main problem of maintaining the WMAN was the interference. It is a very difficult task to maintain stable links in a metro area using a license-free overused band.

[@AndreasSpiess]

I did not dig into the details of the protocol. But in my setup the receiving sketch did not transmit power (as seen by the Spectrum Analyzer). And the patent talks about making sure that the signals are „heard“ by normal routers.

[@NicksStuff]

I thought the transmitting power was limited to 100 mW in Europe

[@AndreasSpiess]

I do not know the actual value. Adding antennas anyway is forbidden :-(

[@ed.puckett]

... before your tenth coffee... I love your sense of humor!

[@AndreasSpiess]

Thank you!

[@kristofers6559]

Great video!

[@AndreasSpiess]

Thank you!

[@KevinMartinez-ti7iq]

Hi Andreas, at 2:45 why does the +6dB will double the distance? If +3dB doubles the output power it should double the distance. +6dB should make the distance X4.

[@AndreasSpiess]

Hier ist eine bildliche Erklärung www.quora.com/How-does-sound-volume-decrease-as-a-function-of-distance

[@KevinMartinez-ti7iq]

@@AndreasSpiess You are right! There is a difference in double the power and double the distance. When calculating FSL the loss by distance is 20 x LOG[10](d), I got confused with the conversion from linear to dB which is 10 x LOG[10](p2/p1) and when p2 is double p1 it is +3dB. Thanks Andreas :)

[@armorfid]

*ESP32-CAM* boards come with an ANT connector and a 0-ohm resistor to choose between onboard or external. They even have a built-in microSD slot, and some ESP32-CAM kits include the external antenna itself. Edit: Also, *ESP32-WROOM-32U* boards have full GPIOs with a factory-soldered ANT connector and no onboard antenna.

[@AndreasSpiess]

If you need a cam and an SD card you are right. In the other cases you probably miss the blocked GPIOs...

[@armorfid]

The other GPIO can be accessed with wires soldered to the module, otherwise the SparkFun Thing Plus ESP32 WROOM U.FL is also a solid board specifically designed for external antenna and with plenty GPIOs. Most Chinese boards are really a lottery regarding the ANT connector. ESP32-CAM seems to be the most consistent one I've come across yet that has a factory-soldered connector.

[@armorfid]

Another good option for Amazon, *ESP32-WROOM-32U* (emphasis on the U) boards have full GPIOs with a factory-soldered ANT connector and no onboard antenna.

[@macroy007]

Very interesting. Go for putting two extra pins on it!

[@wduraes]

Great topic Andreas!!! but I must say that coffee or no coffee, I wouldn't be able to manage those 0201 parts :-(

[@AndreasSpiess]

I tried it with a thin wire because my smallest resistors are 0805. it took some time. Maybe you can only place a solder blob.

[@BerndFelsche]

Speaking of antennas, I forgot to ask on the SDR video about suitable antenna arrangements for very wide band application. e.g. 100kHz to 5GHz. Maybe a topic for future video.

[@AndreasSpiess]

Maybe. But for sure not beginning at 100 kHz. Maybe you calculate lambda/4 for that frequency. We have only small properties here ;-) I have some log-per antennas here and might show it once.

[@haajee1]

I was looking for the same and ordered yesterday a mini whip antenna from Aliexpress for my SDR. but a standard SDR goes to 1.7GHz I thought

[@AtomkeySinclair]

Fantastic! I wonder if there is a way to use the external antenna port as an input to the pcb antenna (disconnect the pcb antenna from the circuit) so you can test just the on-board antenna all by itself... ?

[@AndreasSpiess]

Maybe you can do that. But which problem would it solve? We still would not know the impedance of the chip nor the network used to match this impedance to the antenna.

[@AtomkeySinclair]

@@AndreasSpiess I had to watch again. I suppose I misunderstood the reasoning behind testing the open connector. I thought perhaps you wanted to evaluate how to use it, not how to avoid it and use the pcb antenna without any loss. And I figured being able to isolate the pcb antenna for direct testing was an approach for part of that. On second examination you were simply instructing us on how to identify well planned boards and their implementation in regards to effective dbm for use with and without the external antenna connector.

[@albertox0404]

Hi Andreas, Great video like always, do you know about any proyecto like Great Scotts Walkie Talkie but using Esp32 over WiFi or EspNow?

[@AndreasSpiess]

The reach would not be satisfactory, I think. And it would behave very similar to the one Great Scott and myself showed.

[@electronic7979]

👍

[@AndreasSpiess]

:-)

[@georgeprout42]

I have never stopped a video so quickly, the opening image shows that you're going to be in my hometown next week! But then I saw the price of the tickets ☹️

[@AndreasSpiess]

I do not know the prices of the tickets. The speakers are definitely not the expensive part;-)

[@georgeprout42]

@@AndreasSpiess £50 per day plus booking fees. I would only be able to make it for the very end each day, so sorry that we cannot meet. However, if you are staying in Reading town centre and would like to meet for a beer then I'm buying 🍻

[@AndreasSpiess]

I had to go on to Hyderabad early the next morning :-(

[@OreilleGauche]

Thanks, I learned a lot. Great accent, not worse than mine!

[@AndreasSpiess]

You are welcome!

[@RogerGarrett]

What is the angular field of view, both horizontal and vertical, of the standard camera/lens?

[@laurinneff4304]

I didn‘t know you and instantly thought you‘re swiss because of your name and accent

[@josephteichman8102]

As you reduce the power while increasing the antenna gain staying within the FCC regulations, your EIRP will go up (in the direction of the main lobe of the antenna), so you do indeed increase the range.

[@AndreasSpiess]

FCC limits EIRP. Unfortunately.

[@ramradhakrishnan9382]

Andreas! Thank you so much for a clear presentation - I am in the process of building a GPS/MPU/ESP32 board to be used a flight (more like, crash) recorder for my RC planes. Since they often land(?) among tall bushes I was planning to build a directionally sensitive antenna for the ground receiver - not sure if some of the "cantenna's" that I see on KZbin would be worth a try...

[@AndreasSpiess]

Most directional antennas are good for this task. Important is the speed you can read and display the RSSI values in the receiver. And here, WiFi is probably not the best. But maybe you find a sketch which sends packets in a very fast way.

[@ramradhakrishnan9382]

@@AndreasSpiess I have already tested this and found that even a simple WiFi Scanner sketch seems to do an adequate job of reporting the RSSI with minimum delay. I first tried to use the popular Android app: 'WifiAnalyzer' to sniff out my downed aircraft, but gave it up because of latency problems - it indicated a strong signal even after the transmitter was powered off, for several seconds - guess it was FIFO-ing the rssi data and reporting it late. So I switched to using an ESP8266 and an SSD1306 display to report the RSSI and seems to work well. However, when the receiver is very close to the plane ( say, 3 meters ) the signal strength maxes out, making it hard to pin the physical location easily - small R/C craft can be surprisingly hard to find in tall, dense vegetation even when you are almost on top of them! So, a directional antenna would definitely work well - I could walk a few feet away and triangulate.

[@TishSerg]

@@ramradhakrishnan9382 > when the receiver is very close to the plane ( say, 3 meters ) the signal strength maxes out, making it hard to pin the physical location easily - small R/C craft can be surprisingly hard to find in tall, dense vegetation even when you are almost on top of them! You could add a crash beeper, so when you're nearby you'll hear that. Optionally, you could add a feature of turning on beeper when you're already nearby if you don't want others to hear your RC plane before you get there.

[@mumbaiverve2307]

Is there a function or library to put the ESP32 in long range mode ? I don't think it is covered in the video ?

[@AndreasSpiess]

Maybe you did not watch till the end where I said: You find the links are in the description ;-)

[@mumbaiverve2307]

​@@AndreasSpiess Mea culpa ... :-)

[@transkryption]

Cool

[@AndreasSpiess]

:-)

[@vk3fbab]

Is 2.4GHz an amateur band in Switzerland? In Australia it is, so we could legally run 120w into any antenna. Probably way overkill but would allow you to run full 20dBm into 36dBi antenna. Just make sure you tx a call sign and don't use encryption. Ubuiti make commercial long range wifi. They had to hack some of the frame timings to allow greater than a certain number of km transmission. Wonder if you can do this in the ESP. Maybe you touch on this in part 2. Can't wait for part 2.

[@AndreasSpiess]

I think the first part is amateur band. But for the usage here it does not matter as we do not comply with many other regulations (call-sign, for example)

[@Frankie3sticks]

Great video, thank you

[@AndreasSpiess]

You are welcome!

[@johncrunk8038]

Thank you for investing in all of that high-cost gear. My bench is already full and my pockets are empty.

[@AndreasSpiess]

Same here with the bench and the wallet ;-) We call that "life" here.

[@robertcullipher3492]

To ensure a match from device to antenna, use a trans-match (impedance matching network) and to measure the reflecting power, put an SWR between the device and trans-match. Connect the antenna to the output of the trans-match. At these frequencies, the length of trace distance is actually adding inductive reactance, and if it isn’t the same loss on both external and PCB antenna, then this additional inductive reactance needs to be corrected. The easiest way to fix it is to place a small variable capacitor in parallel with the external connector and adjust until loss is a minimum. Finally, if you place a 50 ohm resistor at the connection, then this will give a perfect match at the antenna connection, though it is a terrible antenna. The benefit is that it will remove any additional reactance mismatch that the antenna might introduce. Do this while adjusting the capacitor or other trans-match until you have no reflection of power, and you will have successfully tuned the feedline(PCB trace) to the point of your resistor, or to the antenna connection. You could further do this to match an antenna that isn’t perfect, but such an adjustment would be specific to this exact setup, and may need readjustments when you change orientation, positions, locations etc. Simply ensuring that the device is perfect at the connector to the 50ohm impedance, then any changes is as a result of your antenna, and you have effectively removed the losses of the device (ESP/LoRa etc).

[@jlampe64]

Great video! BT and WiFi on the ESP32 use the same radio and antenna, right? So how all this influence on BT? The frequency is same, probably it won't be problem... Because of issues with WiFi and BT working in parallel, I am more keen to add additional external BT module.

[@AndreasSpiess]

You are right with BT and WiFi. All also applies to BLE.

[@abelpereira5043]

cool stuff, thanks

[@AndreasSpiess]

You are welcome!

[@leozendo3500]

When doing the calculations for the 2.4G band antenna, would you also include some info about the 5G band? There is very little information about that

[@AndreasSpiess]

The calculations are the same. But the manufacturing precision has to be better.

[@leozendo3500]

@@AndreasSpiess Thank you so much for your reply! I have been interested in creating a 5.1Ghz Wifi antenna that is more precisely engineered than just a soda can and a piece of wire.

[@lamjeri]

Just a side note. Even though it seems that increasing the antenna size on a transmitter is useless, as you have to reduce the TX power by the same margin in order to stay within the 20dBm EIRP, this is true only for oneway communication. If you use bi-directional communication, it is important to realize that antenna gain works for both directions, while TX power reduction (as it's name implies) affects only the output power. Unless it's forbidden by the law, using 20dBi antenna and 0dBm TX power on both sides yields a whopping +20dBm compared to 20dBm TX power and 0dBi antenna configuration.

[@AndreasSpiess]

You are right!

[@notDacian]

Very interesting stuff! :) I was wandering if this "Long-range" mode can also be used in the traditional ESP8266 or ESP8285 since it looks like a software hack of sorts? Sorry if the question was asked before, there are just to many comments...

[@AndreasSpiess]

AFAIK it is limited to the ESP32

[@notDacian]

@@AndreasSpiess thanks, maybe în the future we will see this also on the older models...

[@whitehoose]

Perfect synchronisation - I needed the information just at the time you chose to post it. There isn't a lot of info "out there" and it all conflicts with about 50% adding an extra antennae at the root end of the trace and leaving the track intact and of the other 50%, 25% solder aerial to far end of track to extend and the final 25% cutting the track and replacing the aerial with an alternative. There are also some inventive ideas involving dipole either separate or onboard. Whatever - all VV conflicting. I wanted to control the garage lights so I'm not advertising when I go out by lighting up the garage and street. Unfortunately the line of sight between router and garage includes the kitchen wall, the external wall of the house plus an extension utility room - so in total 4 load bearing solid walls making that area the most impenetrable spot on my plot! I have neither the time, kit nor interest to get very involved in the tech, nor do I really want to spend time and money extending my network and range extending the wifi into the garage just for a light. Worst case is I have to continue using a mechanical switch (aka carry on as is) and continue lighting the street when I go out at night. following Andreas' guide I experimented with; soldering a rat-tail to the end of the track -> seemed to reduce range. Moved tail to start of track -> mmmm not any great change. Finally cut the track approx 5mm from final component at the origin of the aerial to leave just the rat-tail connecting a short cheap wifi stick aerial from fleabay. While it's not a massive gain - the sonoff connected as soon as the external aerial was connected and consistently shows 2 of 5 bars (which is 2 more than any of the other options. So no surprise - Andreas is correct so far. While nor brilliant - it's good enough.

[@AndreasSpiess]

Checking if the antenna works in reality is always best! If you do not get stable connection maybe you want to change the modules to 433MHz, for example. Their reach usually is much longer.

[@whitehoose]

@@AndreasSpiess True! The sonoff units are good enough round the house to use as a party trick but have only very limited options to play with. Most of the time, it's easier to use the wall switch. Seemed like a good idea at the time. The link is up and as stable as can be expected. So I'm confident I've done it right - but signals are pretty mediocre, so you're right.

[@karte2626]

Great channel!!! Do you have any video about an analog isolator? That is, the input ranges from 0 to 5 volts and the output follows the range input 0 to 5 DCV. I appreciate!!!

[@AndreasSpiess]

No. I never had a need for that.

[@karte2626]

@@AndreasSpiess Thanks anyway.

[@gwc1410]

Do you have links to your dB and dBm charts?

[@AndreasSpiess]

I do no more remember which one I used. But if you take the formula you can create your own using Excel. Or google.

[@PHamster]

Is an isotropic antenna seen as a "Dot" in the middle of space or a "Wire"?

[@K9-33]

An isotropic antenna is theoretical and is used in antenna comparisons. It is a point in space which radiates equally in all directions like the sun, so it has no directivity. No directivity means 0dbi and any type of directivity will indicate gain. The gain of a real antenna is calculated as a comparison to the isotropic and is indicated with the dbi value. An antenna's gain compared to a dipole will have the units dbd. dbd = dbi -2.15.

[@soulrobotics]

regarding lines.... may i suggest to put everything in a box behind the antenna? provide power from battery and transmit data by other mean: cable, Bluetooth, IR ... but no lines(*). Nevertheless, the the length of the 50 ohms lines is not whatever length, it must be calculated.(*) i am referring to NOT USING COAX AT ALL, or only a very very short length.

[@AndreasSpiess]

You are right. I think I mentioned the fact.

[@ignaciolanzani6542]

Hi Andreas, do you know if this affects the BLE range?

[@AndreasSpiess]

I think so. Both use the same antenna

[@yogeshitaliya473]

Nice one sir

[@AndreasSpiess]

Thank you!

[@SteveWrightNZ]

It is possible one of your cables is acting as a transformer. Read about terminated vs unterminated quarter wave stubs - these have a fascinating behavior. It's very very easy to inadvertently make a quarter-wave stub at 2.4GHz, and partially or improperly terminating it will show all sorts of voodoo that will be very complex to realise into a coherant explanation. Your antenna analyser is very good at showing this - put a connector on some short piece of coax about a quarter wave on some chosen frequency and leave it open at the end. Put your meter in R mode (not X mode) so it behaves like an ohm meter and plot the frequency in question and you will see that your open circuit stub is in fact a dead short!!

[@AndreasSpiess]

The line towards the spectrum analyzer should be 50 ohms and a low VSWR. But the open connectors on the boards are stubs. This is why I think they will not help the performance. A quarter wavelength, however, is much longer than the lines to the connectors. So the influence is not clear to me without measuring.

[@AlWassmer]

will long range mode work on esp8266 and if so how to would be nice

[@AndreasSpiess]

No, it does not support it.

[@glorybeluan776]

Sir where we can buy this kind of antenna

[@AndreasSpiess]

One was DIY and one I got of ebay Germany. So I do not know.

[@donaldviszneki8251]

I've read that 0 dBm in radio and similar fields refers to the maximum power level that can be measured by the receiver or the maximum power level that can be transmitted by the transmitter. Is this so?

[@AndreasSpiess]

No. 0 dBm, as said, is 1 mW power. Transmitters usually transmit higher power and receivers are capable to detect much lower values.

[@donaldviszneki8251]

@@AndreasSpiess thanks. Is 0dBm always 1mw in all radio applications?

[@kirepudsje3743]

@@donaldviszneki8251 0 dBm is by definition 1 mW. The m indicates this: dB compared to 1m(W). You might be confused with dBc, which originally meant dB related to carrier, but is commonly used to refer to 'anything' with the highest value. E.g. a filter with a loss of say 2 dB and a stopband attenuation of 40 dB can also be stated as having a stopband attenuation of 38 dBc. Another example of dBc is e.g. harmonics, where the power is compared to the fundamental.

[@LutzSchafer]

Andreas, the ESP32 does not start transmitting just after powering up, or does it? I thought you need to have a connection e.g. to a router at the least so as to get it into transmitting? There might be a way to just turn on just the carrier, but how? Its likely all in the ESP datasheet, also which channel is chosen to transmit? Do you use some special Arduino code for this that you could share?

[@AndreasSpiess]

You should find all links in the description of the next video.

[@raguaviva]

veeeeeeeeeeery interesting indeed!!

[@AndreasSpiess]

:-)

[@jemo_hack]

Nice... I digging the spectrum analyzer, I think 🤔 I might get it! No sponsor link for that? 😉

[@AndreasSpiess]

I also had no Sponsor for that. But it was a long-term dream which I made true even before I started with KZbin.

[@WKfpv]

Is the same antenna used for Bluetooth?

[@AndreasSpiess]

Bluetooth and WiFi share the radio and, therefore, the antenna.

[@devluz]

Wow I never heard about such a high range with WiFi. I wonder how far this will get in less than ideal situations e.g. with a fence, a few trees or a building in between. This could make an interesting cat tracker

[@AndreasSpiess]

As you write: WiFi is not known for its long range. There are much better technologies around if you want longer range, but also less throughput.

[@jmaguilarr]

very interesting

[@AndreasSpiess]

Thank you!

[@BryanAbrilSar]

Can you send me the link where do you buy your osciloscope please

[@AndreasSpiess]

It was a special deal, directly with Keysight. So I have not link :-(

[@BryanAbrilSar]

@@AndreasSpiess I have a big question , where I can find a good IOT products to implemet in health , industrial bussiness can u send me the link there are a lot of places we have a company and we want to implement this kind of equip

[@BryanAbrilSar]

Please Answer me

[@zhuk462]

Are these antennas useful for BLE too?

[@AndreasSpiess]

Yes

[@jackm416]

As expected A+

[@AndreasSpiess]

Thank you!

[@madrian_hello]

Bluetooth on these boards is connected with the external antenna?

[@vincentstragier6628]

I think that they share the same antenna (maybe even the same modem).

[@AndreasSpiess]

They use the same antenna

[@RomanoPRODUCTION]

Wifi antenna makes the Swiss accent?

[@AndreasSpiess]

I do not know.

[@partscience]

That's very interesting!!! But (Also) make on that!!

[@AndreasSpiess]

:-)

[@MalagasOnFire]

thanks for the video.... 10th coffe ??? is an DSR problem :P Damn Small Resistors. Its good to know the LR feature on . Waiting to see next video , hope the power consumption can get reduced. watch out for the sleep modes of esp32

[@AndreasSpiess]

I will not use deep sleep because the focus of these videos were not on power consumption. But you should get the values. And then you can estimate your use case.

[@MalagasOnFire]

@@AndreasSpiess thanks for the reply. the idea was using this LR for some burst of information and doing some light / deep sleep mode while not transceiving data. it would be relying on the RTC for wake up . Here are some predictions for newer in this subject: lastminuteengineers.com/esp32-sleep-modes-power-consumption/

[@aboudezoa]

Hi Andreas , please make an episode on how to make 12 v power bank

[@noimnotarobotcanubeleiveit7024]

Did you know esp32s3 and c3 have a test mode that allows 80mw cw at 2.4ghz band for ec and fcc certification tests. Qo100 can just about hear that with a big tx dish.

[@AndreasSpiess]

No, I did not know this. I assume one of the problems would be to find it because of its inaccurate oscillator...

[@AndreasSpiess]

BTW: Do you know how to change the frequency to one in the range of the QO-100 uplink. I would like to test it ([e-mail])

[@EnergeticWaves]

good vid

[@AndreasSpiess]

Thank you!

[@partscience]

Sir great and I like that content but yet not too much for me!!! Please try to create on Tools, Industrial, Mechanical, create more detailed content on Lab Tours etc.... that's content is incredible and also carry that ON!!! But videos I'm looking for are no more!!! So, please!!! And at the end 😍😍😍

[@AndreasSpiess]

You are right, this is not a channel for beginners. But there are many other channels on KZbin.