#172

Today we will discover a hidden feature to connect two or more ESP32s or ESP8266s directly to each other: ESP-now. It is much faster and more energy efficient. And we will compare it to LoRa (RFM95 and Arduino Pro Mini.
Espressif gave us this possibility and, because it is so fast, they called it ESPnow. And it also works in the Arduino IDE.
In this video, we will
- Try to understand the difference between the standard ESP mode and ESPnow
- Build a working ESPnow connection for two ESP8266
- Check-out the transmission speed and
- Compare this speed with the speed if we connect the ESP to the internet
- Compare the Energy hunger of both modes
- And finally, compare the ESPs with another technology: LoRa
Links:
Sketches: github.com/SensorsIot/ESP-Now...
ESP-Now example: github.com/HarringayMakerSpac...
Not-rebooting gateway: github.com/HarringayMakerSpac...
Online Battery life calculator: battery-life.of-things.de/batt...
ESP32 board: bit.ly/2sOMR3E
Supporting Material and Blog Page: www.sensorsiot.org
Github: www.github.com/sensorsiot
If you want to support the channel and buy from Banggood use this link to start your shopping: bit.ly/2jAQEf4 (no additional charges for you)
Official Wemos Store: s.click.aliexpress.com/e/jUzBiIq
profile.php?...
/ spiessa
www.instructables.com/member/...
Please do not try to Email me or invite me on LinkedIn. These communication channels are reserved for my main job
If you want to buy me a coffee: www.paypal.me/AndreasSpiess

[@zachreyhelmberger894]

WOW! How come I only heard about ESP Now after all this time?! This is a major breakthrough in battery powered sensing!!

[@AndreasSpiess]

Good question. It is quite old stuff...

[@cliffchism9187]

Lol. 😂 i just heard about it this week.

[@StupidusMaximusTheFirst]

yeah, I too only heard about it recently... then again I'm clueless on electronics, I only recently started looking into them. ESP-NOW seems like a very simple peer to peer protocol, with emphasis on simplicity rather than interoperation everywhere like the TCP. There are good reasons TCP/IP is designed the way it is, but there're also good reasons to use something simple, fast, low-latency and nonstandard on certain applications. First time I hear of Lora as well, I suppose there's applications for this too. I suppose electronics people can easily build a dead simple transmitter/receiver and if they can also code, they can write their own simple protocols if they have specific needs. ESP-NOW seems like a good start for us newbies to play with and make stuff do stuff quickly.

[@RajveerSingh-vf7pr]

@@cliffchism9187 bro... I heard this week

[@RWB123]

I finally ordered a couple Esp32's after years of holding out. Your videos are bringing me up to speed on them and their features and quirks as quick as humanly possible. Thanks for saving me so much time!

[@AndreasSpiess]

You are welcome! And enjoy these wonderful chips.

[@johnlh100]

Watching your newest video became mandatory part of my sunday morning routine. Many thanks for this - again - useful and interesting episode!

[@AndreasSpiess]

Thank you for your feedback and welcome to the "Sunday Morning Club"!

[@hvanmegen]

#metoo :)

[@jimb032]

It's just not Sunday morning without Andreas and Great Scott! The videos are so well thought out and professional, I very much appreciate the time they put into them.

[@RTOHIO]

Using the examples, and following your instructions, I linked two ESP32 Dev boards together and communicated successfully via ESPNOW. You are one of the best teachers on the internet. Glad I subscribed long ago. Now I have to actually send some data packets of my data. Swiss accents are very nice.

[@AndreasSpiess]

Thank you and I am glad it worked for you!

[@MaxintRD]

Very interesting video. I didn't know about ESP-Now. Thanks!

[@AndreasSpiess]

I also learned just recently about it. And thought, it could be a nice addition

[@distancelab2010]

Thank you once again. Very interesting and gets me thinking of all the possibilities. I really appreciate the time and effort you put into your videos. Thank you.

[@bassome3000ify]

Richard Wilson Very true

[@AndreasSpiess]

Thank you! You like to watch the videos and I like to read all these nice comments during the whole Sunday! This is what we call win-win...

[@aveenof]

Thank you Andreas for your sharing your work to the community! It's exciting to think of the applications that can be made possible through the amazing ESP8266 chip as well as LoRa.

[@AndreasSpiess]

You are welcome!

[@colinpamplin9976]

Very interesting video and the ESP-Now concept (which I hadn't heard of) will be invaluable for my battery driven ESP8266/ESP32 devices.You could say it will transform it! Many thanks to taking the time to make this video and Seasons Greetings from the UK to you and your family

[@AndreasSpiess]

Thank you and also Merry Christmas!

[@jeffpollock5243]

Really like your videos Andreas! I am a novice learning and find that they have improved my learning better than any others. Thank you!

[@AndreasSpiess]

Nice to read. Thank you for your feedback!

[@jon_raymond]

Another great and informative video! Congrats Andreas on the very soon arrival of 50k subscriber's.

[@AndreasSpiess]

Maybe as a Christmas gift!

[@dgb5820]

I’m now asking myself why I have not watched all your videos. I’m grateful that you have taken so much effort into micro controller technology. I will now research about ESP32 now.

[@AndreasSpiess]

Enjoy the ESP32. It has very good features.

[@MrPinolatino]

Your contribution for us is invaluable! Thanks!

[@bassome3000ify]

Augusto Massaro True story Bro!

[@waltsteinchen]

Double that!!

[@AndreasSpiess]

Thanks, guys. You make my Sunday!

[@MeriaDuck]

The months december and january are designated for home automation and electronics, these were well timed videos. Thanks for pointing us to node-red and to this possibility!

[@AndreasSpiess]

You are welcome!

[@cymeriandesigns]

Andreas, you really are a treasure. Thank you for all the effort you put into each of these videos.

[@AndreasSpiess]

You are welcome!

[@aura-comms4633]

Thanks again Andreas, you are definitely the best companion for any project

[@AndreasSpiess]

Thank you!

[@rjmackenzie]

This is exactly what I wanted. I'll be implementing this on some marine monitors! Thanks for this vid.

[@AndreasSpiess]

You are welcome!

[@dmurphydrtc]

Excellent video, as always. Like most I wasn't aware of ESP-Now.

[@AndreasSpiess]

Thank you!

[@vaughan.gittel]

​@Andreas Spiess thanks for all your videos & effort

[@AndreasSpiess]

My pleasure!

[@olir.8125]

Ein aufwändig gemachtes Video, das einen tollen Überblick gibt ! Vielen Dank dafür ☺️

[@AndreasSpiess]

Gern geschehen!

[@bartgijsbers7373]

Thank you very much for pointing me in the direction of ESP-now. This is the step I needed to make battery sensors based on esp32/esp8266. I did wrote a esp-now to mqtt gateway on one esp8266 without problems... First init WiFi and then init espnow. I have them both active without any problems. BTW, I like your video's very much. Keep them comming.

[@AndreasSpiess]

Thanks for the feedback. Could you probably post your code somewhere for others to be used? Seems interesting.

[@peut]

I have tried it. It works for some time, with a round trip time measured on the sensor ( master ) node that is twice as large ( 17 vs. 4 ms). The sensor node does never receive an ack in the send callback function an error (1) is returned. Then, after about 8 messages, the WiFi node does not receive any moremessages. Of course, I may be doing something wrong. See github.com/gitpeut/try-espnow. To get this working I'll go for DualESP.

[@elesjuan]

This is most excellent. I'm working on putting together a home automation system using ESP8266's for various sensors and switch supervision. One of the issues I was running into was how to toggle several different lamps on and off. I really don't want to be tied to a smartphone, PC, or some sort of master control panel to toggle the reading lamp in my den on and off. One idea was battery powered "remote" but constant connection to wifi would kill the batteries in no time. With your ESPNow solution, I could setup an 8266 as a master/gateway to wifi and have several battery powered push buttons throughout the house.

[@AndreasSpiess]

You might also watch my videos (#101 and #108) on the dash buttons.

[@peekpt]

Wow! Mr. Spiess this is news! That looks really interesting. Thank you for this video, going to investigate more, looks promising!I can imagine the applications like mesh sensors for farmers, for preventing fires and so on...

[@AndreasSpiess]

Thanks for your feedback!

[@NotMarkKnopfler]

I'm not sold. The advantage of LoRa is it can transmit over very large distances, as famously proven by yourself in your incredible video where you transmit from France! ESP now, being based on WiFi radio will not have anything like the range. These are apples and oranges. It might be good, say, around the house for sensors; but for SCADA and telemetry (where I'm developing LoRa products) this isn't appropriate. It is very interesting though. These little devices are simply incredible! Thanks for the video Andreas. Warmest regards from Aberdeen, Scotland.

[@AndreasSpiess]

I think, your comment is a summary of my video. My last sentence was: "So, each of the three technologies has its perfect fit, but also areas where I would not use it. Maybe this video helped you a little to do the right decisions in your projects."

[@AndreasSpiess]

BTW: You are a great musician, too. I saw Mark Knopfler with Bob Dylan in Zurich. This was one of the best concerts ever. Because of Mark!

[@fjgarcia12]

It would be interesting to do a test to check the range of the esp in this mode.

[@NotMarkKnopfler]

Andreas Spiess Ha ha! Thank you!

[@joobasics6891]

Could I have the video link of this LoRa test? thank you

[@williammiller7543]

Great Video! I have been toying with having several sensors around the house but up to now I haven't seen a good way to handle it. I didn't want to get into LoRa, moe unique boards and new things to learn. I also am moving everything over to the ESP32 so this all fits for me. Thanks again.

[@AndreasSpiess]

You are welcome!

[@jps99]

Thanks, very well explained!

[@AndreasSpiess]

You are welcome!

[@johnward7619]

Thanks for this video, very insightful

[@AndreasSpiess]

Glad you enjoyed it!

[@nburton01]

Great video and very useful. Will solve a problem Ia'm having with a solar powered ESP32 project running out of power at this time of year. Was going to rebuild form scratch but using ESP-Now should hopefully solve the problem. Many thanks, keep up the good work.

[@AndreasSpiess]

Maybe it helps at least...

[@ICTlinkCentroMultitek]

Congratulations, excellent video.

[@ArseinLupin]

Very nice job Andreas as usual!

[@AndreasSpiess]

Thank you!

[@johnb1677]

Another great video Andreas, thanks!

[@AndreasSpiess]

You are welcome.

[@olir.8125]

Sehr gut gemachtes Video. Ich habe mir direkt einen Außentemperatur Sensor mit dem ESP-07 (mit Antenne) und einer Empfangsstation mit dem ESP12e mit Adafruit Display nachgebaut. Das ganze mit den Programmen von HarringayMakerspace. Funktioniert tadellos. Immer wieder erstaunlich was man mit den ESP8266 Modulen anfangen kann. Weiter so !

[@AndreasSpiess]

Deswegen haben diese Chips so viele Anhänger...

[@garrypkeogh]

I had heard but forgotten about this, thanks again Andreas! I went directly to Ali Ex to buy memory for my box of ESP01dev boards. This should enable OTA, free some GPIO and make for some super low power 'things' about the house. I see a commercial app too, many thanks again!

[@AndreasSpiess]

If you do not need lots of pins, the ESP-01 is still interesting...

[@Lamsadi]

thank you very much Mr Andreas

[@AndreasSpiess]

You are welcome!

[@bluefishactcl1464]

Very good again - lots of interesting information and relevant observation

[@AndreasSpiess]

Glad you enjoyed it

[@bluefishactcl1464]

@@AndreasSpiess If you have time I would like to hear ideas about measuring liquid pressure like the bear pressure - simple and reliable - I need to estimate water level in a elevated storage tank and pressure seem to be a simple way but could not find a simple transducer . Any way , thank you for time .

[@AndreasSpiess]

They sell pressure sensors on AliExpress. But I do not know if they fit your requirements. I searched with "Water Air Pressure Sensor"

[@bluefishactcl1464]

@@AndreasSpiess Using your hint I found one at Amazon that might work . Thank you

[@geoffcoucher3545]

Really helpful, thank you.

[@AndreasSpiess]

You are welcome!

[@ahmadx87]

It is becoming a habit for me to like your videos and then watch them.

[@AndreasSpiess]

Thank you for your support!

[@DrTune]

Very very useful thanks, terrific video

[@AndreasSpiess]

You are welcome!

[@chuxxsss]

Another great vlog Andreas.

[@AndreasSpiess]

Thank you!

[@faamp]

Great video! Thank you.

[@AndreasSpiess]

You are welcome!

[@jmaguilarr]

hi , an great video as always ! thx

[@AndreasSpiess]

You are welcome!

[@lbsfilm]

Incredible =D thanks for this really really cool videos

[@AndreasSpiess]

Thanks!

[@KJD783]

Thanks for all great videos! I experimented with the ESP8266 and ESPNow and WiFi and found that the WiFi channel selectivity of these is extremly limited. When signals are strong, the STA will easily connect to an AP on a neighboring channel and ESPNow transmissions sometimes get ack-ed on channels that are even further away. When a unit receives an ESP message that does not mean that the transmitter sent that on the same WiFi channel. That makes it hard to make an automatic channel selection by scanning for response (that and the issue that channel is not easy to control in STA mode). Obviously it gets better with more distance but the crosstalk easily reaches 10 meters or more. It also means that distance performance and your measurements probably get influenced by nearby transmissions. A strong signal from a nearbby transmitter even when on a different channel may have a large impact. What you did is a real life situation so it is a good indication of what can be expected, but it makes it probably not really reproducible, it is more an indication of what is to be expected. I wish RSSI was avaialble for ESPNow receptions and ack, that would help a lot. Now I get responses on multiple channels and have resorted to picking the center one where there is response. I haven't tried with a ESP32.

[@AndreasSpiess]

I was not aware that crosstalk can be demodulated. That is very strange behavior! Thanks for the info

[@uncleal6095]

Yes, Interesting. I find the RMS function of the oscilloscope useful for measurement of power in complex waveform events.

[@AndreasSpiess]

Good idea. So far, I never used it for such signals. Are you sure it will work with these small spikes?

[@NoProblem76]

Interesting! thanks for posting!

[@AndreasSpiess]

You are welcome!

[@bardenegri21]

Awesome video! Here's a project idea: many esp8266 devices connected via esp-now to a esp8266 master that has a serial connection to a raspberry pi. All messages from the esp-now nodes go through this serial connection to node red for automation tasks. That would mean you could skip mqtt completely if you only need esp-now nodes. Could be a unique network style.

[@AndreasSpiess]

This is definitely a better idea than the one I used if you have many sensors. I found a plan to add another ESP for MQTT. But your proposal is simpler. And if you use a Pi zero, also not too expensive.

[@bardenegri21]

I was thinking, there's one disadvantage with ESP-Now: you're relying on an ESP module to do all the receiving of signals. They usually have PCB antennas, except for the ESP-07, so range will probably not be as good as with a router. And with routers you can also have multiple routers serving the same WiFi network for really big spaces. Could be problematic when trying to cover a big house or yard with sensors. Would be nice if there was an ESP8266 or ESP32 based board that is focused on getting the best range, with a properly tuned external antenna and everything. Or if there was a way to have traditional hardware listen for ESP-Now messages (it should be doable, but I doubt there is software for it).

[@hollensted]

Crazy! I just calculated a 3 year lifetime when running on a 2600mAh 18650, sending data every hour. Work just got really fun.

[@AndreasSpiess]

:-)

[@joezybernatic7435]

very useful and great content.

[@AndreasSpiess]

Thank you!

[@gavinknight8560]

Fantastic video

[@AndreasSpiess]

Thank you!

[@alexandracrawford800]

Dear Andreas, as always your contribution is valued and highly valuable. In this case however I must comment on the continued usage of historical and outmoded references to "master" and "slave" as originating from a supremacist vocabulary. Recent similar discussions have remarked upon alternative functional terms (dependant upon context) as: "control vs remote vs return" & "origin vs target vs response" with: a common term of "message" referring to the data from the control or originating device & data sent back to the origin or control device being referred to as the "return or response" This not an exclusive list but is a starting point for memorable replacements with CRR & OTR mnemonics for non exclusive examples of "Comfort Requires Relaxation" and "Open Truths Refresh" Good Job Andreas!

[@AndreasSpiess]

Fortunately, we Swiss have no such history and our thinking is "clean". So I have no issue using these commonly accepted (in electronics) words.

[@alexandracrawford800]

en.m.wikipedia.org/wiki/Triangular_trade. I agree your national history and identity stand as exemplary and are iconic representations of neutrality. I do not think you would be drawn into any discussion to logically prove your outlook. However even Switzerland stands upon the shoulders of vast economic inputs from 400 years of lucrative triangular trade by Western European countries including the UK who are trying to avoid responsibility for the fallout from arms trading to the Middle East by exiting the European Union. Our histories are all based upon supremacist exploitation of an isolated peaceful continent and it's populations. Please reconsider your use of historically tainted and conceptually overloaded terms. Although you may say they are in use within an industry characterised by white males, the need to recognise seed concepts as a danger in the naive mind that has not yet grasped the functional concept of balance to establish self organizing neutrality. Such personalities are readily targeted by unbalanced supremacist personalities for their own gain. The symbols of national socialism circa 1930 Germany have been outlawed for similar good reason. Please show respect for the millions of personal tragedies created by the paired concepts of "slave" and "master". Non but ourselves can free our minds, but we can help each other. Thank you, Andreas

[@muhammadadeel1947]

very much informative......

[@AndreasSpiess]

Glad you think so!

[@05pamar]

Thanks, great video, very profesional!

[@AndreasSpiess]

Glad you liked it!

[@wjhoogervorst]

Thanks for again a great and inspiring video. As I read in the previous comments, it would be great to see an example were an ESP sends data to an ESP with a serial connection to a raspberry running node red.

[@AndreasSpiess]

Maybe I will do something like that, but I am not sure. Maybe somebody else will do it?

[@wjhoogervorst]

@@AndreasSpiess I did it myself, see www.instructables.com/id/ESP-NOW-Home-Automation-Esp8266-Raspberry-Pi-MQTT

[@axelmagnusmansson3265]

As always a great topic, that i didnt even know existed. All the news here on this channel! i think the big fight for this wonderful chip is now battery consumption ( a part from security, because my test show that more often than not, ESP32 crashes and locks at least once in a week, as weel as QoS). One sample per hour is not really my standard. Maybe a video putting all of our choices and the pros/cons comparison. BLE, LoRa, ESP now, Wifi (and other we dont yet know about?). Battery consumption (incl wake from sleep), range, bit rate, and QoS. Great work as always Andreas!

[@AndreasSpiess]

A lot of wishes... Maybe one day they become true ;-)

[@axelmagnusmansson3265]

yes and a lot of work, i know. but you have made most of the tests now. i was thinking the Big Recap of those. so maybe less work. anyway, whatever you do, i will follow! thx

[@PHILG2864]

Hi Andreas, very informative video, thank you Whilst there are plenty of examples of its use, I've spent a lot of time trying to find the ESP8266 library itself, it seems Github has many variations and function constructs and defines are different between different versions, with different people adding various arduino library wrappers. I've done quite a few 'Alexa' projects so I'm happy working with the esp8266 via WiFi, I use only the tiny ESP-01 boards, using the ESP extensions in the Arduino IDE and programmed via async serial. All work well. But I've been unable to compile anything at all for espnow! As yet I've not found anyone successfully using espnow on the ESP-01. If I could just get the simplest espnow example to compile I would be happy! Keep up the good work, the Lora videos were particularly helpful. Cheers :-) Phil

[@AndreasSpiess]

Maybe the flash memory is too small?

[@michaelbyron2321]

Andreass, you are my hero. I look forward to each of your episodes. Your style is flawless. Can you do some more on the" ESP Now" but with detailed range testing. This is of great interest to me. Will the range be the same for both the ESP8266 and teh ESP32?

[@AndreasSpiess]

I plan a video concerning ranges in the near future.

[@johncongerton7046]

Excellent, as always

[@AndreasSpiess]

Thanks!

[@brycedavey1252]

I would like to see a follow up video on rage :) Great video

[@AndreasSpiess]

I hope I will find the time in the next future...

[@zaceshadowz6158]

Jus Came To watch detail about esp-now but now im enlightened...

[@AndreasSpiess]

:-)

[@zaceshadowz6158]

@@AndreasSpiess Didn't thought it would be freaking detailed thank you very much for the hard work...

[@lordhelmchen100]

3:29 you meant http right? Also gr8 video btw. This was exactly what i needed for my current project :-)

[@AndreasSpiess]

I meant HTML but forgot HTTP.

[@debuggerau]

Thanks for sharing

[@AndreasSpiess]

You are welcome!

[@zoltanbauer2722]

I f-ing love your videos

[@AndreasSpiess]

Thank you!

[@adminspnetworkingirflabs8180]

Good one

[@AndreasSpiess]

Thank you!

[@kieranj67]

Thank you!!

[@AndreasSpiess]

You are welcome!

[@mairswartz]

Very very cool. Something worth trying might be to measure signal strength and create a mesh with multiple devices

[@hanstanner4639]

Like this? github.com/gmag11/painlessMesh

[@mairswartz]

Oh wow!. thats pretty cool. But I don't think it uses ESP now

[@hanstanner4639]

It does not, it forms a network with devices set to the same AP, even though the AP does not have to exist, just AP name and password must be the same.

[@mairswartz]

defiantly one to play around with

[@AndreasSpiess]

It seems, that Espressif also offers a mesh ( espressif.com/en/products/software/esp-mesh/overview )

[@dan2thi]

Awesome!

[@AndreasSpiess]

Thanks!

[@cavalier3920]

Andreas, thank you for leading me to Anthony Elder's code resulting in a 220 mS communication period and power savings. After your video was published he has offered an even lower-power alternative in espnow-sensor-minimal.ino that describes a 40 mS period. This uses a sleep function called "ESP.deepSleepInstant". After verifying that the receiver/sender pair worked with ESP.deepsleep() I had some trouble using deepSleepInstant. It seemed to be too fast in closing down - perhaps shutting down the radio before it was done. Later I found that my last Serial.print functions were missing. Inserting a delay(10) right before deepSleepInstant seemed to fix it. BUT THE BIG NEWS is that the measured time between "send" and the end of the callback function is averaging 100 mS. Not as fast as the advertised 40 mS, but still a big savings for the battery! Very un-powerful! Hope this helps your viewers.

[@AndreasSpiess]

Thanks for the info. Serial print takes some time. And if you place a sleep command after such a statement the info is no more sent out.

[@cavalier3920]

@@AndreasSpiess Yes, Serial.print takes time. And the same is true for other communication logic, I presume. I was thinking that the processor was thinking... do A, stop, then do B, stop, then do C. My error was thinking these ESP devices are 'single threaded' or not 'multi-tasking', however they are really multi-threaded and multi-tasking, because B can start before A has finished, I think I am experiencing. (Fortran N77 was my last class on the subject, long ago.) If the device is shut down before a transmission is completed (serial, or radio) then the transmission that was underway is not completed, right? For me that is a design discovery and an 'abstraction' convenience as it makes it easier for rookies like me. BTW: "cavalier 39" seems to be my default username when I have that gmail account open. My true identity is Craig Larson, a loyal patreon'ista. (I advise all Andreas fans to join Patreon and support the channel! Do your part!)

[@tejasarlimatti8420]

Thanks so much for another one of your wonderful videos! Btw, the SF7 most *definitely* must have higher range than the ESP8266's WiFi, right? I mean, WiFi can only go so far. Maybe 50, 100mts? SF7 I'm sure can go for kilometres, isn't that right?

[@AndreasSpiess]

+Tejas Arlimatti You are most probably right. But I will try it in another video.

[@gorally2003]

great video!! I am trying to do a point to point using esp32/esp8266 to send a temperature from a max6675 to another esp32/esp8266 to output to my nextion display or a tablet. Thanks for all your great videos

[@AndreasSpiess]

You are welcome and good luck! If you have a sketch with mixed ESP8266 and ESP32 it would be nice if you share it. I did not find one.

[@gorally2003]

Ok if i write one i will i hadnt decided if i'll use the esp8266 or esp32 or one of each I but I'll post a link to my git hub page as soon either fine wine or right one

[@pub_scrubs]

man, you're a godsend

[@AndreasSpiess]

:-)

[@MrJanulis]

Thanks, very informative! By the way, in case of "standard" ESP mode calculation you used 90mA, but in ESP Now - only 80mA. Was it intentional or just a mistyping?

[@AndreasSpiess]

I added a little for the many small spikes. For sure not accurate, but I am an engineer, not an accountant ;-)

[@sofianfadli7910]

Cools... You are very awesome,Andreass !!! Why you can understand many things and create videos that are very useful just in a week? Are you doing research every day in your life? I'm courious...

[@AndreasSpiess]

Yes, of course I work nearly every day and sometimes also the nights on my hobby. This keeps me young...

[@MudahnyaCoding]

thank very much...i'm from indonesia

[@AndreasSpiess]

You are welcome!

[@rklauco]

5 years later I learned something new...

[@AndreasSpiess]

Good to know :-)

[@mjj2u2]

One thing to consider is the significant difference in price between the ESP and the LoRa. Given the price difference I would pick the ESP every time especially since you need two for connections

[@AndreasSpiess]

:-)

[@hectormery605]

Vielen Dank aus T/ucson Az. USA

[@AndreasSpiess]

Gern geschehen!

[@hollensted]

Awesome. I have been thinking about how to send data between some of my sensors on esp's. I am just hoping one day that WPA2-enterprise will start to work on the eps's.

[@AndreasSpiess]

I am not a network specialist so I do not know the advantages of such an "enterprise" infrastructure (at least for a maker like me)

[@hollensted]

It's what they use on university's so that's why i am interested. I work at an university, and i would be able to "roam" with my login an all of campus.

[@AndreasSpiess]

Aha. That's what I thought.

[@mikebpetersen3027]

Love your video's - spot on! Quick Question on video #172: Can ESP-Now still communicate in "Station+AP" mode? Or is it one or the other.

[@Ed19601]

I understand it can be both.

[@adrianstephens56]

Interesting. I'd not come across this protocol before. I have to declare an interest as somebody who worked on the 802.11 standard. The protocol appears to use the 802.11 Vendor-specific action frame, which is a way to allow it to use its 802.11 hardware, but to achieve a proprietary protocol that won't inconvenience other users of the same band (because they will discard the packets). The issue for any low-power protocol is controlling who is awake to listen. The original 802.11 protocol (circa 1997) supports ad-hoc power saving. The essence of this is that devices share an approximate clock, and wake for a window during which their intent to communicate is declared. A device seeing it is an intended recipient stays awake until it is allowed to sleep. But this was not "fine-grained" like you need. I don't see any of this complexity in ESP-now. So I have to conclude that one of the two ESP nodes (in the role of controller) has to stay awake permanently to provide the other with the ability to wake, transmit, and sleep in short order. 802.11ah added "Target Wake Interval" to coordinate a network of such devices while maintaining network efficiency (something you may well lose if you just wake and transmit). In doing so, it was following a fine 802.11 tradition of adding "YAMIPSM" - yet another mutually incompatible power saving mechanism.

[@AndreasSpiess]

So far I did not see any implementation with both devices sleeping. Would be interesting, but not simple to make it stable, I assume. Usually the "gateway" is connected to mains.

[@jozefgoral6812]

Great material. He helped me a lot to understand the problem you raised in this episode. I'm currently doing a similar project in college. would you help me and recommend some internet sources or a book in which this topic is extended? I also want to encrypt my connection and get the maximum point-to-point speed possible.

[@AndreasSpiess]

You have to do the research yourself because I am not interested in security and therefore have no knowledge. Books are usually outdated before they are printed ;-)

[@sergheigarau514]

hello Andreas, many compliments, your videos are always very interesting !!! I wanted to use this ESPNOW technology for an outdoor application. But when I tested the sketches, I noticed that ESP32 heat a lot and this seems to me a big problem especially for the reason that some nodes would go in the box exposed to the sun and I can not install a fan ... I think that LoRa does not have this problem, what do you think?

[@AndreasSpiess]

LoRa transmitters use less power and heat up less. But the sun might be your real problem.

[@jobgreaves]

Andreas, Thanks for the informative videos about IOT gizmos. You mention the limit of 20 devices per node. If we add another Master kind of unit can we get another 20 devices? What about 3 or more Master devices? Not sure where the limitations come from. Also: You sound very much like a friend from Bern. You too?

[@AndreasSpiess]

AFAIK the limit is per device. If you add more devices, you can multiply this number. I think, most Swiss German speaking people have similar English accents...

[@doit1374]

Very nice video! Do you have an educated guess how the range would be of ESP-Now relative to WiFi range?

[@AndreasSpiess]

I assume it will be similar, but I plan a video to check.

[@eduardogodoy7621]

Andreas Spiess I am looking forward to see it!!! Thanks.

[@AndersJackson]

If you compare them, then you should use static IP, as you use static (MAC) address in the ESP-now. The data size for IP addresses are not a problem with the high transfer speed. ESP and LORA have much longer range. (ESP as it uses Internet, but have to have a router near).

[@AndreasSpiess]

1. Static MAC is not the same as static IP for me. My router does not like too many static IP addresses, so my limit is there. 2. I plan to do a comparison about the ranges

[@AndersJackson]

Static address are the same, what ever format they are in. As MAC address are the only address level for ESP-now, that is static addresses. IP dosen't actually care about MAC address, as that could be changed for the same MAC: That is different abstraction levels. With static IP, you don't need the negotiation time. Yes, that is a problem with small home routers.

[@dmurphydrtc]

Just a quick note as I have not seen much written on the ESP-Now topic. I have tested distance/range of 2 different types of ESP32 boards, DOIT Devkit V1 and a TTGO T7_V1.0. I used the scripts by "Harringay..." as listed above. No matter what combination of boards the greatest distance I could get between master and slave was approx.15m. My wifi distances were similar. Anyone else carry out measurements with different boards ? Ta.

[@unitechmarine8076]

Hi Andreas. You should explain the range difference in LoRa

[@AndreasSpiess]

I think I have many videos about the range of Lora. But I am planning a video about Range of Wi-Fi and BT

[@darkmatter5310]

Ver nice and clean explanation about ESP-Now; quick question can we read message stream with mobile phone in wilderness?

[@AndreasSpiess]

I do not think so. For wilderness project you might watch my meshtastic video

[@darkmatter5310]

@@AndreasSpiess Thanks a lot, that is exactly I was looking; you are always fantastic.

[@ProtoG42]

Cool! I used ESP-NOW in my ESP32 clock!

[@AndreasSpiess]

Now I watched your cool clock video!

[@1CM69]

Great video, very informative. What alterations are need to your Slave code in order to receive data from multiple Master units?

[@AndreasSpiess]

I do not know. Maybe Google knows more?

[@1CM69]

Thanks for replying, I found the answer shortly after my initial post. 👍🏻

[@olafkaus9826]

Hi Andreas, first: Thanks a lot for your detailed and interesting videos. Because the ESP32 also include Bluetooth, what is your opinion about a Bluetooth Mesh for Sensors? Especally in battery consumption. Thx, in advance Olli

[@AndreasSpiess]

I am no fan of mesh in general. If it would be useful, It would be used much more. In my opinion it is ok for a fe niches. BT only has a small reach.

[@CintraxBR]

Hi, great videos !!! For a 1-2km range which one would you use ? I have a small farm and would like to open and close water valves for the irrigation system. Thanks, Max

[@AndreasSpiess]

You can watch my videos on LoRa range. Wi-Fi is not made for big distances

[@drstefankrank]

I think for in home battery powered sensors using only the chip without the dev board and then using two wall powered esp connected via GPIO and some serial protocol as a gateway would be a good option. One esp does the ESP NOW stuff and the other is permanently connected to WiFi. With that you don't have to reboot after each message and can transfer much faster in both directions.

[@AndreasSpiess]

Maybe you are right. Just try it and you know ;-)

[@drstefankrank]

@@AndreasSpiess 4 bare esp32 were in the mail this morning. :)

[@HelmutTschemernjak]

Hello Andreas, thank you for the videos. Your comparison is not taking into account the following LoRa modem features: a) A bandwidth 250 kHz and 500 kHz is possible with the LoRa chips, you tested 125 kHz. This means basically 2 or 4 times less transmitting time, resulting into energy savings. b) LoRa sending power can be adjusted between 2dBm and 20 dBm, I assume you tested with 14 dBm. To compare it with the ESP 2.4 GHz range, LoRa just needs 4 dBm power to offer similar ranges like the ESP. With 4 dBm LoRa needs about 40mA instead if 120mA, again a good point for LoRa. c) Waiting for incoming data (receiving), here LoRa needs only about 12mA, the ESP needs way more for listening for incoming packets. In our RadioShuttle protocol software for LoRa (www.radioshuttle.de) we implemented an automatic transmission power adjustment which basically means most of the time we need only a fraction of the power. Regards from the Arduino Hannover LoRa Group, Helmut

[@AndreasSpiess]

Thanks for your feedback. I thought 5000 hours for LoRa was ok and I stopped :-) Frankly: This video was about ESP-Now, and LoRa was just used as a comparison for some aspects. Maybe I will once do another LoRa video and include your radioshuttle infrastructure.

[@gertux]

An other great video, as usual ! Did you check the impact of using encrypted transmission for the ESP-NOW ? LoRa is always encrypted. I wouldn't want to send clear text messages in a non-rural area.

[@AndreasSpiess]

No, I did not test it. I am not transferring any secret messages across such lines, so I had no need. I think, you just enter a key and then it encrypts (somehow)...

[@andreasjell734]

A very good video, thank you so much! I have a question. There are modules with an ESP32 and OLED and Antenna with LORA-Chip. For that modules, is it possible to use that antenna also for esp.now? Or only for LORA? Thanks

[@AndreasSpiess]

Lora is a different radio on a different frequency. The antenna is only fo this radio. Maybe you watch my video concerning these boards.

[@andreasjell734]

I did, and still I am watching... But I can't find out if there is a module which Esp.Now is working with a external antenna (and not with the chip antenna)...?

[@AndreasSpiess]

The ESP-07 module has aWiFi antenna connector

[@andreasjell734]

Yes that's right - but the ESP-07 is only an esp8266. I am looking for an ESP32 with antenna for EspNow

[@luisprates8223]

I have just discovered ESP-Now thanks to your video, so thank you! Although I do wonder if it's possible to use an analog input on master (a potentiometer in this case) to control a micro-servo on the slave. I have tried searching about this but to no real results.

[@AndreasSpiess]

This should be no problem. Maybe you divide the problem in parts?

[@luisprates8223]

@@AndreasSpiess thank you for the reply! Yes, I was thinking about reading the potentiometer value on master, converting into an absolute number between 1-255 and send to slave serial through esp-now. On slave, read the serial and use a "if" or "for" function to act on the serial value. I have yet to try this method but I do appreciate if you have any other method of going around this case or opinion about the validity of this :)

[@danieltrivino2935]

Hello Andres. Many thanks for sharing all this knowledge with all of us !. Thanking advantage of your knowledge and experience, would you guide me on how to implement the ESPnow protocol using micropython, please?

[@AndreasSpiess]

I have no experience with MicroPython :-(

[@danieltrivino2935]

@@AndreasSpiess Many thanks for your prompt answer...and sorry for misspelling your name. The auto correct some times is not that helpful

[@olivercopleston]

Hi Andreas, thanks for the vid. Any idea what the maximum theoretical speed of ESP-NOW is? For context: I'd like to stream video from one ESP-32 with a Camera to another which has an LCD display. I've figured that ESP-NOW is probably the best protocol to its lack of overhead.

[@AndreasSpiess]

It is always best testing it out because it depends on different factors. It should not be too complicated.

[@kevinroach9380]

Great videos! How about range? I need to get 200 - 300ft of point to point range. What is the best way to go?

[@AndreasSpiess]

If it is line of sight with no obstacles, WiFi might work. Otherwise LoRa is better. I would first try WiFi.

[@JerryEricsson]

Hmm I way typing a message and somehow did a shortcut and lost it, going back to an earlier video I was watching, well earlier. My question is, does this ESP-now work with all esp8266's or just the model 12 and above? I have quite a collection of these devices, and I can really see some advantages using this form of communications, especially in our RV which we spend our winters in, hiding in Arizona, while the frigid winters of the Dakota's make old folks like us regret ever settaling up there. The Mojave Desert is a wonderful place to spend the winter, it's 72 degrees here now, while back home they are enjoying indian summer today with the temps over 50 degrees however at night the Dakota's fall to zero F or lower, while here in the desert, it can get darn right cool at 55 degrees or so. Anyhow thanks, we seem to share an intrest in many of the same devices, so I look forward to your posts, knowing I will learn something new every week, and I have this strange belief that if you learn somthing new every day, you can fight off old age.. Works for me, most folks have no idea that I am 66, most put me at about 40 and if I take off my beard, even younger....

[@AndreasSpiess]

Sounds like a nice life! Here we prepare also for winter which can also go way below 0 (Celsius, of course). I traveled once from LA to New Orleans in 8 days, all backroads and still remember that it was a nice experience. Phoenix, Albuquerque, Los Alamos, Memphis, Clarksdale... Yes, ESP-Now should work on all ESPs. It is just a library.

[@stefa6901]

Thank you for this nice video! Helped me a lot. I created my own code for Esp Now and it works fine, but....using direct ESP2ESP communication made indoor range of a device very short distance. It could not connect to other ESP8266 which was just behind desk. I am using ESP01's for this project. Do you have any idea why is it so? Bad antenna on ESP01 maybe?

[@AndreasSpiess]

I did not do any range tests, so I do not know. But I would assume a similar range as in" normal" mode