Forget WiFi! This Wireless Method is WAY Better?

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Wireless communication is awesome! Right? Only problem is that there are many different methods and techniques which all use different frequencies and sometimes require extra hardware. But if you do not want to spend extra money on hardware, then the ESP microcontroller boards offer WiFi and Bluetooth. Those only come with a "short" range though. So in this video I will test ESP-NOW which is a wireless communication method that can be used with the ESP boards. It gets rid of many disadvantages while not needing extra hardware. So let's see what it can do and ultimately push it to the limit by building a crude Walkie-Talkie. Let's get started!

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0:00 A New Wireless Communication Method?
1:46 Intro
2:53 The Problem with WiFi & BT
4:22 Extra Hardware?
4:33 ESP-NOW Theory
5:10 First Test ESP-NOW
6:20 Range Test ESP-NOW
7:30 Comparison of all Wireless Methods
7:59 Walkie-Talkie Build with ESP-NOW
11:32 Verdict

[thenextproblem]

For those who don't know,
Any ESP can be switched to external antenna with small soldering skills
You can use espnow or espnow long range.
Espnow can be used simultaneously with wifi if you need a Gateway but not recommended

[pixieh.]

I'd like to give you a big thanks. Years ago I didn't even own a soldering iron. Thanks to your videos and inspiration-- I've tackled the basics all the way through to building my own ESC for an electric quad bike! Your videos are more than entertainment and/or tutorials-- they inspire and change peoples lives! Thank you Great Scott :). Thank you!

[CapnBry]

ESP-NOW really shines when it comes to low power designs, since it is connectionless. I converted a sensor over from wifi to espnow and it went from draining an 18650 in under a month to lasting over 6 months at which point I just ended the test. It should be noted that ESP-NOW does have a built in retry mechanism when used in unicast mode (which is when you tell it the destination MAC, i.e. not FF-FF-FF-FF-FF-FF). It will retry 11 total times at 11, 5, then 1Mbit, or even slower if "long range" is activated. This is important when you're going for a low latency connection like voice, that the total send time can be 0.1ms or 3-4ms for one packet!

[CaseyConnor]

As others have said: the esp32 can function in AP wireless mode, so you can connect to it without a router involved. Additionally many (most? all?) can function in STA and AP mode simultaneously, so they can connect to a wifi net at the same time something is connecting to them. I do this and it works great.

[RohrAtom]

Approx. 2 years ago, you was one of the Youtubers that motivated me to start tinkering with electonics myself. Meanwhile I finished a few successful projects. For example, I have built my own telemetry system for my RC helicopters using ESP-NOW communication. I also built a „customer detector“ with 2x ESP8266, a sonic distance measuring module, a few LEDs and ESP-NOW communication. Great videos, GreatScott!

[reinux]

I put together a zigbee network for my old workplace. Super low power, totally open protocol with encryption and mesh networking by default, works with a ton of off-the-shelf stuff (like IKEA lights and buttons), no single point of failure except for setting up the initial connection.
Industry routinely tries to kill it off beacuse it's really not that profitable and makes external data collection more difficult, but for users, it's really an ideal protocol.

[muhammadahsan]

Almost 3 years ago i have created a complete system based on ESP Now as a part of my FYP. It includes ESP now gateway, multiple sensors and actuator nodes, complete custom backend and mobile app for controlling everything. I made some modification to esp now based systems to increase it reliability as esp now is based on udp. Also everything is dynamic thanks to the esp now gateway i have designed. ESP now is very great low power protocol only if we use it properly.

[TD-er]

ESP-NOW is nice to play with, but it does have some quirks you need to know or else you will loose a lot of time debugging it.
For example, you better not use the full 250 byte payload length as this tends to work less reliable.
Better stay below 200-ish bytes per packet.
Also it seems like ESP-NOW does do some acknowledgements as the round-trip time increases when you extend the range. Like it does seem to lower the bandwidth and thus increase the possible range.

You need to set the MAC address as peer for sending to some other node, but not for receiving. So you can make it more dynamically with some coding effort. The maximum number of peers you can set depends on whether or not you use encryption.
And from experience, the broadcast feature tends to work even more unpredictable when adding more peers. So do not rely on broadcast packets.
Also there is some really odd stuff going on with the ESP radios when using any channel other than channel 1. So best to stay on channel 1 unless you have a very good reason to use another channel (e.g. when STA is connected to some other AP to try and use as a gateway)
You also need to set the channel when adding a peer, as the ESP-NOW code will remember the channel for a specific peer and if for some reason it assumed the peer was on another channel, you will see really poor performance as the radio needs to switch channels constantly.

You need to have a stable power supply when using an ESP-NOW node via its AP interface as this is constantly on. This is the fastest and most reliable mode for nodes that can be always powered as you will less likely miss a packet.
You can send packets via the STA interface, but only use this for nodes that really need to save the last bit of energy like some wake-up, fire and go to sleep again. In all other situations, use AP interface for ESP-NOW traffic. This also allows to properly set the channel.

If you keep all of these in mind, then ESP-NOW can be a really fun protocol to experiment with and the distance can get surprisingly long between nodes.
It also is quite fast as you mentioned. Like a few msec round-trip-time is to be expected when using the AP interface.

[g-whiz]

When I was in college (circa 1985), I built a one-way digital audio link (in this case using an LED and a photodiode) that employed a delta modulator (Analog Devices chip
?). The key benefit of the delta modulator is that the bit rate is low as data is only sent when the audio waveform is changing. I was quite impressed by the fidelity I achieved well below the Nyquist theorem.

[nathanielakkermans]

ESPnow is super cool, and there is also a long range mode. That in combination with the wifi on the lowest bitrate and some external antennes(but just simple 2dbi ones) i got 2, 5km of bi directional communication. But i have to say it was mounted on a rc plane

[PrajjalakChattopadhyay]

WiFi interference of ESP32 is a big problem. I faced it for the first time when I was designing a super stable and noise-free power supply for some specific project of our lab. The power supply output voltage was being controlled by the ESP. The WiFi interference was adding noise to the output voltage. Later we switched to STM32.

[sorinl]

Good video. But your comparison may generate some confusion. 433Mhz it's a frequency but Lora it's a modulation protocol. 433Mzh have been used for quite long time before Lora but here in EU Lora transmissions use same frequency plus 868Mhz. Living in Germany you must know that this country have a strong Meshcom community. For those who don't know Meshcom it's a Meshstatic like project that use only 433Mhz frequency.

[codebeat]

3:14 That isn't true, you can make a private network between modules without a router and when you do this with websockets it blazingly fast. Range can also be pretty good.

[JPs-qo]

So is this basically unbranded WiFi Direct™?

[saitamatechno]

best feature for espnow is "transfering data quickly" from my experience. And i did not know the lora module is in the low speed category as you showed in the video, thanks for it.

Comments are very informative! Thank you all, maker community!

[phoperdox_sore]

Just a side note that if you have multiple ESP32 boards communicating with each other via ESP-NOW especially for fast data transfer applications (like RC Car), there might be noticeable lags in the data transfer (but no data loss I think) until you leave only one ESP32 pair communicating. This is, from what I have experienced, due to too much activity in the ESP-NOW channel you set for each ESP32 pair.

There are a few lines of code mentioned in the Espressif docs that allow you to change the channel, just like WiFi, but it was not obvious (at least for me) :(

[fbach]

Don’t you need an antialiasing filter between the mic amp and the ADC ? I think it would be wise to filter out everything above 3 or 4 KHz (depending on the sampling frequency).

[Tony-rlfr]

I love the WW1 sound of the esp transmission.

[seank]

THANK YOU! This video is exactly what I have been trying to research for my project. Alternatives to all the other wireless standards. I use ESPs from adafruit and never knew about ESP-Now. Your channel has informed me about soooo much! Thank you!

[name_is_taha]

I have found out that if you use the ESP-32 Dev Modules that has external antenna connector you can greatly improve the range.