This ESP32 Antenna Array Can See WiFi

As a research assistant at the Institute of Telecommunications at the University of Stuttgart, I work on multi-antenna systems like (distributed) massive MIMO, with a focus on wireless channel measurement platforms and algorithms for processing channel measurements (classical and deep learning-based).

One day, my (incredibly talented) colleague Marc Gauger suggested to use ultra low-cost ESP32 chips instead of software defined radios for channel measurements. I was highly sceptical at first, but when he showed me a minimalistic prototype he had soldered together, I was intrigued by the idea of being able to demonstrate my algorithms in real time using WiFi signals. In a series of Bachelor's / Research theses, my excellent students Tim Schneider, David Engelbrecht and David Kellner helped me develop the ESP32 antenna array "ESPARGOS".

My research on (distributed) massive MIMO, Channel Charting and other algorithms for multi-antenna systems is funded by the German Federal Ministry of Education and Research (BMBF) within the project Open6GHub (grant no. 16KISK019).
I also want to express my gratitude towards ARENA2036, who hosted our measurement campaign for Channel Charting, and to my colleague and Channel Charting expert Phillip Stephan, with whom I co-authored several papers on Channel Charting and who assisted me with the creation of this video.

[Jeija]

Wow, thanks so much for the positive feedback 😀! I knew this video might get some views, but I honestly didn’t expect _this_ many people to reach out asking how to get their hands on one of these boards.


For those of you who sent me an email, please bear with me 🙏, I will reply to your messages over the next couple of days.

[fgbhrl]

At first when I saw the array of EDP32s, I was like "nah, this is some silly half-baked idea". I'm still trying to remove my jaw from the floor. Bravo, sir.

[TheAMFT]

Love this, One of those moments where I ran to tell my wife about it before I realized she doesn't care lol

[ProgrammingWithJulius]

My dude woke up after 7 years and decided it was time for a banger video

Also, German accent haunts us both

It never ceases to amaze me when I find amazing projects like this in the endless ocean of worthless influencer bs on YT.

[admiralgma]

I have a Masters degree in electrical engineering with my graduation thesis done on topic of IEEE 802.11 THIS VIDEO IS BY FAR THE BEST CONTENT ON WIFI THAT I HAVE EVER SEEN IN MY 26 YEARS LONG CAREER CONGRATULATIONS AND LONG STANDING APPLAUSE x 1000

[MegaCadr]

I like how he just casually drops the AI doing magic thing towards the end, as if everything before that wasn’t crazy enough.

[gmag]

Getting phase coherence with something as cheap as esp32 is mind blowing. My respect!

Something similar with professional hardware would cost hundreds thousands euros/dollars

[mihailsichitiu]

Dude, that's a PhD worth of work presented in 10 minutes of beautiful presentation and explanation! Congrats - I rarely see a video so well done in so many dimensions: eye candy, technical explanation, supporting graphics, etc.!

[googleyoutubechannel]

You are kidding me? Timed signal paths for hz sync? Channel charting? Please tell me you're a PhD in RF black magic... this is the most sophisticated project I've seen on YT... wow

[jeroenconinx]

As an electronics engineer and having some experience with multiple parallel FPGA test platforms, when I saw the idea to put 8 ESP's on a board, I was like, "nah, timing's not gonna work". Super impressed with you getting frequency-synchronicity and phase coherence down on the ESP's. Bravo! One of the most impressive things I've seen on youtube.

[gregdand]

This is absolutely incredible. My brother and I were talking about a similar concept but for ham radio VHF, and I guess it only just occurred to me that the "eyes" you'd have to build would be absurdly enormous to achieve the fidelity you did here.

This project is amazing.

[scottnee]

After 20 years, I finally signed in, subscribed, and liked a video. I have been watching YouTube since 2005 but, I have always refused to sign in. RF, Electronics, and Programming are my wheelhouse. I am the retired Chief Engineer of Packer Radio, EXTRA Class radio operator with a degree in Electronics. I have been programming since 1983 and I adore ESP32. I couldn't even count how many ESP32's I have.... Yet, you sir, have impressed me. Please keep up the amazing work!!! I will be sharing this with EVERYONE!

[alexscarbro]

Assuming the PLL is an Integer type, the phase delays are not “random”, but rather they are discrete and determined by the value in the N counters at the time of power up as they are not synchronously reset to the same value.

[thriler]

Whenever I find video on YouTube, where i don't understand almost anything that was said, with so many views it gives me hope for this world. So rare. People like you are gems of this world sir.

[DXCommanderHQ]

The reason this video has blown up for you is because it's really good work, great experiement and also has a "how to" element. First class. Subscribed.

[martinbrennan]

Outstanding work. I was impressed enough that you could do the phased array stuff but adding the ML on top is a tour de force.

[drino]

this is a rare embedded programming project in youtube. I am feeling lucky because this video appear in my recommendation

[OH-cjif]

I did a lot of work with a project called Celldar in the 90s. The idea was to analyse the reflected RF from people and vehicles and produce a map. The tech was quite slow then, but it used the early cellphone frequencies.
All you could see was blobs moving, different sizes, but nothing to differentiate people.
It was going to be used as a passive radar system for planes, but people forgot that cell towers use a downward tilt.
It was abandoned after a few years and a lot of government funding.
This is far more exciting.

[rfguys]

This is some serious research project. The idea of beam forming using phase array have been around for many years. But I see two new potential applications here: 1. wireless signal strength mapping overlay with real time video. A drone will be very much exposed as a 2.4G hot spot even at night. It can be used in the battle field right away. The wireless carrier will be interested to see their base station coverage (of course this will be more complicated as there are a lot more different frequencies being used). 2. Indoor 3D structure mapping using a single transmitter through channel charting. Something like in the movie Alien: Prometheus the explorers 3D mapped the tunnel using drones.