DIY Sonar Scanner Ep. 2 (STEM, RMT tricks) 

re-upload because I misspelled Hertz🤦🏻‍♂...in an educational video about physics. I deserved it if you un-bell me

Is part 3 coming anytime soon? I can’t wait to see how this project developed!

Geeeeeeezzzz. This is a mind-bogglingly advanced maker project. I can't believe all this is possible without a PhD in ultrasonic and signal theory, and a big lab. Let along possible with an ESP and off-the-shelf hardware! Great work! I can't wait to see how you amplify the output signal without introducing "noise" into the rest of your system.

Always amazed at how far you can push some of these microcontrollers!

As a former USN sonarman in the early days of towed arrays, this brings back fond memories. I had learned theory in cylindrical active arrays, but tight passive beamforming and frequency resolution well to the right of the decimal point - even for ridiculously low freqs - was a whole new ballgame. The math still makes my head hurt though. 😏

I was working on the same kind of plan 14 years ago. one thing I noticed is that it's better to space the receiver array with prime fractions in between each detector. so the detectors are not spaced evenly. This prevents a picket fence type sensing issue. Also there are wider bandwidth ultrasonic detectors, but they operate at higher frequencies and thus increase the difficulty of the electronics.

Great physics, presentation is clear and concise, but also very appealing. Sound background in simulation part of the video is extraordinary 🤗 for the electronics side of the project: 🤯

Fantastic! WOW! And you managed to get a PCB with BGA's on them... impressive! Thanks for sharing this... I can't wait to see how you process the data and interpret it.

The US military had the 5 omni-directional microphone version, installed on some humvees that pinpointed the afghan snipers, when they fired. Machine-gun galore after that. Mountain echos and all. Now there's a small version called the "Sniper Detecting Microphone", a part of their TCAPS (Tactical Communications and Protective Systems). Smaller than a pack of cigarettes, the solider sticks to the back of his helmet. I like yours better because it's based on an ESP32.

The animations in this are excellent. Well done!

You can use the DMA in the STM's as well. It is very capable at reading data from GPIO pins triggered by a lot of alternative sources.

Braver man than I with those BGAs! This is a really cool series. Great to see a phased array application I could actually build one day. Wonderful exercise of the theory too. 👍

I love the thumbnail "... this is what AI thinks...." ... and the ambient music + sonar sound effects soundtrack.... nice!

Fascinating project! I am very curious about the next video ☺ (And, I also think MEMS microphones would be an interesting idea 😁)

THIS IS SO AMAZING! Thank you for documenting all of these cool projects for us.

I will wait for the next part and I love the ESP32 but my surrounding makers hate it, now I can share this video and point out one more time how awesome this controller is.

The STM series also features DMA, which can really improve your GPIO speed dramatically. My mind goes straight for an FPGA with this use case, and I give you massive credit for how much you've been able to get a lowly ESP32 to do!!! Impressive!🤘🤓

This series is awesome!

Ok....the next video bitluni does a ultrasound image of a baby using esp32

Absolutely loving this project!

Wow, this is awesome work. Coincidentally I came across this while planning to do my own project to attempt the same thing. This is great motivation!

I love this. Especially the multiple channels at once sampling.

So much yes! Great project and amaze editing and presentation! Love it

Great project laid out in great yet simple detail

Loving this series, man!

Nooooo. Where is ep. 3!???? This is really fun to watch!

That's why submarine radars use a non-repeating melody to scan the environment. That way you can distinguish between the different echos.

Just when I thought this project couldn't get more genius, it got more genius.

I recently used four analog MUXs with the select lines driven by shift registers to read 64 analog hall effect sensors in "real(ish)" time.

Thank you for such precious documentation.

You could just bandpass the transducers in the rx array and measure the time delay at baseband. No need to actually measure the waveform directly. Great video, look forward to seeing more on the subject.

Amazing work. Loved it

Great idea and great video! Looking forward to see the next videos.

Excellent video from any point of view.

I would highly recommend programming the ESP-32 using the PlatformIO extension in VScode. Not only is VScode just a generally better IDE, but the default ESP-32 framework (which virtually perfectly mimics the default Arduino framework) is actually built on FreeRTOS, which can leverage both cores of the ESP-32 and allow true concurrent multitasking. This is achieved simply by making calls to the FreeRTOS API with no modifications or extra library imports needed, which is freaking sweet for a 6$ microcontroller.

a different world. It's the sa laws, but different application. Without your videos, I'm not sure I would be at the level I'm at. I'm not a pro

Hi, I was wondering if you are going to continue this series on the phased array sonar?

Nice Project!!consider looking at phase modulated pulses to get higher resolution without sacrificing power out on you pulse!

TNice tutorials was an amazing tutorial. You are a great teacher

Nice video! Waiting for more!

Nice content. I think, everyone who works with prototypes hates jumper wires except probably newbies.

If you add additional transmitters offset by the size of the 8 receiver array, then you will have a MIMO-array with twice the angular resolution. You would simply record one frame with one transmitter active, then another with the other transmitter active.

Very cool project sir impressive.

Absolutely awesome.

Awesome project!!! Best regards from Ukraine, Odesa!:)

Dear Bitluni; The sport of soaring cross country involves the glider flying to areas of convective lift to gain or maintain altitude to fly distances. This means it would be nice for the pilot to have some kind of thermal scanner to observe areas of lift in the vicinity of the aircraft. Now the pilot has to guess where these areas are by visual clues and then flying ahead to confirm the lift by instruments of vertical speed. The concept of a "lift scanner" has been a dream of soaring pilots for generations. I am wondering if phased array transmitters and detectors might be a possible solution. I have read that microwave radiation might be used here. You do great stuff!

Nice echo visualizations, it helps wrap one’s head around the relativity.

So cool :O Cant wait for the next one

what a BEAUTIFUL video!!

Everything works at its best!!

Love these videos!

This project is SO COOL! I can't wait until you create a fully functional Alien motion detector. 😅

Wow! So cool!

holy crap, this is amazing!

Thanks for this video

This is awesome!

Incredibly informative. As soone with no background in soft other than so Nice tutorialgh school band, I completely understand everytNice tutorialng

Nice job !!!

I used aisler tooo ! There awesome !!!

Nifty AF !

This is awesome

Nice video, thanks :)

BRILLIANT!!!!

One more epic, do more uploads plz 👍🤟

like your videos sir... waiting for part 3... love from pakistan

Nice one !...cheers.

super cool

amazing to see people like you

Those PCBs look like they could be very useful in some DIY scientific endeavours.

very cool

2:55 sounds like ElectroBoom 😊

This is a next level project :) I wonder why don't you used the native ESP-IDF it is more powerful than ARDUINO IDE

It's a baby 👶 congratulations 🎊

I just discovered this channel, is the part 3 coming ? That's really interesting even if I don't understand everything :)

Subbed!

Wow! Thus is a great project! And when you are finished you can scare moths with targeted beams.😈😆 I guess chatting with bats will take a little longer? 😄

I had a look at Aisler... not as cheap as the PRC people, but, having actually run a business doing electronic design and development, their pricing structure makes sense, seems quite transparent. It might be a plan, if you feel ok with it, to give the price for a board that you are building? For me, I guess it would be interesting for a bare board price, on a board that's reasonable to assemble in a hobbyist lab, and a price for a fully built board, including their sourcing and mounting of components. The setup fees stack up a bit, but compared to damage to boards or components, trying to do it "at home" 😁

This is fascinating! Just after I watched both of these videos, I stumbled across a 2003 paper that says the following without including a citation for it's claim. "Since the wavelength of 40 kHz ultrasound is only 8.6 mm, a receiver with dimension larger than the wavelength is not recommended for wavelength measurements." DOI 10.1088/0031-9120/38/5/310 In the first video, I think you showed us that the smaller transducer has a 9.6 mm diameter. If the paper is correct, then would smaller receivers give you more precision?

super impressive! Your PCBs look like they have a lot of cross talk between the different digital signals which is probably limiting your sampling rate, whats your board stack up and how are the board interconnects carrying ground is what id look at first.

I would still like to get your help on designing my "flashlight for the blind" based on a laser range finder. But if you were able to map surfaces with your sonar, maybe that would work too. I found sonar to be too slow for distance measurements. But the tactile feedback for a flashlight for the blind would most likely use tiny electrical pulses on the forearm. Or possibly on the hand and fingers if it were implemented in a glove. Imagine feeling your way down the street with 30 foot long fingers. i'm quite certain that something small and functional could be designed to work on a rechargeable 9 V battery. Or maybe more batteries. Something that would fit in one's pocket certainly. This would be a tremendous benefit to many people. The cane is a very reliable mechanism, but it could certainly expand one's horizon to be able to feel doorways and windows and street signs coming up. To be able to sense people 20 feet away walking toward you. Perhaps

Really cool project. I was wondering if it's possible to realize this with Ultrasonic signals instead of microwaves. eagerly waiting for the next video.

Stm32f3 series internal ADCs have more than enough speed for you :) f303 has 4 ADCs at 5MSPS each, for example. Straight to memory with DMA.

Cool

I think that RPi Pico, with its programmable and full system clock speed PIO state machines, is far better choice for high-speed ADCs than ESP32. Also take into consideration its great overclockability. I think it will be possible to build even multi-megahertz ADC circuits with it.

Great guy! Is it really amazing to see your experiment. Is it possible to make a medical grade ultrasound scanner?

I wonder if you could use a 4D lidar camera and a speaker and microphone to train a neural network to map the received audio signal to the scan. You could also use something like the Google cars scanner (idk if they use synthetic aperture lidar but that may make things cheaper) to also regress the audio signal. One upside is it can learn ambient echo patterns too!

Excellent. I'm a little creeped out because I just started work on this same basic idea this morning and out of the blue RU-vid suggested this video in the early afternoon. That wouldn't be remarkable except that I haven't googled yet aside from looking for a schematic for the HC-SR04 board to see if there is anything worth salvaging. I considering trying to figure out if I could use Knowles digital ultrasonic microphones. IIRC the ESP32 maxes out at 2 PDM inputs and that is with interleaving left and right channels that probably doesn't help much. But I do have an old FPGA laying around which is grunty enough to handle converting several PDM streams to PCM. But I wonder if there might be a good algorithm for getting phase and echo times out of the PDM signal? In other words, each microphone has a 1-bit SAR ADC built in. Would it be possible to use the 1-bit stream from each microphone directly instead of first converting to PCM. Each mic's bit stream flows at around 3-5 MHz in ultrasonic mode and it takes somewhat serious number crunching to get that to 16-bit PCM so it might be nice to skip that and go directly to finding echo delay and phase. That might allow the final version to use an inexpensive FPGA dev board. Anyway just an incomplete thought which maybe you know something about.

Nyquist says you must sample at GREATER THAN twice the frequency. Sampling at exactly twice takes an infinite number of samples and produces an alternating output. Sample at 4 or 18 timeds the frequnecy or as much as possible. If you know the amplitude you can find phase at 2f, but you don't know amplitude.

Wow, amazing project! I'm looking forward to trying it myself. Is there any link to order the pcb?

Those animations are amazing! How did you do them ?

You could try to transmit from the same elements and then switch to reception, as radars do, instead of one transmitting element centralized (which can add a phase shift along the array)

This series is absolutely amazing. How much do you think it will cost you to make these in the end?

Great work and I was following up with your project. My question is how do I calculate the required power to make this scanner works in different media than air such as air?

Great video...Thank you... I was wondering what the app you used for the sound simulation was?

Well you got the tech for my project that I'd like to do, a phased array microphone. Start with an audio frequency microphone 2D phased array to resolve a 3D volume. Each cell in the volume would be the sum of phased inputs from each microphone processed to show a live FFT to give a colour for spectral content and transparency for amplitude. This would be way better than the sound camera I saw over at @SteveMould with the acoustic camera as it ought to show all sound all the time.

Amazing! Would it be plausible to use lower frequencies of sound that can go through various objects and “see” through walls?

Fascinating. I don't quite understand your argument that you need parallel readout of the sensors. If the scene is static or nothing is moving very fast then the receivers could be read out sequentially. I would like to see the transmitter moved on a linear stage. Then you could create a synthetic aperture.

Congratz you made an ultrasound machine😂😂

I wonder if the rpi nano's programmable io peripheral would help or hinder here. Seems like itd be an interesting test at any rate.

Attention! You are approaching ambisonics territory 🙂