Haha, but I congratulate your focus on quality !!🔥

You asked for Fiber, but you deserve 64k ISDN speed for reupping the video 😇

not gonna lie, I didn't even noticed it hahaha

Didn't bother me at all... one might even say it was zero hurts for me.

never, infact youtube should double the view count, i blame them

???

I also can't wait to see that :-D

IKR, though the math/physics principles have been pretty known for quite a while as well as some actual existing HW/SW implementations that aren't totally proprietary anyway. But yea its amazing just how far we've come over the decades & how readily available everything required for such a project is, even to a DIY engineer.

Using a lock-in amplifier perhaps?

dude the math is pretty basic bachelor in engineering-level... Programming the microcontroller to work at those speeds is where the complexity of this project comes

​@@bitlunislabДальше увеличим количество приёмников и получим ультразвуковой 3D сканер для дополненной реальности?) Будем без включённого света видеть окружение😏😏😏

This is even a cheap version :-D I bet the RP2040 could do all the stuff in PIO

@@bitlunislab Could you use this in maybe a multi level set of arrays to make one of those fish finders?

So basically the rl version of the little arrow you see in video games showing you were the shots were fired from, pretty cool

@@xxportalxx. dam, i never thought that such a device could exist. But it makes sense now, to have a phased array microphone system would work very similar.

I did a university project where I determined the angle of a body respective of a sound source by using digital cross-correlation techniques. Made an A! Now, we can see this kind of math being used in sniper shot detection and ranging.

​​@@DrumToTheBassWoop You get more bang for the buck with beamforming phase-shift arrays. This beamforming technology could augment LiDAR for 3D mapping.

i graduated from the Army signal corps in 87, everything was analog then, n accuracy was really based on the operators ability to interpret the signal n of course u always had unwanted frequencies n freq drift as equip got hot gumming things up, but i got very good at that n I'm amazed at how small n more accurate the new tech is and this just reminds me most of the old tech but on steroids.

What's Prime Fractions? I googled, but only found prime factorisation

Placing at primes is a good idea. It make a significant difference in performance?

@@LydellAaron so you have a spacing distance between sensors. Then you say do a 7/5 of that distance and a 14/11 of the distance. The waves that line up with the consistent distance now are not lined up with these odd spacing. it helps separate out things.

@@LaserFur I haven't checked your math, but I do see what you mean in spacing the sensors. Question: Could you tune each ultrasonic, to emit a pure prime frequency, keeping the distances the same?

its only 8 pins which are adjacent to the IC corner. The of all the BGA boards the last ADC didn't work. I used a different type for the tests shown here (code still works the same). I never really found the issue. The solder mask is a bit wide open on one of the pads. The pin pitch also exceeds the specks of the manufacturers fast shipped PCBs. I tried the BGAs because they were the cheapest and support 12bit at 3MSa max. Still would use sot for product because of the reliability.

@@bitlunislab Well, even attempting it was brave! Glad you got a work-around for that last ADC and was able to move the project forward... much respect for you!

caught you there

That's the diameter of the case. The transducer is inside and smaller.

You could emit a chirp from 0 to 10 kHz and capture this with a slow Adc (20kHz sample rate) of a microcontroller. Then you could emit a chirp from 10kHz until 20kHz. In this way you can cover the full spectrum where your transmitter and receiver are sensitive. One requirement is that you should have no aliasing filter in your receiver path Also the sample and hold circuitry should sample in a sufficiently short time window and the sampling times between transmitter and receiver shall be triggered with low jitter.

based fellow communist electronics enthusiast

Looks like I had a bad idea if the goal is direction finding. MICROPHONE ARRAY PROCESSING OF PULSE-DENSITY MODULATED BITSTREAMS Conference Paper · January 2018 Ipenza, Sammy Carbajal ; Masiero, Bruno S It still feels to me like there should be a way to avoid the FFT(s) and do some sort of fuzzy statistical comparison of the streams to get time of flight and phase. I need to re-watch this video to see how bitluni did it. I don't remember FFTs here. Interestingly PDM seems to be good input for spiking neural networks--maybe a completely different AI based approach would work.

PDM to PCM conversion is basically done using low pass CIC filter (with decimation), which reduces data rate by some factor (/64). This is followed by a cross-correlation of signals from different microphones. The low pass filter doesn't do much but reduces the data rate and size of the array in memory. So, it should be possible to skip that step, but at the expense of bigger RAM. Personally, i would use 8 of ESP32 boards, one per the PDM microphone, and process acquired data using RPi.

Cost in parts, very little. Cost in time and knowledge, lots and lots... Not everything can be boiled down to the $ easilly

This is possible but the drawback is called a blocking distance. The transmitter rings for a period of time after excitation had ceased. This time is distance the transmitter won't be able to see. It would be blind close up for the transmitter element.

good point... might hit exactly the 0 transition and get nothing

so now after a night of pondering, it seems i need to take the audio data stream and step through it, hopefully only on areas marked by fft as having a carrier of known amplitude. stepped by sliding a window of one ping size (thinking 10 bits) over it, adding/subtracting a sine wave of the target frequency to see if it increases or decreases the total audio noise. then repeat with the calculated sine wave starting at different positions on its cycle and at different amplitudes. best matches are identified by finding where they cancel out most. from here, fine tune the phase and amplitude by tiny stepping until it's perfect, and that is the start time to flag. also at this point try stretching or compressing the sine to find any doppler shift. by knowing the exact time a ping is received on all 3 sensors with their positions tracked by accelerometer and gyroscope, the source can be triangulated directly. at this point, the three (phase aligned and stretched) audio streams can be stacked like a rake receiver for better signal clarity, transform as needed and feed it into the morse code reader or uart to receive the keyed data contents sent from other boats. so that's my best guess on how to go about this. anyone have any ideas on easier ways to do any of this? fml. at least from here ai can take over and do voice like recognition on the serial blips because it has accurate feedback to train it, and get better reception in noisy environments. but i mainly want automatic course correction on my rc speedboat to avoid collisions with swimmers or pier posts and that needs 3d sonar mapping so here i am.