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Phased Array Microphone (2023)

benwang.dev

1–10 of 191 posts

Re: Phased Array Microphone (2023)

#2
Nice. It would be cool if this project could cleanly separate sources based on location.

That would be a bit like a lightfield camera, where you can edit the focusing parameters after the image has already been taken, but now with sound.

https://en.wikipedia.org/wiki/Light_field_camera

Re: Phased Array Microphone (2023)

#3
I once did a project to do multilateration of bats (the flying mammal) using an array of 4 microphones arranged in a big Y shape on the ground. Using the time difference of arrival at the four microphones, we could find the positions of each bat that flew over the array, as well as identify the species. It was used for an environmental study to determine the impact of installing wind turbines. Fun times.

Re: Phased Array Microphone (2023)

#4
I'm a bit surprised by those long "arm" PCBs. They are already doing calibration to account for some relatively large offsets: why not place each sensor on its own PCB, mount them to some carrier structure, and let calibration deal with the rest?

Re: Phased Array Microphone (2023)

#8
This is more or less the same principle of how Amazon Echo devices work, but on steroids.

Very neat. I would be surprised if you aren’t seeing some diminished marginal returns from all those extra mics, but I guess you’re trying to capture azimuth deltas that Echo devices don’t really care about.

Re: Phased Array Microphone (2023)

#9
post #6

What is the most practical application for this technology? Could you use it to pinpoint sounds coming from a car like a squeak?

A similar technique is very popular in industrial automation to spot leaks in compressed air pipes and their connections from far away. These leaks are extremely loud in the ultrasonic range. It's overlayed with a camera picture.

That's ultra expensive gear.

Re: Phased Array Microphone (2023)

#10
If somebody wants to play around with Zynq 7010's - have a look at the EBAZ4205 board. They can be bought from Aliexpress (20-30€). These are former Bitcoin Mining controllers.

Some people reverse engineered the entire thing. It can be found in GitHub. And there's an adapter plate available for getting to the GPIOs.

For a less complex entry there are also Chinese FPGAs ("Sipeed" boards which use a GoWin FPGA. They are quite capable and the IDE is free.

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