Are there any long range microphones for Jetson Nano Dev Kit (4GB)? (At least 20-30 meters range ideally)

[nto]

Hello! I’m building a robot that should be able to hear sounds from quite afar (from at least 20-30 meters away) and I don’t know which microphone to get for my Jetson Nano Dev Kit to make it work… (the mic will sit on top of the wheeled robot) I know there are USB microphones such as the Blue Yeti, but they’re made for REALLY close range as far as I know…

I know there are other options like Shutgun microphones but those don’t usually come with USB and only capture sound from a specific direction (not good, 360 needed, or at least something like 180), and then Parabolic Microphones which I don’t know how to interface with the Jetson, if there is any way to do that.

Do you guys know any microphones that may work for my application? Or where I can find or select one?

[linuxdev]

I can’t help with a specific suggestion, but it sounds like you want a more directional microphone…lots of sensitivity in a particular direction. That’s a supercardioid design. The main problem there is that you will then need to aim the microphone. If you don’t have a way to aim, then it might not do what you want.

[nto]

Thank you for the suggestion! That’s the problem, it must be omnidirectional, so that it picks sound from every angle…

I discovered that quality USB microphones can pick up sound up to about 10 meters if you increase the gain. Obviously this introduces the problem of noise that’s ALSO being picked up by the mic, but since the budget for the mic is about 200-250 EUR MAX, I think it would make sense just to bite the bullet and go with something like a Blue Yeti, which I saw people use with Linux quite a lot without issues.

With a good enough filtering and a good code I think the Jetson will be able to pick up human sounds from decently afar. Not the 20meters minimum that it should’ve been, but fair enough.

If I find some other microphone however, will it be compatible with the Jetson Nano’s Linux? As long as it’s USB, or XLR with a dongle it should work, right?

[linuxdev]

Signal to noise ratio is always a problem in anything analog. There are ultra low noise amplifiers for that purpose. This of course does not help unless the noise source is EM (actual background noise will be amplified just as much). What is the source of noise you are having interference from when amplifying your current microphone? I’m wondering if it is electrical or physical in nature, e.g., a power line hum.

[nto]

Ultra low noise amplifiers? I haven’t yet purchased a microphone so I’m not sure if the noise will be electrical or physical. I think in order to tell for sure it would make sense to test it, but I’m yet to pick a mic.

Will the low noise amplifiers work with a Jetson Nano 4GB? If yes, are they really required to amplify the actual surroundings sounds or that can be done within software? Could you give me a link to a vendor for reference?

[linuxdev]

I can’t really answer that. I can give you things to look at though.

Amplifiers are of course for the analog end. Some microphones are i2s, e.g., which are purely digital, which is typical of what you’d see in a cell phone (they are surface mount, and very tiny). There’s be no way to put an analog amplifier there.

Other microphones are purely analog, and do not use USB, while others are analog, but do use USB. In the case of a non-USB version you could just plug that into an amplifier, and then the amplified signal into the Jetson (you’d need something to plug it in to…that might be your main problem for anything not USB, although there is an i2s function). My guess is that due to the connector you are going to pick USB.

Some variations:

• You could get an analog USB microphone with the intent of actually cutting in to the wiring and installing a small amplifier. Not something to just purchase, so you might have some failed results (and costs) along the way.
• You could get a digital USB microphone and just use that.
• You could get a non-USB analog microphone, put it through an amplifier, and the amplifier itself could convert to USB (technically, it could convert to i2s, but I don’t think you’ll find that combination; if you did find that, then it might be the best choice).

Note that anything analog will tend to pick up EM noise on any cable which is not properly shielded. Digital wiring won’t have that problem, but digital won’t have the ability to add analog amplification.

I don’t know what your budget is, but I’m going to suggest you consider a cheap experiment before committing to some final choice (unless you find something that is built for the purpose): Get an inexpensive analog directional microphone. See how it does. Consider cutting in to this if you are comfortable soldering and working with electronics and splicing in a small low noise amplifier (lots of those available if you are flexible and have some experience soldering) if and only if performance is not sufficient (you’d splice in to the analog line that leads to the USB).

There so many individual ultra low noise op amps available for cheap it is hard to list any. You’d have to design that yourself, but if you have any engineering experience, it is trivial (making the circuit board is the hard part, but there are ways around that). Pre-built ultra low noise amplifiers which are small are out there, but less common.

You might want to start with something simple like a Google search.

Someone else may have a specific microphone suggestion, but anything USB or i2s should work. The only question is whether it is useful for your purposes. Incidentally, if it is USB and works on a desktop PC, then it should also work on a Jetson. Do you have a test microphone already which plugs into a PC? Try that.

See also:
https://www.amazon.com/directional-microphone/s?k=directional+microphone