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TinySA – small spectrum analyzer and signal generator (tinysa.org)
192 points by transpute on Jan 26, 2024 | hide | past | favorite | 64 comments


These are being used by the Ukrainian army for detecting incoming russian drones.

https://www.linkedin.com/posts/eyesonukraine_drone-detector-...

The firmware source is on GitHub at https://github.com/erikkaashoek/tinySA.


If they know frequency of drones (i.e. Lancet in this case) can they create something like a HARM drone, which will guide itself on source of the signal to intercept the drone itself?


A drone dangling balls of yarn...


Are they using any peculiar feature of the TinySA? From the photo it seems they're doing normal spectrum monitoring, but for that purpose a SDR dongle would work as well, For rexample the one by rtl-sdr.com. Beside being much cheaper, it can be interfaced easily with also cheap *Pi-like single board computers and operated remotely to cover wide areas. But again I have no idea if the TinySA offers any advantage over a SDR receiver in that context.


The other reply to you is buried for some reason but as they said, a hand-held battery powered unit is more convenient than something that requires a computer.


Unfortunately, the bandwidth on the RTL-based dongles is quite limited. This means that you'll only see some kHz of spectrum around your LO frequency.


1Mhz on either side but your point stands.


Portability and effectiveness. Sure, for you a dongle is great. But not if you're in the trenches covered in mud and you have to dig it out of a pocket somewhere ..


It surprises me that military drones aren't using spread spectrum to make this harder.


A lot of the drones are off the shelf drones. This war is revolutionary from a tech POV, a lot of the solutions are cobbled together -> see "cope cages"


Yeah or satellite uplinks that only transmit straight up, much harder to detect and to jam.


Is that a real thing, or a star trek reference?


A real thing: https://en.wikipedia.org/wiki/Spread_spectrum

Fun fact, the famous actress Hedy Lamarr actually was instrumental in inventing it!


You can tell GP is under 40 or they'd probably remember cordless phones "Now with 900mhz spread-spectrum technology"


Definitely a real thing. Also, during WWII actress Hedy Lamarr developed a system for spread spectrum torpedo guidance to prevent jamming, but the general idea predates that.


Yes, it’s a thing. A long time ago, my work involved a frequency hopping, spread spectrum radio link. Can’t say much about it but I’m sure that the technology has improved since then.


Hopefully its not pedantic or unwelcome of me to make the distinction between spread-spectrum and frequency hopping.

With frequency hopping only one frequency is used at once, and they're selected according to a sequence that matches a shared PRNG. As I understand it, that's what Bluetooth and some Wifi links do. They switch between discrete bands very fast.

Spread spectrum is a little different. During modulation, as with FM a series of side bands spread out. Normally we would limit these as they're considered "interference". But with the right modulator you can spread (and indeed encrypt at the RF link level) information into some bands but not others. Although all sidebands are present, to an observer who can't tell which ones carry the data at any moment, it makes no sense to even try demodulating the signal.

Neither solutions are much use if you need to communicate back because triangulation alone is enough to find you.

Curious if this tallys with your understanding, its over a decade since I had anything to so with this sort of thing. The best summary I recall was in Ross Anderson's "Security Engineering" book (first ed.)


>Hopefully its not pedantic or unwelcome of me to make the distinction between spread-spectrum and frequency hopping

Spread spectrum refers to any technique where a narrowband signal is deliberately spread to occupy a larger bandwidth.

Frequency-hopping is an example of a spread spectrum technique; they're not different things. Direct-sequence spread spectrum (which is what I think you're describing) is also a spread spectrum technique.

There are also other techniques; the most popular one is probably the chirp spread spectrum as used in LoRA.


Thanks for the clarification NW


No, it’s fine by me. I believe that it was thought that the combination of frequency hopping and spread spectrum would make it difficult to monitor and jam ( other than very wide band jamming). My application was rapidly moving so triangulation would be difficult.

If I understand the capabilities of modern Software Defined Radio systems, then they can monitor many different frequencies at the same time which might defeat those old systems. It’s been a long time since I read up on the current ideas and capabilities.


> If I understand the capabilities of modern Software Defined Radio systems, then they can monitor many different frequencies at the same time

Haven't been keeping up with it as much as I should, but that's very interesting.


Isn't good old cdma a spreadspectrum technique, used for cell phones back in the day from quallcomm?


Yes, one of the four basic types. CDMA is the Direct Sequence Spread Spectrum variant.

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


Spread Spectrum is very real, it was used in 802.11b.


Yes and Bluetooth.

In those cases it's not used to make detection harder though but to be more resilient against interference.


This might have to be my next DIY project...


Make sure to heed the maximum input and use an attenuator!

These are very cool and fun, but I found myself using my NanoVNA a lot more than my TinySA

https://nanovna.com/


Both are super handy and super cheap (relative to conventional SAs and NAs). Handy for the personal shop of any EE.


I use a nanoVNA for analyzing antennas. Cool tip is you can tether it to an Android device and get a bigger, nicer touch screen.


That's cool - didn't know that about Android.

Another cool tip is to use NanoVNASaver (https://nanovna.com/?page_id=90)


For sure - if you can afford them, get both. I was just surprised because I expected to use the SA a lot more when I got it. But I am mostly either testing filters are designing antennas, and the NA is the way to go.


I have only NanoVNAs, up to the 6 GHz one ( https://nanorfe.com/vna6000.html ). But the TinySA at the frequencies of interest seems about the same?

I guess what I'm asking: What features of the NanoVNA make it the "way to go"?

FOR ME: It's the PC SW that allows a big-screen, which converts the fundamental "R+jX" measurement into many different views. https://nanovna.com/?page_id=90 Awesome.


Well, they are different tools for different situations.

I found, for what I do, having a vector network analyzer was more useful that having a spectrum analyzer. Specifically, measuring the SWR of antennas and measuring the resonance frequency of filters.


Similarly can anyone recommend an affordable oscilloscope? Ideally mixed signal and PC attached.

Picoscopes are great and very affordable on a work budget, but a bit much for my home budget particularly if you want a mixed signal one.


I’ve been very happy with my Siglent 4 channel/100 MHz scope (with logic analyzer but I don’t have the $200 pod so I don’t use that). The scope was about $400 and I find it worth the investment. It’s on the same level as the popular Rigol lines but I don’t like their UIs very much (too chinesium for me?).


Get a used TDS-2xxx series used on ebay. I prefer Tek scopes, great trigger, and the TDS 210, TDS220 and their ilk continue to work very well. As to PC attach, yes, you can do that, but that will need some s/w.

Many people like the newer Chinese scopes; see https://youtu.be/S8jrpCoZyx8?si=oaI_gxOylYhOSp-m but I have only limited experience with those. Their UI seems less obvious than Tek scopes.

The other very important specs besides what you've mentioned are # of channels, and highest operating frequency. Others today would be how fast is the ADC, how many bits, storage depth, post-capture analysis capabilities, and so much more.


I have a lot of experience with Tek, HP and Siglent scopes. The Tek scopes are IMO some of the least intuitive.

But if you want to remote control the scope, stay away from the Chinese ones: that part of the FW is often very buggy.


What frequencies, how many channels of analog/digital, what bit depth, how much memory, etc? What is your actual application? And what do you mean "PC attached" here? What is your budget?

I don't think you are going to find much for less than a Picoscope.

Maybe something like the Analog Discovery 3? Under 400 USD, 2 channel oscilloscope (30 MHz), 16 channel digital, 2 channel arbitrary waveform generator (12 Mhz) https://digilent.com/shop/analog-discovery-3/

Rigol and Siglent both make mixed signal scopes that will do two channels analog at 100MHz and 16 channel digital for ~1k USD.


I wasn't familiar with the the Analog Discovery. Seems good value as it covers a lot of bases in one go.

30 Mhz is a bit low, but would cover the lower speed digital stuff which is what I need a scope for most of the time.

Two scope channels, some logic analyser channels, ideally 50 MHz, ideally 12 bit. That works at as about £500 from Picoscope which is pretty cheap. I was astonished at these Spectrum Analyzers and I was wondering if there was something from china at a fraction of that.


The TinySA is kind of like a tiny radio, just tuning through the channels and measuring how loud at each frequency. And it managed to leverage an exiting chip (designed for other purposes), which is how it got to be so cheap.

This is a great explanation of the signal path: https://www.youtube.com/watch?v=z63cXhYzS1A


Related: I recall seeing USB scopes very cheap like ... 5 years ago, maybe 6?

Are they any good? In the market for a very cheap 'scope - think, looking at i2c signals, 0v-5v analog signals from (for example) a temp sensor, etc.

Is the buspirate still around?


keysight(leaders in the industry) released a model(EDUX1052A) for hobbyists starting at $500.

https://www.keysight.com/us/en/support/EDUX1052A/oscilloscop...

They also have DSOX1202A & DSOX1202G for ~$1k -> ~$1.2k


Analog discovery series is cheap and good enough for a lot of tasks.


I've found Analog Discovery true to its name -- great for exploring analog. The scope portion is limited in channel sensitivity and frequency. It's also a bit of a kludge, in that the probes attach via a 2x20 (?) front-panel 0.1" center connector to an adaptor board that has BNC females for the scope probes.

I have one of those (AD2; there is a newer AD3 available), and it's quite a lot of 'stuff' in one package. I wish I had one when I was learning EE. But these days, I use them as 'data acquisition and control' modules to generate and capture signals under program (Python) control. I think of them sort of as a fancy Arduino -- although it can do many more analog tricks. Recommended.


The related NanoVNA has been transforming amateur radio, now almost everyone that can afford a radio can afford a VNA that lets them characterize, tune, and repair antennas and other RF components.

Gone are the days when you had to beg a club member with a $10,000 MSRPed bench VNA in the back of his truck to swing by. You can pull a VNA out of a bag while still up the tower.

High-Q antennas designs that are sensitive to construction and mounting are much more realistic to use when you can VNA them in situ.


Anyone know of a hardware spectrum analyzer that renders with a cruder display, only showing the main harmonics/or harmonics above certain thresholds as straight lines? I would love something like that for FM synthesis intuition. idk if when looking i found one i liked even in software :(


Someone (actually probably someone commenting on this threads) , with way too much money and time, has been playing catch me if you can. They use a blend of retail analytics, ambient noise and other NLP tuning features of phones and actual visuals I haven’t figured out yet. I had a bug sweeper over to the home, and he basically ran away as fast as he could after realizing I had a sane witness with me - and tons of screen shots.

My question is if someone is actually using advanced satellite surveillance capabilities to augment their running joke by looking in my window, (which can’t be ruled out in my world unfortunately), would one of these devices pick up the RF?

I was supposed to have gone crazy blah blah blah while they tell me what is on my counter in a mobile game.

Sadly, we decided they also are just leveraging the housekeeper and making some good guesses in a few cases. Yet there is one window they kept coming up with what was in front of it. No visible cams in line of sight.


The whole thing is pretty nuts. I'm sure most would just ignore. One of the individuals involved did something quite criminal and deeply personal to a family member, so I am genuinely looking for an answer on how to sweep for possible eves-dropping in this scenario. I have actually worked with people who have access to satellite and security product testing (not privacy filtered consumer services) and they could have motive.


Reminds me of that other small and cheap spectrum analyzer the RFExplorer. That's been on the market for 10 years or so. It has a similar need to be careful with strong signals.

I didn't know of this one, I'll check it out. It looks way better and the basic one is a lot cheaper too!


The TinySA is excellent for finding sources of RFI, although you want to use a small yagi or loop antenna.


I wish I had it when I was having an RFI issue in my neighborhood. I ended up with my RTL-SDR hooked up to my mac with a homemade copper-on-tape-on-cardboard yagi, and I looked like I was a tinfoil hat away from being needing to be put away.

Still would have looked nuts with the TinySA, but... less so.


Had this issue before and having new more advanced ones now. Gotta say one life saver has been Cisco Meraki’s Air Marshall for detecting at least Bluetooth and WiFi interference. Still hard to tell the source - with just a handful of neighbors there are a ton of unidentifiable devices (just MAC addresses) as the internet of things landscape continues to grow.


Did you find the source of the issue?


I was attacked quite deliberately in another city and was unable to find the source. It was in a high rise, and GSP with Kismet was marginally useful. Precision was not possible.

I was able to stop the rogue attacks with Cisco Meraki. This was extremely beneficial.

Since I moved, I have had to change channels a few times due to interference. The dashboards in the Meraki, are great at visualizing and identifying sources.

I also made it a point to look ridiculous and walk around to meet the neighbors to understand what is not “rogue” and tell them I was having problems. This was to build an inventory and ensure I didn't accidentally jam something thinking it was a rogue attack. I let them know to inform me if they experienced problems.

Clearly someone was sending waves of wireless hackers my way as a poorly defined joke. Despite efforts to get inventory of my surroundings, there are still a ton of unknown devices in the area I cannot identify with precision, and the area is not highly populated. No one knows how many access points and devices they are running any more for smart lights, cams etc.

Finding the source as far as I can tell may be more feasible here w GPS receiver - yet I have not had a need.


I narrowed it down to something around my next door neighbor's house. The issue was there was something broadcasting a signal that covered the same range that my car key fob did, so I couldn't lock/unlock my car unless I was right up on it.

But the signal was intermittent, and I talked to all the neighbors in all three units, and none had anything that sounded like it could be the culprit. It eventually just stopped happening, so I never tracked it down.


This looks exceedingly cool.

I probably don't have a use for this type of thing, any more, but, at one time, I would have snatched one up, immediately.


Can you use the nanoVNA hardware tor this by just loading the firmware? They look identical.


Anyone know a signal generator that can do 60.000 Hz?

I used to use the HP 3310A but they are analog and really old now


Any decent digital one should be able to do that I imagine. I've got an entry-level Siglent[1], it can do 1 microHz and up. Or am I missing something?

[1]: https://www.siglenteu.com/waveform-generators/sdg1000x-serie...


Thanks. A lot of the hobbyist level ones did not do low frequencies at all or precisely enough to compare to electrical grid frequency

That one for 350 euros looks good


The tinySA can also be used for that, it's not only a spectrum analyzer, it can also generate signals and optionally modulate those for you.

edit: https://tinysa.org/wiki/pmwiki.php?n=Main.Specification here says it works from 100kHz for the low output. When I just tried it did let me select 60kHz and turn it into output mode. Haven't hooked it up to a scope to see what it does. Sorry no time to set it all up now. 60kHz is very low though, if you browse AliExpress then I'm sure plenty of signal generators will offer that for a really low price (cheaper than the tinySA)

edit 2: Sorry my European brain kicked in and missed you are looking for a 60Hz one that is very precise and not a 60kHz one. I'd better get some sleep.


Check out the function generators from FeelTech on Amazon or AliExpress, like the FY6900 or FY6800. They’re cheap in a flimsy plastic case, but they’re good enough for many applications.


Im not sure how well it would work, but for a low cost solution try your PC's sound card. Reasonably low distorsion and sufficient frequency accuracy.


wow, cheap.




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