I think projects like that would have been a godsend 2-3 decades ago, when even a basic oscilloscope costed as much as a used car.
Nowadays, very good oscilloscopes with 200 MHz bandwidth, good user interfaces, and responsive displays are selling for $300 - I'm talking Siglent, Rigol, UNI-T. So the merits of DIYing something much worse just aren't quite there. It's that one piece of equipment you use to troubleshoot all your other designs, so you want it to be dependable, easy to use, and accurate.
This is not to say it's not a fun, geeky project to work on and publish... but you know, only once you have a real oscilloscope. If you're just setting up, do yourself a favor and spend a bit more money on this. The remaining equipment is not nearly as critical.
> very good oscilloscopes with 200 MHz bandwidth, good user interfaces, and responsive displays are selling for $300
This is a very strong first world POV. Those U$D 300 rank pretty high across world's minimum salaries [1], not to mention that prices can very likely double in countries like my own.
Moreover, a large % of people that can really get a very good use of this (Kids in high school) usually have a lot less money at their disposal, and we are not getting into collaterals like building your own and learning how it works.
Want to keep a distractable 14 year old busy for an hour? Give him or her some wire, a cheap meter, a battery, some switches and LEDs. Want to possibly change that kid’s life? Give him the above, plus a scope, and hook it up to a music player playing his favorite song.
That's a very fair point, but it's also fair to discuss things with a 'first world' point of view. The same way it can be humourous or eye-opening to point out something's a 'first world problem', but if that's where you live then that is a problem, that is something you're looking to address.
We're all looking to do the best we can from different baselines.
Note: the intention of this comment is just to be informative.
I did a quick search in my country's Mercado Libre (the local Amazon, we could say) and the cheapest available one, Fnirsi-138 Pro [1] goes for a price of aprox. 50 USD [2]
what makes the Flea-Scope so particularly interesting to me is that you get I think 9 channels worth of digital inputs all at once. That is hard to beat for the price.
Regarding raw specs, it seems to be much better in most regards compared to the mentioned Fnirsi-138 Pro.
So starting with nothing at all, what is the total cost of ownership for the flea -cope? My guess, its over $300, (if $300 is your annual salary, your existing phone will probably not cut it). And for comparison, standalone toy oscilloscopes (<10Mhz bandwidth) go for $30 and under (some $11), with screen, on AliExpress. And a "decent" one, like OWON, is around $150.
The problem is, with a toy scope, you aren't really gonna know if what you're measuring is real. This might be useful as a kit to build to learn how to program microcontrollers, or measure audio signals (the $11 one, or the mic on your phone can do this), but a bad scope will generally cause more problems for the hobbyist. When you get near the limit of a scope's bandwidth, the signals get really messy and full of artifacts. Arduinos run at 8-16Mhz, so you're gonna hit a wall really quickly and once you can't rely on the output, the investment will be lost.
Where's that guess coming from? The scope is $18, the optional probe from elecrow is $5 extra. You most definitely have either an android phone or a laptop/PC with a browser from the last ten years already. As such the cost is pretty minimal.
Say you bought a set of these kind of test probes with hooks at the front. A set would maybe cost you $10. Now you can use all your 9 channels.
I don't understand your price calculations.
Every scope out there has an upper limit in terms of speed. If you have no use for it, don't buy it. This oscilloscope is first and foremost a learning resource.
"This is a very strong first world POV. Those U$D 300 rank pretty high across world's minimum salaries "
My point, since I was replying to a poster who said the above, was if you are making $300 a year, you don't have a laptop. So, if you read my assumption, that you don't have a laptop, android phone or laptop, and you are making < $1000 USD a year, the Flea-Scope will cost more than a decent one with a built in display and much more than a ~2mhz toy intro oscilloscope ($11 on Aliexpress) [1]
I could also very well reply with just the quote above.
I think there's a difference in options at $200/$20/$2 (see elsewhere in this thread) just in lowering the bar to entry to the point of triviality. I'm not spending $300 without knowing exactly what I want it for, $20 is easy, $2 is an impulse buy.
Fair enough, but on the flip side - you either want to get into electronics or not. If not, there's no real point in spending the money, even if it's $2. If you do, then you probably don't yet have an understanding of what features you need, and the cheapest option will actually hold you back.
Some specific issues: first, the number of inputs. A lot of circuit debugging is about "let's see how signal A looks like when signal B happens" (B might be a bus clock or something like that). So, a lot of the time, you need two inputs, not one.
Second issue: even hobby MCUs generally run faster than 4 MHz, so you might need more bandwidth to monitor I/O, even for old-school Arduino stuff - let alone RP2040.
Third issue: for anything analog, from audio equipment to household appliances, the 0-6 V input range just doesn't cut it.
I'm not trying to dunk on this project: I think it's about as good as you can do for the price, and it's clearly a passion thing for the author. But if you can afford it, and if you want to learn electronics, a "real" oscilloscope is almost certainly a better deal.
> you either want to get into electronics or not. If not, there's no real point in spending the money, even if it's $2
It's fuzzier than that; there are hobbies that look fun but I can't decide if I want to fully invest into them, but having a cheap, but not-great equipment is a good stepping stone. Besides, beginners won't have the skill to fully use fully-featured pro-level-gear. A cheap soldering iron is great for those looking to get their feet wet; sure the lack of precise temperature control can be a hinderance, but investing in an expensive soldering station is wasteful if one decides that it's not really for them.
Ironically, beginners would benefit the most from a good soldering station, proper liquid flux and leaded solder. Seasoned electronics guys can probably solder anything with a cigarette lighter and a scrap piece of metal, but using proper tools makes a huge difference when you're just starting and might mean not dropping the hobby altogether because of a lousy first experience..
> Seasoned electronics guys can probably solder anything with a cigarette lighter and a scrap piece of metal
This made me laugh. In college in the late 80's I repaired a roommate's not-quite vintage C64 fastloader cartridge with a bad wire bodge using a lighter and the tine of a dining hall fork...
> having a cheap, but not-great equipment is a good stepping stone.
I don't agree for something like this. The problem is that beginners often don't understand how to deal with the limitations of equipment--all they understand is that something is wonky and they don't know how to fix it.
In addition, bad equipment can make your initial impressions so painful that they prevent you from going further. Oscilloscopes, cheap soldering tools, etc. all have this effect. It's not unique to electrical engineering though--super cheap guitars are painful to play while something just $150 more is dramatically easier to deal with.
Where cheap equipment shines is when a beginner has been at it long enough and becomes "dangerous". They know just enough to do things but not enough to avoid things that will destroy their equipment. That's when the $20 "whatever" is a blessing because you'll get annoyed but you won't be distraught if you blow it up. Even as someone experienced, I semi-regularly destroy a $10 logic analyzer because the circuit I was analyzing wasn't doing what I thought it was (of course, this is mostly laziness--since the analyzer is merely $10 I don't take the time to double check things that I would if I were to put my Agilent analyzer on it)
> Besides, beginners won't have the skill to fully use fully-featured pro-level-gear.
Quite often, pro gear is better for beginners. For a beginner, an "Auto Scale" button on their scope that does the right thing is a godsend. Even I use it all the time. Sure, I can dial the signals in quickly, but "Auto Scale" does the right thing 99% of the time with a single button press.
Even with soldering, a Metcal system maintains the temperature exactly where you need it. You don't have to worry about having too much/not enough heat on the component you are working with. You don't have to worry about the calibration on your soldering station. A Metcal will pump a lot more energy into a big hunk of transformer and a lot less energy into a QFP integrated circuit. Sure, someone experienced can adjust for this on a Hakko, but a beginner is having a tough enough time getting solder down and the soldering iron in the right place without knocking the IC all over the place and doing it all through a microscope.
> investing in an expensive soldering station is wasteful if one decides that it's not really for them.
Used Metcal soldering systems are "expensive" ($250-$500), but they also resell for almost the exact same amount you bought them. Cheap soldering stations won't resell for anything. So, all the money you spend on a cheap station is lost if you decide not to go further while the expensive station cost all gets recovered.
Regarding soldering, I think a Pinecil [1] is a suitable soldering iron for beginners. It's affordable and since the heating element is in the tip it will make soldering much easier compared to older irons or soldering stations.
Could someone recommend one starting out (something beginner could use and has enough, good functions for continued use into later advanced projects without running into limitations for 'most' projects).
Would be helpful to understand the what limitations might be encountered such at the frequency.
Buy a Pinecile[1] from Pine64. It's currently discounted to $25.99 (excluding shipping), and it's both cheap and has a great feature list that makes soldering a breeze.
Rich designed it with trigger IO pins to be able to easily chain them. While the UI doesn't support managing multiple Flea-Scopes at once, you can just open the UI multiple times, which does seem like a reasonable option to me.
As as others have pointed out before, there's just no alternatives in this form factor. The scope is tiny, and for what it is it packs quite a punch. 3.3V and 5V are standard logic levels which will suffice for quite a lot of basic probing. Being made for students, it does likely everything that would be required of it in an educational environment. How well this pans out in real-life we'll see soon.
Granted that with enough money and space at hand there are much better options out there.
I got one recently, and it's been a pleasure to use. My only regret is not getting the 4 channel version, though I've only needed 2 channels so far. But at my workplace, I've found that an extra channel is the thing that helps me solve a problem, more frequently than higher performance does.
I'm an old timer so I'm familiar with the traditional scope front panel, but have come to like the touch screen for changing settings.
Perhaps my only gripe is how long it takes to boot.
I get around the long boot time by never turning mine off lol
I used to thing touch screens on scopes were a gimmick. Then I used one to name a signal quickly and easily for a trace capture. After that I was hooked.
Also - be sure to upgrade the firmware if you haven’t yet. They fixed that annoying bug where it doesn’t remember your probe settings between power cycles!
Edit: Updated the firmware. Works. First time I noticed the problem, it was at my desk, and I assumed it was because the scope was plugged into a switched power outlet, and I was habitually turning off the lights when I left the room. Only after a couple of tries did I discover that it was an actual bug.
HN: Come for the arcane programming topics that are over my head, stay for fixing my scope!
I started out buying little cheapy toy scopes when I started tinkering with electronics and I wish I’d just waited and saved for a proper one.
Way more useable, especially having proper probes.
I get it - I’m in the first world, unlimited money and privilege, yada yada - but if you think you realistically can save $400 USD for a scope like this, you should.
In his presentation video [0] Rich explicitly states that his goal is to make electronics approachable for the younger generation. A low barrier of entry in almost all directions is a key component in that in my opinion.
It’s a matter of perspective, though. For a white collar professional in the US? Sure. For most of the world’s population, the distinction between $300 and $18 is extremely consequential.
Right. $18 is 6% of $300. For that to be a difference of little consequence, $300 must be an expenditure of little consequence. In the other direction $300 is 6% of $5000. There are people— a number of whom likely frequent this forum— for whom a $5000 expenditure isn’t particularly consequential, and getting an OK thing for $300 doesn’t make sense when you can get a pretty good thing for $5000. That certainly doesn’t mean someone being able to offer a useful version of a $5000 thing for $300 has no merit.
I see this sort of thing in amateur radio all the time. “Why on earth would anyone just starting out consider getting a Baofeng radio for $20 when you can get a better quality name brand equivalent for $200?” Well because $180 is a whole lot of money for a whole lot of people.
I think there's something to be said for the form factor here though: I can see myself owning one of these just to take as part of a kit if I expect to need to do some troubleshooting away from my typical workspace.
I have a cheap handheld oscilloscope (ZOYI ZT703S, ~$80) that I find very convenient to have around. It's the size of a multimeter, runs on a battery and works well enough that I don't feel too limited by it.
Nowadays I have a fairly decent Rigol scope, which suffices for my modest and infrequent needs. But back when I was a teenager I had very little money but plenty of time. A cheap DIY option would have made a lot of difference to me. I hope project this makes a difference to people on a budget, of whatever age.
Nowadays, very good oscilloscopes with 200 MHz bandwidth, good user interfaces, and responsive displays are selling for $300 - I'm talking Siglent, Rigol, UNI-T. So the merits of DIYing something much worse just aren't quite there. It's that one piece of equipment you use to troubleshoot all your other designs, so you want it to be dependable, easy to use, and accurate.
This is not to say it's not a fun, geeky project to work on and publish... but you know, only once you have a real oscilloscope. If you're just setting up, do yourself a favor and spend a bit more money on this. The remaining equipment is not nearly as critical.