I think the posted title need to be improved and updated to include function or waveform generator instead of just More.
Perhaps because of that most of the comments here just focusing in the oscilloscope part.
As any who has dabbled with electronics know your typical workbench is normally consist of oscilloscope, logic analyzer, waveform generator, digital multi-meter and power supply normally 12V DC.
It seems to me this little $18 hybrid signals scope/generator can do almost all of these functions, and since they are integrated on the same device you don't need to synchronize them which is a big plus.
For old school HP/Agilent/Keysight electronics workbench discrete solutions can easily cost tens of thousands dollars, no kidding.
The modern version of this is the Digilent Discovery Pro 3000/4000/5000 series with price tags of several thousands dollars. They are described as the All-In-One High-Speed Mixed Signal Oscilloscope, Function Generator, Power Supply, and DMM. The cheaper version of this Digilent Discovery 1/2/3 series that cost around $400. But the latter is quite bandwidth and resources limited thus more comparable with the Flea-Scope [1].
[1] Digilent Analog Discovery 3 vs. Digilent Pro ADP2230 [video]:
One post below might be a bit misleading -- it's just 18 Msps, not 100 -- so think of it as good for signals up to 1 MHz or so with decent fidelity... And it uses a PIC32, not STM32. It is 12 bit ADC, but the noise floor makes it more like 10 or 11. A cool thing is it also does digital capture and waveform generation at the same time, but clearly it's all pretty simple...
My goal was to be able to get these in a classroom at every seat, where there's already a computer or tablet or chromebook, and have it "just work"... The thing I like the best by far, though, is javascript access -- you only need a webpage for the GUI -- no software install or app store or anything!
To go deeper for the classroom experiments, you can use a different "deep dive" webpage with a command-line UI and log in interactively and take control of all the pins programmatically in BASIC, and even configure the board to autorun a BASIC program on power-up... You can make a "simon" game with 4 switches, 4 LEDs, a buzzer, and about 100 lines of code... Or with a thermocouple and an op-amp and a solid-state relay, you can make a cool toaster oven temperature controller for reflow soldering -- which is how I built all the prototypes... The nice thing is the javascript access on the host comes for free still, and so BASIC can talk directly to the host computer (e.g., running python or powershell)! Examples are here: https://rtestardi.github.io/pages/
I have also had fun with automotive applications for Flea-Scope -- it is so easy to just bring out a phone or tablet and measure a crankshaft sensor -- and without it you're just guessing and replacing components from some diagnostics flowchart...
As for licensing, it is all open source, and anyone can rebuild it (and even sell it). There is a patent on the internal BASIC, but there is also a perpetual license to the software builds I have made and tested and released -- conceivably you could build the scope without BASIC at all -- it is unneeded except when you use the board in "deep dive" mode for BASIC programming.
If there is interest, I have toyed with the idea of making a Mosquito-Scope, with 2 channels and selectable input amplification (for sub-millivolt signals) based on the still-brand-new dsPIC33A, which is actually cheaper and faster than the PIC32MK.
I know you are looking at this for education but I've actually ordered two to toss in my travel bag for when I visit factories to handle manufacturing bringup.
I think the low cost of the flea-scope justifies sticking to just one analog input per device, even with a successor, provided that the interface gets a little bit of an upgrade to be able to handle multiple scopes at once.
This would retain the small form factor and would keep the design free from compromises.
Wow, I love this idea -- I bet I could make an alternate UI display two analog waveforms from two devices instead of analog and digital from one... I don't think it would even require threading complexity, since the second device will only trigger after the first already has!
My goal was to be able to get these in a classroom at every seat
This is really amazing and you are to be commended. And you've clearly thought hard about what can make that successful. There's just no replacement for every student having their own setup to experiment with. My first exposure to o-scopes, the whole class was basically sharing one giant Tek 7k series scope, one of the best of the time (with commiserate cost), and while I did learn the basics, it wasn't till I had my own much, much less feature filled scope did I learn it well enough to be useful.
N.B.: Since you're new here, I'll just warn you that it's SoP around here that any time anyone posts an "I built this", the comments will be filled with nitpicks about trivial issues presented as massive errors, people telling you how much better they would have done it if they ever got around to doing it and how they got something cheaper on alibaba so why bother. And, of course, you should have written it in Rust. Just ignore that stuff.
For about the same price ($13), I'm happy with this logic analyzer I bought through amazon[1] a month ago. I spent more on probes[2] ($24) than I did the analyzer. ;-)
To power it, I'm using SigRock/Pulseview[3], which sees it as a compatible clone. It's wild to be able to see signals a few tens of nanoseconds wide so cheaply.
I have this exact one, and I don't reccomend using it with the Saleae Logic software, it constantly drops out and has issues enumerating. Haven't tried sigrock yet.
> I don't reccomend using it with the Saleae Logic software
The Saleae software is designed for use only with Saleae products. Anything else is a clone.
I wouldn’t be surprised if they intentionally made the software frustrating and buggy to use with clones. The software (which is great) is funded by hardware purchases.
Yeah, those are awesome. I found that a great use was to profile microcontroller code. Setting various GPIO pins high / low around critical sections of code. Then you can see the results in SigRock.
Mandatory caveat: beware of ground loops when using a USB oscilloscope! Most budget USB scopes share ground with your PC via the USB port. If you're probing high-voltage circuits (e.g., mains power, switching supplies), this can create a dangerous potential difference, risking damage to your computer or worse. Some scopes offer isolated inputs, but if yours doesn’t, use differential probes or an isolation transformer. Otherwise, you might end up debugging your laptop’s fried USB controller instead of your circuit.
On a related note, I once fried the built in audio hardware of my laptop. I even saw smoke coming out one of the vents. The rest of the computer survived.
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.
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.
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.
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.
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.
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.
edit: parent was heavily edited, so this comment makes less sense now.
Note that calling this FOSS is completely inaccurate. Some parts are all rights reserved, some are public domain and some are only available for non-commercial use.
Public domain is not open source, and especially not free (as in freedom). Restricting commercial use is also not free. At best, this project is partially source-available.
> Public domain is not open source, and especially not free (as in freedom).
The Free Software Foundation (FSF) and Open Source Initiative (OSI) recognize public domain software as "free software," but not as open source, but as I understand it, it's not that different from MIT licensed software. Someone can take MIT licensed code, make changes, sell the resulting binary as proprietary code and no one else is allowed to take that binary and sell it as theirs. There are some subtle other differences, but MIT licensing doesn't require other people's changes get contributed back out as open, same as public domain.
The only thing more frustrating than a rustacaen redefining "safety" to suit their purpose is a Stallman discipline redefining freedom to mean something totally weird. Something in the public domain is not free? Give me a break.
I can recommend this gizmo for people just starting to learn about electronics. I got one in Hackerbox 102[1] and found it to be a good value in terms of bandwidth vs cost.
In talking about it to my engineering friends I got the somewhat expected dismissive "well its just a toy" kinds of comments, and to be clear it has a lot of limitations, but within those limitations it also has a lot of opportunity to teach people about things like analog electronics which are best learned by looking at the signals. And given that so many people starting out don't even know why they might need an oscilloscope, its a pretty good way to introduce the tool without the huge learning curve of features you may not use for the first year of your learning process :-).
And then when it comes time to pick one of the many really excellent choices of bench tools, you won't be completely clueless about what the functions of the oscilloscope do. So for $20 I consider it a good value and have recommended it to people who were just starting to learn about these things.
Readit News
I think the posted title need to be improved and updated to include function or waveform generator instead of just More.
Perhaps because of that most of the comments here just focusing in the oscilloscope part.
As any who has dabbled with electronics know your typical workbench is normally consist of oscilloscope, logic analyzer, waveform generator, digital multi-meter and power supply normally 12V DC.
It seems to me this little $18 hybrid signals scope/generator can do almost all of these functions, and since they are integrated on the same device you don't need to synchronize them which is a big plus.
For old school HP/Agilent/Keysight electronics workbench discrete solutions can easily cost tens of thousands dollars, no kidding.
The modern version of this is the Digilent Discovery Pro 3000/4000/5000 series with price tags of several thousands dollars. They are described as the All-In-One High-Speed Mixed Signal Oscilloscope, Function Generator, Power Supply, and DMM. The cheaper version of this Digilent Discovery 1/2/3 series that cost around $400. But the latter is quite bandwidth and resources limited thus more comparable with the Flea-Scope [1].
[1] Digilent Analog Discovery 3 vs. Digilent Pro ADP2230 [video]:
https://youtu.be/yr9SGxiBAnI
There's a lot of unique, interesting and useful features this offers, all of which are deserving of a spot in the title...
Edit: Seems like I have lost the ability to change the post title. Unfortunate
The Flea-Scope is only 4 MHz single channel so this more similar to the older ZT702S 10 MHz version.
[1] EEVblog 1597 – Zoyi ZT-703S $80 2CH 50MHz Oscilloscope/Multimeter Review:
https://www.eevblog.com/2024/02/07/eevblog-1597-zoyi-zt-703s...
One post below might be a bit misleading -- it's just 18 Msps, not 100 -- so think of it as good for signals up to 1 MHz or so with decent fidelity... And it uses a PIC32, not STM32. It is 12 bit ADC, but the noise floor makes it more like 10 or 11. A cool thing is it also does digital capture and waveform generation at the same time, but clearly it's all pretty simple...
My goal was to be able to get these in a classroom at every seat, where there's already a computer or tablet or chromebook, and have it "just work"... The thing I like the best by far, though, is javascript access -- you only need a webpage for the GUI -- no software install or app store or anything!
To go deeper for the classroom experiments, you can use a different "deep dive" webpage with a command-line UI and log in interactively and take control of all the pins programmatically in BASIC, and even configure the board to autorun a BASIC program on power-up... You can make a "simon" game with 4 switches, 4 LEDs, a buzzer, and about 100 lines of code... Or with a thermocouple and an op-amp and a solid-state relay, you can make a cool toaster oven temperature controller for reflow soldering -- which is how I built all the prototypes... The nice thing is the javascript access on the host comes for free still, and so BASIC can talk directly to the host computer (e.g., running python or powershell)! Examples are here: https://rtestardi.github.io/pages/
I have also had fun with automotive applications for Flea-Scope -- it is so easy to just bring out a phone or tablet and measure a crankshaft sensor -- and without it you're just guessing and replacing components from some diagnostics flowchart...
As for licensing, it is all open source, and anyone can rebuild it (and even sell it). There is a patent on the internal BASIC, but there is also a perpetual license to the software builds I have made and tested and released -- conceivably you could build the scope without BASIC at all -- it is unneeded except when you use the board in "deep dive" mode for BASIC programming.
If there is interest, I have toyed with the idea of making a Mosquito-Scope, with 2 channels and selectable input amplification (for sub-millivolt signals) based on the still-brand-new dsPIC33A, which is actually cheaper and faster than the PIC32MK.
-- Rich
Great tool. Thank you.
This would retain the small form factor and would keep the design free from compromises.
This is really amazing and you are to be commended. And you've clearly thought hard about what can make that successful. There's just no replacement for every student having their own setup to experiment with. My first exposure to o-scopes, the whole class was basically sharing one giant Tek 7k series scope, one of the best of the time (with commiserate cost), and while I did learn the basics, it wasn't till I had my own much, much less feature filled scope did I learn it well enough to be useful.
N.B.: Since you're new here, I'll just warn you that it's SoP around here that any time anyone posts an "I built this", the comments will be filled with nitpicks about trivial issues presented as massive errors, people telling you how much better they would have done it if they ever got around to doing it and how they got something cheaper on alibaba so why bother. And, of course, you should have written it in Rust. Just ignore that stuff.
To power it, I'm using SigRock/Pulseview[3], which sees it as a compatible clone. It's wild to be able to see signals a few tens of nanoseconds wide so cheaply.
[1] https://www.amazon.com/dp/B077LSG5P2
[2] https://www.amazon.com/dp/B0CLB63GL3
[3] https://sigrok.org/wiki/PulseView
The Saleae software is designed for use only with Saleae products. Anything else is a clone.
I wouldn’t be surprised if they intentionally made the software frustrating and buggy to use with clones. The software (which is great) is funded by hardware purchases.
I think the firmware might have some timing issue with the USB bus, and just a few extra nanoseconds of a 2 foot long cable seems to break it.
Seems like magic.
Link doesn't work.
Nowadays, very good oscilloscopes with 200 MHz bandwidth, good user interfaces, and responsive displays are selling for $300 - I'm talking Siglent, Rigol, UNI-T. So the merits of DIYing something much worse just aren't quite there. It's that one piece of equipment you use to troubleshoot all your other designs, so you want it to be dependable, easy to use, and accurate.
This is not to say it's not a fun, geeky project to work on and publish... but you know, only once you have a real oscilloscope. If you're just setting up, do yourself a favor and spend a bit more money on this. The remaining equipment is not nearly as critical.
This is a very strong first world POV. Those U$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.
[1] https://en.wikipedia.org/wiki/List_of_countries_by_minimum_w...
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.
We're all looking to do the best we can from different baselines.
For the purposes you are talking about you can get what you need with one of the $20-40 scopes.
Those ones also tend to be portable and more rugged which is what you need if you don’t have a full blown lab to keep a nice oscilloscope in.
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.
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.
- 12 bit ADC frontends
- Actually usable touchscreen inputs
- Super simple to drive remotely over a network connection (though getting the IP address with just the touchscreen is a little tricky)
- USB-C power input - you can run it from a battery pack if you like!
- All the essential decoders built in for free (I2C, SPI, UART)
- VESA Mountable - I got a monitor arm to gain back some desk space (awesome feature)
- Very, very easy to hack one of the budget models and upgrade it to a 250MHz model :D
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.
[0]: https://www.youtube.com/watch?v=sbRXDkHS_V0
I think it does have its place even today.
Deleted Comment
https://github.com/rtestardi/StickOS2/blob/main/license.txt
https://github.com/rtestardi/usbte/blob/master/LICENSE
Note that calling this FOSS is completely inaccurate. Some parts are all rights reserved, some are public domain and some are only available for non-commercial use.
Public domain is not open source, and especially not free (as in freedom). Restricting commercial use is also not free. At best, this project is partially source-available.
The Free Software Foundation (FSF) and Open Source Initiative (OSI) recognize public domain software as "free software," but not as open source, but as I understand it, it's not that different from MIT licensed software. Someone can take MIT licensed code, make changes, sell the resulting binary as proprietary code and no one else is allowed to take that binary and sell it as theirs. There are some subtle other differences, but MIT licensing doesn't require other people's changes get contributed back out as open, same as public domain.
Dead Comment
How so? There are no restrictions on use or distribution.
> Restricting commercial use is also not free.
I agree, and I would include neutering any commercial uses, in which case GPL is non-free.
https://patents.google.com/patent/US8117587B1
In talking about it to my engineering friends I got the somewhat expected dismissive "well its just a toy" kinds of comments, and to be clear it has a lot of limitations, but within those limitations it also has a lot of opportunity to teach people about things like analog electronics which are best learned by looking at the signals. And given that so many people starting out don't even know why they might need an oscilloscope, its a pretty good way to introduce the tool without the huge learning curve of features you may not use for the first year of your learning process :-).
And then when it comes time to pick one of the many really excellent choices of bench tools, you won't be completely clueless about what the functions of the oscilloscope do. So for $20 I consider it a good value and have recommended it to people who were just starting to learn about these things.
[1] https://hackerboxes.com/collections/past-hackerboxes/product... and the experiment guide https://www.instructables.com/HackerBox-0102-Flea-Scope/