4 ms·

Hi all, new here. 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 fi

Hi all, new here. 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/ 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

just_mc 2y ago
What you've done is awesome. Ignore the haters and build your mosquito scope.
Reviving1514 2y ago
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. Great tool. Thank you.
burgerone 2y ago
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.
- rtestardi 2y ago
  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!
kjs3 2y ago
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.

just_mc 2y ago

What you've done is awesome. Ignore the haters and build your mosquito scope.

Reviving1514 2y ago

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. Great tool. Thank you.

burgerone 2y ago

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.

rtestardi 2y ago
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!

kjs3 2y ago

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.