3 ms·

Great idea! Even though this has already been created -- I think it would be an interesting project to attempt to create one's own oscilloscope watch... Funct

Great idea! Even though this has already been created -- I think it would be an interesting project to attempt to create one's own oscilloscope watch... Functionally, it's just a 3D printed watch case, watch bands, an 8-bit microcontroller, LCD screen, battery, oscilloscope probes, a little bit of custom software, and some circuitry to block excessive currents... Oh sure, it would probably be much easier (and cheaper!) to buy this than make one -- but I think it would be highly interesting to learn what goes into making one... Any serious student of electronics should, as a project, make their own oscilloscope... it would be a great teaching project! All of that being said, kudos to the inventor of this excellent oscilloscope watch, it looks really cool -- you'll probably sell a whole bunch of them! So, well done!

pjc50 3y ago
> 8-bit microcontroller Scope with 8-bit resolution is a logic analyzer with delusions of grandeur. 16 bits is realistically the useful minimum; if you want to do scaling in digital rather than the analogue front-end, you'll want 24 which is significantly more expensive. So you want at the very least a 16-bit microcontroller and in practice just an ARM. Next question is what you want to do about capture rate. 20MHz would be nice, the standard for thirty year old CRT scopes, but realistically audio frequency or 1MHz is going to be about the most you can do. TBH, something that can capture I2C and SPI and audio frequency does actually cover some useful use cases. Might be fun to give it a 3.5mm stereo jack for the probes or direct audio input. > some circuitry to block excessive currents The scope is high-impedance so this shouldn't normally be a problem. (You're not going to have a 50 ohm BNC input on a watch). You might want to think about voltage, but the sort of person who decides they want to look at the mains frequency cycle on a device strapped to their wrist won't be deterred by warning stickers.
- planede 3y ago
  8-bit micros can and usually have wider than 8-bit ADCs. Having said that you are right, I don't expect this ADC to work as a decent oscilloscope.
- ben_w 3y ago
  > You might want to think about voltage, but the sort of person who decides they want to look at the mains frequency cycle on a device strapped to their wrist won't be deterred by warning stickers. You've just reminded me that when I got an oscilloscope to play around with, I found out — by accident and to my surprise — that my body was coupled to the mains frequency strongly enough to see it clearly just by touching the probe.
- peter_d_sherman 3y ago
  >Scope with 8-bit resolution is a logic analyzer with delusions of grandeur. The scope of this article/project (pardon the pun!) -- was to make a an actual scope -- that is, an oscilloscope and an oscilloscope only(!) NOT a full blown logic analyzer! A logic analyzer, for those who do not know what the difference is, is sort of a "deluxe" scope, with additional high end "luxury" and extended features and capabilities that are typically limited or not available on a simple oscilloscope... You have oscilloscopes on the one hand, logic analyzers on the other... Just like you have Volkswagen Beetles on the one hand, Ferraris on the other. Or, Priuses on the one hand, and Teslas on the other... Bicycles and other simple transportation devices on the one hand, Cars, Trains, Planes and other much more elaborate transportation devices -- on the other... So yes, I agree with the generalized statement: "Scope with 8-bit resolution is a logic analyzer with delusions of grandeur." But we are NOT trying to build a full-blown, full-featured costly and expensive logic analyzer here... No, we are only simply trying to build a simple oscilloscope... Now, don't get me wrong, your comments are certainly valuable, and all of them are apropos for the building and construction of high-end logic analyzers... And, I'm sure that anyone who would design a logic analyzer or put themselves to designing one now or in the future -- would greatly appreciate them! But (and I'm sure you'll pardon the pun!) -- a full-blown logic analyzer -- is a little bit out of the -- scope -- (the oscilloscope that is!) -- of this project! <g> :-) <g>

pjc50 3y ago

> 8-bit microcontroller Scope with 8-bit resolution is a logic analyzer with delusions of grandeur. 16 bits is realistically the useful minimum; if you want to do scaling in digital rather than the analogue front-end, you'll want 24 which is significantly more expensive. So you want at the very least a 16-bit microcontroller and in practice just an ARM. Next question is what you want to do about capture rate. 20MHz would be nice, the standard for thirty year old CRT scopes, but realistically audio frequency or 1MHz is going to be about the most you can do. TBH, something that can capture I2C and SPI and audio frequency does actually cover some useful use cases. Might be fun to give it a 3.5mm stereo jack for the probes or direct audio input. > some circuitry to block excessive currents The scope is high-impedance so this shouldn't normally be a problem. (You're not going to have a 50 ohm BNC input on a watch). You might want to think about voltage, but the sort of person who decides they want to look at the mains frequency cycle on a device strapped to their wrist won't be deterred by warning stickers.

planede 3y ago
8-bit micros can and usually have wider than 8-bit ADCs. Having said that you are right, I don't expect this ADC to work as a decent oscilloscope.
ben_w 3y ago
> You might want to think about voltage, but the sort of person who decides they want to look at the mains frequency cycle on a device strapped to their wrist won't be deterred by warning stickers. You've just reminded me that when I got an oscilloscope to play around with, I found out — by accident and to my surprise — that my body was coupled to the mains frequency strongly enough to see it clearly just by touching the probe.
peter_d_sherman 3y ago
>Scope with 8-bit resolution is a logic analyzer with delusions of grandeur. The scope of this article/project (pardon the pun!) -- was to make a an actual scope -- that is, an oscilloscope and an oscilloscope only(!) NOT a full blown logic analyzer! A logic analyzer, for those who do not know what the difference is, is sort of a "deluxe" scope, with additional high end "luxury" and extended features and capabilities that are typically limited or not available on a simple oscilloscope... You have oscilloscopes on the one hand, logic analyzers on the other... Just like you have Volkswagen Beetles on the one hand, Ferraris on the other. Or, Priuses on the one hand, and Teslas on the other... Bicycles and other simple transportation devices on the one hand, Cars, Trains, Planes and other much more elaborate transportation devices -- on the other... So yes, I agree with the generalized statement: "Scope with 8-bit resolution is a logic analyzer with delusions of grandeur." But we are NOT trying to build a full-blown, full-featured costly and expensive logic analyzer here... No, we are only simply trying to build a simple oscilloscope... Now, don't get me wrong, your comments are certainly valuable, and all of them are apropos for the building and construction of high-end logic analyzers... And, I'm sure that anyone who would design a logic analyzer or put themselves to designing one now or in the future -- would greatly appreciate them! But (and I'm sure you'll pardon the pun!) -- a full-blown logic analyzer -- is a little bit out of the -- scope -- (the oscilloscope that is!) -- of this project! <g> :-) <g>