Who doesn't want a scope on their wrist?

[parabuzzle]

I just saw this in my social network and got a bit giddy about the idea of a basic scope on my wrist...
 
A kickstarter for a scope watch with generator and more.. really?

http://www.kickstarter.com/projects/920064946/oscilloscope-watch?ref=card

[Bored@Work]

That rubbish was already previously discussed here.

[nitro2k01]

As always, the challenge is making it not suck. The analog front end is always going to be very basic with this kind of thing. How do you add connectors for some kind of probe that is going to be durable. In the end of the day I think the real use for a watch like that is going to be showing off to your friends that you have portable device that can pick up mains hum from the air.

[sync]

I don't want a scope on my wrist!
I don't want accidentally put a high voltage on my left arm.
Very stupid and dangerous idea.

[grumpydoc]

I don't want a scope on my wrist!
I don't want accidentally put a high voltage on my left arm.
Very stupid and dangerous idea.

It's probably just as well it only does -14V/+20V

But at 4Ms/s, it's not going to be much of an oscilloscope.

It's a gimmick but appears to be a (mostly) harmless one.

[free_electron]

 

[Mechatrommer]

I don't want a scope on my wrist!
I don't want accidentally put a high voltage on my left arm.
Very stupid and dangerous idea.

either dont use it for mains or.... a fully rubberized unit will be a good idea something like this (this is the closest i can google )...

[mikeselectricstuff]

Forget the analogue performance, battery life and display, the UI will be impossible to do anything useful with. 

[johnnyfp]

They should make it CatIV rated. Honest it won't hurt a bit when you test it out.

[EEVblog]

As much as I like both watches and scopes, the whole concept of being any sort of usable product is just a complete fail, for so many reasons.
It makes a great Hack-A-Day article, but that's where it should have stopped.

[parabuzzle]

I must admit my subject for this was a bit tongue-in-cheek troll bait 

I totally agree this is a total gimmick that I think is essentially useless in a real lab. I originally saw this on a synth forum that I frequent and I could see a small use for sound designers (such as myself) if the menus didn't look so horrendous to navigate. It looks like a nightmare to try and navigate that thing.

I also think this should never go beyond a fun DIY build project kit. I would think that if you are skilled enough to build it yourself you should know the dangers of checking out the 60hz mains cycle with the thing. A mass production model of this that anybody can just buy scares the **** out of me. Just ref EEVblog #279 "How not to blow up your oscilliscope" ()

-mike

[ivan747]

Oh god, the schematic looks more like a puzzle than a schematic 

http://www.gabotronics.com/download/xproto-watch/xprotowatch-schematics.pdf

[parabuzzle]

It doesn't look that scary but the fact that he puts in a watch is pretty amazing any way you look at it

[free_electron]

Oh god, the schematic looks more like a puzzle than a schematic 

http://www.gabotronics.com/download/xproto-watch/xprotowatch-schematics.pdf

[VOMIT ICON] another one of those 'let's cram it all one one page' schematics [/VOMIT ICON]

[parabuzzle]

Yea, that schematic should have been a few pages...

[AG6QR]

It occurs to me that I run across the random need for a volt/ohm/continuity meter far more often than I need a scope.  And unlike a scope, a meter's display could still be reasonably readable if shrunk to the size of a watch.  And a meter doesn't need as many controls.

Still, there's no way I'd buy a wrist multimeter.

The issue of probes alone is enough to sink either a scope or a meter for me, even without other issues.  And there are plenty of other issues, especially for the scope.  Safety, control UI, battery life, and display size are a few that come to mind immediately.

[c4757p]

Oh god, the schematic looks more like a puzzle than a schematic 

http://www.gabotronics.com/download/xproto-watch/xprotowatch-schematics.pdf

This causes me actual, physical pain.

I think I'm most confused by why the hell they have the AVR block diagram inside U1. It's not like it lines up with the pins or anything, what's the damn point? And they clearly don't know how to label things properly. They've gone around and farted power consumption figures onto (some of) the parts - can't power budgeting stay in a spreadsheet?? - but as for things that really matter, like "what voltage is VDD", you have to go look up the datasheet for the regulator and compute yourself based on their set resistor...

And they have 15pF caps on the inputs! First of all, it's not like they're going to get any bandwidth where the input capacitance really matters with a TL064 as the frontend amplifier... but 15pF is a typical figure for the total input capacitance! That's going to be added on top of any stray capacitance they have... they ought to build it, measure the capacitance, then add enough to get to 15pF.

[perfect_disturbance]

I think this is a clever idea. Will it be usable as a scope, no. Safe to use on high voltage, no probably not. an interesting conversation piece? Yes. The real problem is the price. Over100 dollars for a conversation piece is kinda hard to swallow.

[PlainName]

like "what voltage is VDD"

Doesn't the "+5V" terminal label give a slight clue?

[PlainName]

like "what voltage is VDD"

Doesn't the "+5V" terminal label give a slight clue?

No, that's a separate thing. Duh! 

[Stonent]

There are some times that I would have liked to probe a waveform on a car, but I think I might go with one of those throwaway MP3 player based scopes for that.

[tom66]

I could actually see a lot of use in a scope the size of a mobile phone which had reasonable specs, say: 25MHz bandwidth 250MSa/s and at least 1Mpt of memory.

So many times I am working on for example a big plasma TV and having to move my scope from my bench all the time is inconvenient, or which might be otherwise occupied.

Digital phosphor type display would also be very useful, advanced triggers are a necessity as is a clearly readable, large screen (at least 3.5" 320x240 pixel.)

If you are going to put a DDS on the scope, you can get DDS generator chips. They would give you 50 MHz+ output frequency with a decent filter. Why bother with such a rubbish 53kHz bandwidth? It's useful to be able to inject a square wave into a circuit to see how the circuit responds, but limiting yourself to that low frequency doesn't make for a useful tool.

[ivan747]

There are some times that I would have liked to probe a wave form on a car, but I think I might go with one of those throwaway MP3 player based scopes for that.

One of those Velleman HPS40 could do the trick and they are more robust. Mike has done a couple of videos on them, but no review. I think he can advise you further. I had an HPS10, extremely basic but still better than the DSO nanos as it had real AD and DC coupling, BNC input and a sturdy case. I picture it surviving the electronic hell automotive electronics much better than a modified MP3 player. Also the parts seem easier to replace, at least on the HPS10: the LCD is a module, the PIC is on a socket (you will never get firmware though), everything is SOIC and other large SMDs or PTH.

[ivan747]

If you are going to put a DDS on the scope, you can get DDS generator chips. They would give you 50 MHz+ output frequency with a decent filter. Why bother with such a rubbish 53kHz bandwidth? It's useful to be able to inject a square wave into a circuit to see how the circuit responds, but limiting yourself to that low frequency doesn't make for a useful tool.

Velleman has been making handheld signal generators, just like their handheld scopes, they are too basic. 2MHz bandwidth at most, and I think that's only for square waves. 

I guess we should stick to Hantek handheld scopes and used Fluke ScopeMeters for our portable needs for the moment.

[ganzziani]

but as for things that really matter, like "what voltage is VDD"

The regulator can output either 1.8V or 3.0V, that is why I just show VDD.

they ought to build it, measure the capacitance, then add enough to get to 15pF.

I will check into this.

I accept and encourage criticism, but saying that the device is just a crappy scope isn't fair. The scope is just one of many modes of the device.
I understand that with today's scopes specs in the GS/s, something like 4 MS/s is less appealing, but it is still useful for many applications.

The device is also a protocol sniffer for I2C, SPI, and UART; it can sample digital data at 16MS/s; it can measure frequency on digital signals up to 16MHz; it has an Arbitrary waveform generator; it can generate component curve traces by using the AWG along with the scope.; it can connect to a tablet or computer. All this in a device that weighs about 30grams. Even if you don't use it as a watch, it can be a useful tool that you can leave on your toolbox without taking much space.

I just made a new video today, check it out if you are interested: