Aeroscope Wireless Oscilloscope Probe

[el_dooderino]

Hello,

I am one of the creators of Aeroscope, a BTLE connected oscilloscope. Aeroscope pairs to your iPhone or iPad (Android and Windows coming soon) so you can easily make measurements in the field. It is small enough that it can be embedded inside of mobile electronics like robots or drones, allowing users to measure signals in the field while their system is underway. Our goal is to enable users to have a scope with them whenever and wherever they are, just throw it in your shirt pocket and you are ready to go. I'd love to hear any feedback that you eevbloggers have about Aeroscope.

https://www.crowdsupply.com/aeroscope-labs/aeroscope-wireless-oscilloscope

Thanks!

[PA0PBZ]

First thought: Like 

After seeing the video: Really? showing a tube amp and a large solar array with a +/- 40V input?

[el_dooderino]

There is a little bit of marketing spin in the video. However, Aeroscope does have a 1M || 17 pF input and can be used with external 10x probes to expand the input voltage range.

[PA0PBZ]

There is a little bit of marketing spin in the video.

Of course, it's a marketing video after all

However, Aeroscope does have a 1M || 17 pF input and can be used with external 10x probes to expand the input voltage range.

External probe with I guess SMA? The question then is, is it still a wireless probe? 

[el_dooderino]

Ha. Good question. Well, at that point it is still isolated so, mostly wireless. 

[janoc]

When I saw "wireless oscilloscope probe" and "crowd funded" my immediate reaction was - "Oh not another crappy toy".

However, this seems to have actually useful specs. 

The only thing I would recommend is changing the color palette in the app - red text on red background? Come on, make the labels easy to read with some contrasting colors. You are using a full color screen, not an ancient monochrome CRT. Don't spoil a potentially decent product with crappy software/user interface.

[el_dooderino]

Hi Janoc

Thanks for the support! Regarding the app color palette, I think that the pics on the Crowd Supply page make it look a little harder to see than it actually is. We are planning on offering an option to switch to "day time mode". This will be a higher contrast color palette that will be easier to see in full sunlight.

[janoc]

Hi Janoc

Thanks for the support! Regarding the app color palette, I think that the pics on the Crowd Supply page make it look a little harder to see than it actually is. We are planning on offering an option to switch to "day time mode". This will be a higher contrast color palette that will be easier to see in full sunlight.

I don't see why there should even anything else but a "day time mode" palette - are you using a scope in the dark? I guess most people are not - they like to actually see what they are measuring. If you want to keep that low contrast "red-on-red" one for whatever reason, at least don't make it the default.

Engineers are conservative beasts - if I was you I would try to emulate the look and feel of a normal scope, because that is what most people are used to.

Another tip would be to sell the device with a an SMA-BNC adapter and a regular 10x or even 100x probe, perhaps as a bundle.That would let people who want to exploit the isolation of the device and work on mains powered stuff, like power supplies, have everything together and ready to go.

An even better thing would be to add that 10x divider to the built-in probe, though - a 1x probe is rarely useful due to the input capacitance loading down the DUT.

Oh and that tube guitar stomp or what is that thing in the video - that foot right next to the exposed glass of the
tube is seriously cringe-worthy. Did nobody stomp on that tube instead of the button next to it yet?

[David Hess]

With no probe cable the input capacitance of 17pF with a 1 megohm input resistance is not a problem at 20 MHz so it does not need a 10x divider except to increase the input voltage range which admittedly is a problem.  This galvanically isolated oscilloscope would be more useful if it could make line side measurements which implies an input voltage range extending to 50 volts/division.

The bit resolution is not in the specifications.  Further it is not clear how the input range switching works.  With bench oscilloscopes it can be assumed that every range is switched and the full resolution applies to each range but there are plenty of cheap DSOs which do not do this relying instead on "software magnification" and do not specify it because it would make them look bad and doing the same thing here makes this product look similarly bad.

What is the input overload range?  What is the transition time?

I hate both primary and secondary lithium batteries in test equipment.  Is it user replaceable?

[MagicSmoker]

Aww, criminy... I think this is an ingenious idea - probably because I was contemplating designing something very similar except for relative current measurements using a partially-shield Hall effect sensor (feel free to steal the idea), until I saw that the input is limited to +/-40V!?! Perhaps a stretch goal for a higher priced version that either has a x10 switch or reduced sensitivity across the board (ie - 1V to 100V/division)?

Otherwise all the other design choices look pretty good, especially for the price.

[el_dooderino]

Hi David

Thanks for pointing out that we are missing the bit resolution on the Crowd Supply page, we'll add that to the page right away. You can find a more complete datasheet here:

http://www.aeroscope.io/s/Aeroscope100A_SpecSheet.pdf

The ADC resolution is 8 bits, and each voltage setting utilizes the full ADC range. We aren't doing any "software magnification" mumbo jumbo.

Our input overload spec is +/- 48 Vdc but we have tested the product up to 120 Vdc without seeing any issue. We also have protection circuitry to deal with ESD events.

By transition time do you mean rise time? I've attached a picture of an edge showing a rise time of roughly 17.5 ns which is what you would expect from a 20 MHz bandwidth.

The battery isn't user replaceable but we are planning on offering reasonably priced replacement if you notice your battery's performance has degraded.

Thanks!

[el_dooderino]

Thanks for the feedback magic smoker. As I mentioned before, you can use an external probe to increase the input voltage range.

[Kean]

This looks pretty good, but not something I need as I already have a Saleae Logic Pro 8 and multiple bench scopes.

I would say though that the choice of red text on a darker red background for the menus is terrible.  Even the red text on grey background provides quite poor readability.

[David Hess]

The ADC resolution is 8 bits, and each voltage setting utilizes the full ADC range. We aren't doing any "software magnification" mumbo jumbo.

I would sure include that in at least the detailed specifications.

Our input overload spec is +/- 48 Vdc but we have tested the product up to 120 Vdc without seeing any issue. We also have protection circuitry to deal with ESD events.

Most oscilloscope high impedance inputs can handle about a continuous 400 volt peak overload (1) so a direct connection to the 340 volts present inside of an off-line switching power supply is not destructive.  Having a galvanically isolated battery powered oscilloscope with a Bluetooth interface and this level of overload and measurement capability would be uniquely useful for making off-line measurements safely.

Some high frequency active probes have a 1 megohm input impedance but include a 10x divider before the amplifier multiplying their input voltage range and overload capability by 10 times at the expense of noise.  I might do something similar to increase the input voltage range.  (2)

By transition time do you mean rise time? I've attached a picture of an edge showing a rise time of roughly 17.5 ns which is what you would expect from a 20 MHz bandwidth.

I mean rise or fall time but it just seems easier to say transition time to cover both.  17.5 nanoseconds is what one would expect for a 20 MHz bandwidth with a single pole roll off but this is not always the case so it is nice to see both specifications.

(1) At least all of mine do.  I know some modern DSOs do not have quite this level of overload protection.

(2) The input range and offset specifications suggest a 10x attenuation stage is already used at the input.  If so a 100x attenuation stage would be needed but that might increase noise too much for some applications.

[ebastler]

I don't see why there should even anything else but a "day time mode" palette - are you using a scope in the dark? I guess most people are not - they like to actually see what they are measuring. If you want to keep that low contrast "red-on-red" one for whatever reason, at least don't make it the default.

Finally, an oscilloscope for astronomers! 
Of course the display must be red, so your night vision does not suffer...

Seriously though -- very nice design! Best of luck with your endeavor!

[HighVoltage]

Nice design of the probe, good luck!

But I agree, your choice of screen color combinations is horrible !

[el_dooderino]

Thanks for the feedback guys!

[el_dooderino]

Hey EEVbloggers,

I wanted to update you on Aeroscope's progress. We have shipped out units to all of our crowd funding backers and are now selling Aeroscope through our website www.aeroscope.io/store. If you are looking for a low cost, ultra portable, isolated scope swing by and check out Aeroscope.

Also, one of the biggest pieces of feedback we received from this forum was to change the color theme. The app now includes 4 themes, varying from the original dark red theme to an ultra bright day light readable theme.

Thanks for the feedback!

[HighVoltage]

Also, one of the biggest pieces of feedback we received from this forum was to change the color theme. The app now includes 4 themes, varying from the original dark red theme to an ultra bright day light readable theme.

Thanks for the update!
Where are some screen shots?
On your website I only see the old color combinations.
If you want to promote it, post some pictures and screen shots here

[el_dooderino]

Good idea HighVoltage. Attached are screen shots of all the color themes.