Handheld Oscilloscopes, DSO Nano V3

First let me state my only need for an oscilloscope is in the realm of digital logic, and for that purpose this unit exceeded my expectations, especially at its price point. While it would have been nice if the unit had more than one channel, I'm quite sure that would have upped the price and my needs are pretty much taken care of by a single channel. I used the unit as configured out of the box with no difficulty, so had no reason to upgrade its firmware. As others have noted, the documentation could use a good rewrite (the Wiki on the http:slash slash: wiki.seeed.cc slash DSO_Nano_v3 slash web site is far more useful). In any event what really got me off the ground with the interface was simply using the unit's square wave generator to provide input to the device. The supplied probes are well suited for that purpose since you can plug one into the square wave generator and the other into the channel input. Since one probe has wire clips and the other bread board plugs, it's a simple matter to connect one to the other. What should come up on the display (with the unit USB powered) is a 5V, 1KHz square wave with a 50% duty cycle. From there you can play with the menu buttons to manipulate the screen, check measurements, etc. There are (physical) A and B buttons on the side that I didn't find necessary for my use (the Wiki indicates they are for "run/stop" and "quick adjust" where the A button will freeze the display until pressed again and the B button serves as a shift button for quick functions). An Allen wrench is supplied for removing the back cover of the unit if necessary for calibration (assuming one has calibration equipment). The V3 has internal memory for saving data in various formats (including as an image) rather than an SDI card slot (the Wiki has that wrong).My first use for the device was resolving an issue with an implementation using a 555 timer chip that was not behaving as expected. It took me less than 5 minutes using this device to locate and correct the problem. Further exploration enabled me to take a look at a capacitor's charge/discharge cycle. Things like frequency, duty cycle, and peak voltage also proved easy to acquire by using the (white) Measure menu item to select the value to display. The display is a tad awkward, but easy enough to use once you figure out that the upper up/down arrows select a menu item, the OK button allows you to configure the menu item, and the lower up/down buttons allow you to adjust the value on the top line whose color matches the menu item's color.One other factoid I had to ferret out from the rather cryptic manual entry regarding it, to retain a setting (e.g., to have the device start with Data turned OFF), simply navigate to the menu item, put in the desired setting, press and hold the A button until the message comes up about retaining the setting, then release and press the A button again to retain the setting.I don't think I would use this for professional work, but for a quick reality check and circuit debugging it is excellent. The supplied probes are more than adequate for that purpose. Given its price point, I think a 5 star rating is appropriate.Addendum: there seems to be confusion in other reviews regarding the probes. The supplied probes are x1 probes, with a limit of 80Vpp, or ±40V. I think they are pretty good for digital work, since one set has bread board points and the other has hook clamps, good for attaching to component wires. If you obtain a x10 probe, the probe will handle up to ±400V. x10 probes will probably have a BNC plug, so an adapter is needed. If you need a x10 probe, a cheap option from Amazon (all for < $20) is  Sumnacon® 2 Pack P6100 100 MHz 600V DC High Sensitivity Oscilloscope Clip Probe 10:1 and 1:1 Switchable with Mini Alligator Clip and Ground Lead for Rigol Atten Owon Siglent,HP Tektronix,RIO DSO, Hitachi,GwInstek  along with the adapter  kenable BNC Socket to Composite 3.5mm Male Jack Plug Adapter GOLD .

Don't buy this with the "Frequently Bought Together" power supply:Wall Adapter Power Supply - 9V DC 650mA https://www.amazon.com/dp/B003XZSZWO/ref=cm_sw_r_sms_c_api_zW3GybRJA2J2YIt doesn't even fit the Oscilloscope

I bought this for troubleshooting a PWM signal on a commercial boiler. The unit is small, easy to use (once you get accustomed to the way the menu works) and a great value!One thing I didn't care for was the fact that there is something "rattling around" inside. It's like they didn't secure the internals.Good little unit for the $$ otherwise!

I'll make it (somewhat) short and simple:I don't know what some of these reviewers are talking about, as this little thing is very, very cool. It's very solidly built - with a metal case, and it looks and feels like quality construction. I had it showing me some Arduino pulse width modulation RIGHT OUT OF THE BOX - no updates, no setting up, I didn't even take the time to remove the screen-protecting plastic, just UNPACK AND GO!.The screen is bright and crisp, the menu functions are easy to navigate. I won't even say "for the price"... I'll say only "this thing is incredible... PERIOD."I guess a few reviewers just didn't read the description before purchasing? Of course it's small - that's why it's called a "nano" oscilloscope. It is exactly what I was looking for, and expecting.For us tinkerers and thinkerers, it's perfect addition to our toolbox, or in my case, my coffee table. I highly recommend it for people like us.*** UPDATE: It's still awesome.

I was looking for a cheap oscilloscope to look at synth / eurorack output, and this thing absolutely delivers - i've used it to calibrate several modules already as well as just look at the output and see what's going on in general. It's helped me spot some things I was doing dumb as well, like accidentally adding a DC offset that wasn't directly audible.This thing really has its limitations, and won't remotely compare with a "real" oscilloscope, but it's more than good enough for anything I'm doing in the synth world, and will probably be great for any other hobbyist use as well.Highly recommended.

there are no instructions & those on internet have buttons/functions not described on this unit.

I have to say I did not know what to expect. I found this lil unit to be completely intuitive and easy to use. It was extremely accurate in gain leveling my amplifiers to give them 0 distortion. It is very well constructed and has a very nice fit and finish. I highly recommend it to anyone needing an oscilloscope but it is inconvenient taking a big unit out in the field.

Excellent little scope. As a note, "Mini" usb cable/charger is NOT included. Most phones/etc use "Micro" usb, not "Mini" usb. You should make sure you have a "Mini" usb cable/charger on hand, or order one when you order this - otherwise you won't be able to charge it.As for the 'Scope, it's awesome. It does exactly what I need it to. It took a little poking to figure out the interface, but now it makes sense.As a suggestion, you should also order a 1:10 probe when you order this.

Great product - very nicely put together.