USB oscilloscope advice

[Jmh474]

Good morning all, my first post just joined the forum.

I'll tell you a little bit about myself first, so I trained to be an electrician about 15 years ago and worked in the trade for about 10 then started repairing electronics, iv never owned a scope before as never had the money, and yes I know I should of had one years ago, so if had to pack that up now as myself and my partner both care for our son as he has special needs, so money can be tight at times.

Iv been looking at USB scopes as there a lot cheaper compared to bench top scopes iv tried searching online for used cheap scopes and I dont think it's going to happen.
As there all pick up, I dont think it would be classed as essential travel even tho it would be to me lol

The scope in question is made buy a Chinese company called Loto, there are two versions I'm looking at are osca02 and the osc2002, I was just wondering if anyone has anything to do with these before

I'm only doing hobby work like playing around with arduino and raspberry pi,
But I am building a cnc router using a AKZ250 board.

I have tried to save a few time for one but everytime I get some money put together the house end up needing something, and my partner seems to think a new fridge is more important than a oscilloscope.

[Fungus]

Iv been looking at USB scopes as there a lot cheaper compared to bench top scopes

The general feeling around here is, "You'll get what you pay for!" and anything under about $250 is going to be a disappointment in the long term.

I'm only doing hobby work like playing around with arduino and raspberry pi,

Being able to see anything at all is better than being blind. You could get a DSO138:

https://www.ebay.com/sch/i.html?_nkw=dso138

Yes, they're a toy compared to the real thing but they're only $20 and you'll be able to see the state of Arduino pins using one. It's a start. 

[drussell]

Iv been looking at USB scopes as there a lot cheaper compared to bench top scopes iv tried searching online for used cheap scopes and I dont think it's going to happen.

I'm not sure what your budget is, but if you can't afford one of the entry level Pico scopes, perhaps consider the 25 MS/sec Velleman PCSGU250 as an option, since it is about half the price of a Pico.  I have never used the PCSGU250 model myself, but I built a K7103 kit (parallel port interface, 32 MS/sec, single channel upgradeable to dual with the K7104 kit) back in the mid '90s and it has served me well for many years.

At $70 USD / $90 CAD it seems like it might be a potential candidate for your needs as a starter scope, although I'm not sure about more local, UK pricing and availability.

[tunk]

For about the same money you could get a Hantek 2C42, or a bit
more, the Fnirsi 1013D (real bandwidth 20-30MHz). Between these
and the DSO138, you have the Dso Pro (~40us$, 2-3Mhz bandwidth)
and several 20-30MHz at around 70us$ (claimed bandwidth 100MHz).

[Gyro]

Welcome to the forum.

As others have said, you need to be very careful at this price point with USB scopes. Work out your exact budget and use as much of it as possible. It's not worth going below your budget for a 'cheap' one.

Stay away from 'toys' for now because they are only single channel. Yes, they are useful toys, but they're a nice to have if you already have a scope.  Things like the DSO138, or better, the DSO150 (better UI) fall into this category. They also need power, even if it's just a strapped-on battery pack. One of the main functions of a scope is to be able to compare the relationship of different signals [Edit: and you can't do that with 1 channel].

I think I've seen the scope you show listed previously under the Sainsmart brand, however they tend to buy up stuff and badge it. You need to be really careful of the specs. Ignore the 1Gsps equivalent sampling time spec and concentrate on the real time sample rate. I've looked at the datasheet and I still can't work out whether the 200Msps is per channel or shared between the two. The other things I noticed on a brief scan is only 6 vertical sensitivity ranges, the horizontal timebase stops at 2s/div, and importantly, only edge triggering.

Ultimately it depends on how the H/W and software/UI work together, if nobody here has direct experience then you're down to searching out Youtube reviews.

As mentioned above, work out your budget. Integrated Logic analyser cuts your options, you might as well pick up one of the 'pocket money' £10 8 bit Saleae clones and use it with Sigrok (plenty of search references) to get started with an LA.

There are long threads with detailed reviews of things like the Owon VDS1022(I) and Hantek 6022 family scopes on here. Both have their limitations (particularly the Hantek H/W) but these are well documented and both have PC S/W improvements written by enterprising folks.

I have no knowledge of the Hantek 2C42 or the Fnirsi, but there are folks on here that own them and do.

Unfortunately Chinese stuff isn't as cheap on ebay as it was a year or so back, but there are sellers with UK stock.

[rstofer]

Just for giggles, I bought one of the DSO150s.  It is just a single channel, bandwidth isn't all that high (250 kHz) but it provides a lot of on-screen measurements and some of the features you expect in a DSO.  The interface takes some getting used to but it's only 3 buttons and an encoder with a push button.

Less than $30 and it actually puts a trace on the screen.

I'm not recommending, I'm just saying I bought one.  It won't replace my DS1054Z or my Tek 485 any time soon.

https://www.aliexpress.com/w/wholesale-dso150.html

Maybe it's a start...

BTW, the battery (if you plan to use a battery) doesn't mount in the case, it dangles on the bench and mine didn't come with the battery cord or a wall wart:

https://www.amazon.com/gp/product/B07NV772WM

Pay attention to the advertisement, it clearly calls out that the wall wart is optional.

GOTCHA:  The PS connector is center pin positive.  My first search at AliExpress turned up wall warts with center pin negative.  The battery clips I linked are center pin positive.

[Gyro]

Sorry, a quick OT just for @rstoffer. You can actually squeeze a Lipo cell inside with appropriate charger and boost converter. It's fiddly but doable and makes a world of difference... https://jyetech.com/forum/viewtopic.php?f=19&t=1153&sid=97a5386cee6a8b15127893473b01dc35

[GerritMax]

Good morning all, my first post just joined the forum.

I'll tell you a little bit about myself first, so I trained to be an electrician about 15 years ago and worked in the trade for about 10 then started repairing electronics, iv never owned a scope before as never had the money, and yes I know I should of had one years ago, so if had to pack that up now as myself and my partner both care for our son as he has special needs, so money can be tight at times.

Iv been looking at USB scopes as there a lot cheaper compared to bench top scopes iv tried searching online for used cheap scopes and I dont think it's going to happen.
As there all pick up, I dont think it would be classed as essential travel even tho it would be to me lol

The scope in question is made buy a Chinese company called Loto, there are two versions I'm looking at are osca02 and the osc2002, I was just wondering if anyone has anything to do with these before

I'm only doing hobby work like playing around with arduino and raspberry pi,
But I am building a cnc router using a AKZ250 board.

I have tried to save a few time for one but everytime I get some money put together the house end up needing something, and my partner seems to think a new fridge is more important than a oscilloscope.

Depending where you are in the UK I'd say look on facebook as there are actually a few up for sale
for not even that much money https://www.facebook.com/marketplace/108451039178633/search/?query=oscilloscope.

[Simon]

If you want USB look at picoscope. I have the very base model, yes i can see it's bandwidth limitations but it's great for fiddling with anything on the desk that it will cope with if exact measurements are not needed. the 10MHz and 25MHz are as far as I would spend money on a USB scope though.

For some reason USB scopes always end up costing more than a standalone one which gives you far more more bang per buck than USB. We have a pico scope at work because I can save the setup and then people in quality department can just launch the program with the setup I saved and follow instructions. But if I am called to help I just bring over my Rigol as it's so much easier to use and more powerful.

[rstofer]

Sorry, a quick OT just for @rstoffer. You can actually squeeze a Lipo cell inside with appropriate charger and boost converter. It's fiddly but doable and makes a world of difference... https://jyetech.com/forum/viewtopic.php?f=19&t=1153&sid=97a5386cee6a8b15127893473b01dc35

Thanks!

[2N3055]

For some reason USB scopes always end up costing more than a standalone one which gives you far more more bang per buck than USB. We have a pico scope at work because I can save the setup and then people in quality department can just launch the program with the setup I saved and follow instructions. But if I am called to help I just bring over my Rigol as it's so much easier to use and more powerful.

I respectfully disagree. Picoscopes are much more powerful than most standalone scopes costing much more. Out of the box, for free they decode 23 protocols at the moment (and they keep adding them), they have unlimited math, custom probes with transfer function definition, large memories, good API, good FFT, DeepMeasure, etc. Find a scope that you can look at with 2x27" screen having 16 different views open at the same time.....
For in depth analysis of signals, very good tool. It has it's own drawbacks, but very useful.

Of course, that is important (and worth the money) only if you plan to use all that. If you use scope in classic manner all of that might not be needed and no need to pay for capability you won't use...

[Simon]

My comparison is more at the entry level. If you take a 2000 series it quickly gets expensive for what I think are similar specs to a standalone Rigol. Yes if you go into the higher ranges they may well be better bang per buck but at the entry level being talked about it's more about the portability etc than cost per performance.

[rstofer]

A Pico Scope 2408B 4-channel 100 MHz is roughly equivalent to the Rigol DS0154Z and costs $1125 versus $349 for the Rigol.  For some notion of equivalence...

There are lesser models but since the Rigol is considered the defacto entry level scope, the Pico selection should be roughly equivalent.

Yes, the Pico has some software defined tools that are really useful but at 3X the price, maybe I would rather have a bench scope.  I can still do screen capture and print the results.

I can't argue against a  27" screen, that's how I run my Analog Discovery 2.

[Simon]

i like my 10MHz picoscope and wish I had got the 25MHz but after that it's pricy. I noticed a correlation between the price and the sample memory, this seems to be the price driver.

[2N3055]

A Pico Scope 2408B 4-channel 100 MHz is roughly equivalent to the Rigol DS0154Z and costs $1125 versus $349 for the Rigol.  For some notion of equivalence...

There are lesser models but since the Rigol is considered the defacto entry level scope, the Pico selection should be roughly equivalent.

Yes, the Pico has some software defined tools that are really useful but at 3X the price, maybe I would rather have a bench scope.  I can still do screen capture and print the results.

I can't argue against a  27" screen, that's how I run my Analog Discovery 2.

As I said analysis tools are worth the price, if you need them, that is..

23 protocols, unlimited math etc etc... PC API that works...

If you don't need that, standalone scope can be had for less.

[Simon]

I'm going to guess that a fair part of the price is the PC software and the bells and whistles. I see a contractor we use has a £1'000 USB spectrum analyser, I don't know how much they are otherwise but it seems pretty cheap for a good bit of kit. I suppose it's breaking the £500 point that the price starts to take off and specs diverge to the point of becoming specific beasts.

[Fungus]

23 protocols, unlimited math etc etc... PC API that works...

Sigrok has 130 protocols and it works with a $7 USB logic analyzer.

https://sigrok.org/wiki/Protocol_decoders

https://www.ebay.com/sch/i.html?_nkw=USB+logic+analyzer+24m

[Syntax Error]

If you're interested in seeing what the Picoscope range can acheive, you can download the latest PicoScope software [6.14] for your platform (Windows, Mac, Linux) and play with the features in real time, using the inbuilt function generator in it's 'demo mode'.

https://www.picotech.com/downloads - select Picoscope 2000 series + 2204A/2205A

Even the entry level 2204A (two input, one AWG output) is a solid and reliable piece of test equipment that's no toy.

https://www.picotech.com/oscilloscope/2000/picoscope-2000-overview

[2N3055]

23 protocols, unlimited math etc etc... PC API that works...

Sigrok has 130 protocols and it works with a $7 USB logic analyzer.

https://sigrok.org/wiki/Protocol_decoders

https://www.ebay.com/sch/i.html?_nkw=USB+logic+analyzer+24m

Yep, nice try buddy.. Not even close..

Sigrok is amazing for free. But not a pro tool.

And we had that discussion many times before. Cheap LA is not replacement for mixed signal debug with scope.

Cheap LA and Sigrok are GREAT for troubleshooting software side of protocols though. Once you know signals are right in analog domain.

Benefit of Pico (or some other deep mem mix. signal scope) is that you can look at things simultaneously.
That is something useful with CAN bus for instance, where software error in one node can manifest itself with level errors on the bus.
That can be seen only with scope in analog domain.  So you search for packets with error, and you zoom in to that one and see problem with level because some other node injected disturbance in bus....

[rsjsouza]

Ok, ok... Bringing back from the flame wars of USB oscilloscopes to the main topic.

I also have the Owon VDS1022I mentioned by Gyro above and it is a fine piece of instrument. For a USB model, you have to always take into consideration the software stability and bugs, and the Owon does not disappoint in this front.

I personally don't know the Hantek or the Loto mentioned by you, but at least the Hantek brand is famous for cutting corners in its Hardware.

The designer of the Loto oscilloscope is active in a thread here in the EEV: https://www.eevblog.com/forum/testgear/how-to-promote-an-usb-oscilloscope-to-individual-engineers-i-am-the-loto-instru/msg3452262/#msg3452262

I also see you are using the AKZ250 board, which has servo control of up to 200kHz - the oscilloscopes of 10MHz and above are enough to see the waveforms at that frequency.

[Jmh474]

Well thanks for all the information it's very appreciated,
I guess my budget is around £100, I can guess a lot of you will sit back and laugh, and I can understand why, I know it's a case of you get what you pay for with this type of equipment.

One of the main reasons for the purchase is so I can check pwm for any noise, and this will help in cleaning it up.

I have tried looking on Facebook in my area (Cambridgeshire) but sadly at the moment the closest I can find is like 50 miles away, iv already been pulled a few times already, one when going shopping and another when I took my son for a drive as it helps him with meltdowns.

I am thinking of trying to put off buying one at the moment and hope something might pop up but as I'm sure you all know nothing ever turns up until it's to late

I've googled and YouTube the scope and from what I can tell it's not to bad a scope they've put a lot of time into the software from what I can tell, it's also open source they offer open source module pcb.

Again that's for the advice, but for now the hunt goes on

Just trying to find best bang for the buck

[Syntax Error]

@Jmh474

Just to let you know, Pico Technology is in St.Neots Cambridgeshire, so if you go this route (basic model 2204A ~£100), you'll be supporting a local company. Happy hunting 

https://www.picotech.com/about/uk-address

[Simon]

I have the 2204A, it's good, obviously only 10MHz which means sine wave at 10MHz so 1MHz square. I have been able to get an AVR µC pin to toggle fast enough to not be properly represented so you have to be careful to not let yourself be fooled. If you want to.

It's ideal for looking at PWM outputs of a µC as 20MHz/256 = 78kHz, even if your counter is counting up to 100 it's 200kHz which is not too bad.

[Gyro]

I guess my budget is around £100, I can guess a lot of you will sit back and laugh, and I can understand why, I know it's a case of you get what you pay for with this type of equipment.

Not at all, there are many of us who can't justify spending more that we do on test equipment. It's developing the skills to get the best use out of what you have that counts. 

P.S. When every penny counts, you might need to sacrifice your buying principles a little.  Eg. You can get more than 10MHz bandwidth for £100.

[2N3055]

Well thanks for all the information it's very appreciated,
I guess my budget is around £100, I can guess a lot of you will sit back and laugh...

Absolutely not.. I remember it all too well...
Owon mentioned by Gyro and Rjsouza is very useful instrument I wish I had not so many years ago....

Just keep going... Don't let anything or anybody discourage you...