Oscope Selection

Been looking at oscilloscopes for a while. I only have a multi-meter right now and am finding I am pretty limited in what I can do. I have read several threads on the Diligent 2 and even downloaded and installed the software. From what I have read it should do everything I need. The only thing I see myself doing right now is developing Arduino or Raspberry Pi applications. So I think this should be what i need at a price I can afford. So any suggestions. Here is what I am looking at buying.

https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/

May be ok, but without shielded test leads, it will pick up all kinds of stray signals along with what you want. If you don't look at high impedance circuits, the 1 meg input impedance will be ok.

Paul

You realize you can get more for your money. You can find 2 channel 70Mhz with probes and screen for less than that. These are pretty amazing for the money.

dso5072

There’s a lot of documentation on eevblog on how to hack it and unlock 200 MHz.

As your mostly using this for RPi/Arduino applications would most of the signals your checking be digital? I have 3 scopes that I hardly ever use but I use a logic analyser a lot more often. Something like this has both options though the pulse-view software only detects a single analogue input.

Logic analyzers are very useful also. Those little units work very well with a PC and open source software. I still recommend the oscilloscope. It’s not always digital signals you need. Power supply issues, noise, PWM, slew issues… and many other uses. With oscilloscope you need a good front end for it to work correctly without false readings. Understand how it works and how to use them so you don’t create unsafe situations as with all test equipment.

Riva: As your mostly using this for RPi/Arduino applications would most of the signals your checking be digital? I have 3 scopes that I hardly ever use but I use a logic analyser a lot more often. Something like this has both options though the pulse-view software only detects a single analogue input.

Thanks, but this only works with Windows. I run Linux on all my computers.

Hmmm,

More to this than I thought. So back to school. What is the difference between an Oscilloscope and a Logic Analyzer. I have used Oscilloscopes before (50+ years ago), so it has been a while. I guess I need to re-think this whole thing and decide what I want to really need. Right now today I am trying to analyze an optical encoder board that came from a small dc motor. No diagrams or instructions, so trying to figure the output pins as well as the power pins. My multimeter just isn't doing the job.

Thanks for all the great replies. I have more research to do I can see that.

O scope selection? Here is what I suggest you do. Sit down with a clean white blank sheet of paper. Have a nice sharp pencil and a large eraser. Start listing the features you feel, for your applications, you must have. Then move along to features you feel would be nice to have. Once you have your list then start shopping around and shopping around is important, even for the same make and model. You really want to get this down to a buy once and cry once.

Analyzing the output of an optical encoder is likely one of a few hundred applications for an oscilloscope. Logic analyzers, very briefly put, are suitable for looking at digital logic signals and normally have well over 4 channels and of low logic level amplitudes. They look at 1's and 0's. :) The oscilloscope can help you visualize analog wave forms and measure various characteristics, such as amplitude, ringing, transient signals, phase, and unwanted pulses. Even when debugging digital systems, you can easily measure signal integrity with an oscilloscope. You choose based on your applications so back to the list. This is a very abbreviated nutshell of the differences.

Ron

ov10fac: Been looking at oscilloscopes for a while. I only have a multi-meter right now and am finding I am pretty limited in what I can do. I have read several threads on the Diligent 2 and even downloaded and installed the software. From what I have read it should do everything I need. The only thing I see myself doing right now is developing Arduino or Raspberry Pi applications. So I think this should be what i need at a price I can afford. So any suggestions. Here is what I am looking at buying.

https://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/

For that money you can get a proper 'scope like a 100MHz Rigol with ten times the sample rate and decent x10 probes, well worth it if you don't need the LA function.

Many thanks, you have given me a lot to ponder and consider.

“ I have used Oscilloscopes before (50+ years ago)”

If you will be doing work with digital 5v signals, suggest you get a PC logic analyzer over a scope.

Maybe both since you are getting up in age and it’s time you treat yourself before the expiration date is met.

I don't think anyone has previously mentioned this, but the Digilent unit linked has an arbitrary waveform generation capability, that is it can generate a signal to be injected into a circuit under test. So while it is an inferior oscilloscope to similarly priced dedicated units, it does have additional capabilities.

It also apparently has a network analyzer capability, that is, the output signal is injected into a circuit and the response is analyzed via the input capture. This sort of thing is handy if one is building analog signal processing circuits, filters, amplifiers, and such. It should be fast enough to do audio up to low HF frequencies.

The Digilent also apparently has 16 channel 100 MHz logic analyzer capability.

That said, faced with the same decision in the past year, I purchased an oscilloscope model similar to the one identified in post #2, the DSO5102P.

ov10fac: Thanks, but this only works with Windows. I run Linux on all my computers.

Not according to this link.

Let me add some more for you to think about. Last Winter I sold an oscilloscope for $50 that would have fit your needs. I know a retired engineer that was almost giving scopes away because he had so many as his hobby was repairing such instruments.

Place an ad in Craig's List or on Facebook Marketplace for an oscilloscope and see if you get replies.

Paul

Riva: Not according to this link.

My bad, thank you for the correction. It downloads and runs just fine on Linux.

Paul_KD7HB: Let me add some more for you to think about. Last Winter I sold an oscilloscope for $50 that would have fit your needs. I know a retired engineer that was almost giving scopes away because he had so many as his hobby was repairing such instruments.

Place an ad in Craig's List or on Facebook Marketplace for an oscilloscope and see if you get replies.

Paul

That is a really great idea. I sell a lot of things on Craigslist but never advertised to buy something. I'll give it a try. Thanks

MrMark: I don't think anyone has previously mentioned this, but the Digilent unit linked has an arbitrary waveform generation capability, that is it can generate a signal to be injected into a circuit under test. So while it is an inferior oscilloscope to similarly priced dedicated units, it does have additional capabilities.

It also apparently has a network analyzer capability, that is, the output signal is injected into a circuit and the response is analyzed via the input capture. This sort of thing is handy if one is building analog signal processing circuits, filters, amplifiers, and such. It should be fast enough to do audio up to low HF frequencies.

The Digilent also apparently has 16 channel 100 MHz logic analyzer capability.

That said, faced with the same decision in the past year, I purchased an oscilloscope model similar to the one identified in post #2, the DSO5102P.

How do you like your DSO5102P? Does it do what you need or are there some features you would like to have.

ov10fac: How do you like your DSO5102P? Does it do what you need or are there some features you would like to have.

I wish I had sprung for the 4 channel model.

There are a lot of compromises versus the stuff I use at work (Tektronix) but it comes at less than 1/3 the price of something from that line. The power button in particular is kind of flaky but it's fine once it's on. It's noisy at the lowest signal resolution (10 mV/division). The screen resolution isn't great. It has the capability to be used as a USB data capture device, which I haven't used.

On the other hand it was only about $220 and way more capable than what I was using previously (Hitachi V-15B, a 15 MHz BW single channel CRT scope that I paid $100 for second hand 20 years ago).

In summary it meets my hobbyist requirements, but it's clearly built to price.

MrMark: I wish I had sprung for the 4 channel model.

There are a lot of compromises versus the stuff I use at work (Tektronix) but it comes at less than 1/3 the price of something from that line. The power button in particular is kind of flaky but it's fine once it's on. It's noisy at the lowest signal resolution (10 mV/division). The screen resolution isn't great. It has the capability to be used as a USB data capture device, which I haven't used.

On the other hand it was only about $220 and way more capable than what I was using previously (Hitachi V-15B, a 15 MHz BW single channel CRT scope that I paid $100 for second hand 20 years ago).

In summary it meets my hobbyist requirements, but it's clearly built to price.

Thanks for the information. What would be the advantage of a 4 channel other than the obvious ability to view four signals at once. Right now I'm having difficulty visualizing why I would want to see two channels at once.

Relative timing is often important, 2 channels is the minimum you can usefully have for this. Consider I2C and SPI busses for instance. And often you want to see that the output of some circuitry is responding correctly to the input.