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Suggestions for a digital oscilloscope — Parallax Forums

Suggestions for a digital oscilloscope

MJHanaganMJHanagan Posts: 189
edited 2013-02-11 13:26 in Propeller 1
My next hobby acquisition is likely to be a digital oscilloscope. Primary uses will be for monitoring I/O lines (e.g. watching SPI communications) and some fairly slow varying voltage signals (<1kHz). I'm a newbie so probably a 2-channel would suffice and I don't think I will need anything faster than ~1 MHz.

I have been eyeing these Tektronics TDS's on eBay which seem to be selling for ~$400 (TDS1002B). I also looked at the Propscope which sells for about half the cost ($200) and can handle 4 logic input lines.

Are there any compelling reasons to consider a standalone DSO over the Propscope? Are these Propscopes reliable?

Comments

  • KMyersKMyers Posts: 433
    edited 2013-02-10 08:50
    Hi, I have a Bitscope 100 and it works great for working with micros. It has also a 8 bit logic analyzer great for watching I/O's etc.

    www.bitscope.com
  • ChrisGaddChrisGadd Posts: 310
    edited 2013-02-10 10:53
    A standalone is useful if you do any work away from the computer ... probably not an issue here. What might be an issue, two channels is pretty limiting--even SPI has three or four lines to watch. I use a Digilent Electronics Explorer Board. Four channel oscope, 32 digital I/O lines, 2 waveform generators, fixed, variable, and reference power supplies... I just plug a 40-pin Prop into the breadboard area, wire up a few pins and a header for a prop-plug, and I'm all set. It's a bit pricey, but I consider mine well worth it.
  • evanhevanh Posts: 15,944
    edited 2013-02-10 13:17
    ChrisGadd wrote: »
    I use a Digilent Electronics Explorer Board.
    Looks interesting. I note there is $200 dual channel version also - Analog Discovery.

    Couple of questions:
    - Is the 40MS/s (analogue in) shared between all four channels or is it 4x 40MS/s?

    - 10 bit resolution (analogue in) is nice. Is there any exceptions like only below certain sample rates? How clean is the signal?

    - I note the 16kS/ch built-in capture capacity. Can it be configured to sample indefinitely or at least for mega-samples per capture by streaming continuously, and live display, back to the PC?

    - The picture shows only the bread board and no BNC adaptors. There is a quad BNC adaptor for it's smaller (Analog Discovery) brother. Is this also usable, or an equivalent, on the Electronics Explorer?
  • MJHanaganMJHanagan Posts: 189
    edited 2013-02-10 17:36
    The Analog Discovery looks like a very handy device. More logic I/O channels than the Propscope so this might be an advantage when debugging the the Propeller. Thank you for the suggestion!
  • HannoHanno Posts: 1,130
    edited 2013-02-10 17:43
    The PropScope expansion port has 16 IO that connect direct to the Propeller in addition to 2 I2C lines.
    The expansion card that comes with the PropScope uses 4 of these for LSA readings- but if you needed more you could make a custom card.
    Hanno
  • evanhevanh Posts: 15,944
    edited 2013-02-11 04:46
    Just gave the software a test drive under Wine. Seems to work surprising well considering it needs a recent version of dotnet. I managed to get away with just dotnet 3.0 since that's the latest that easily installs under Wine. That was enough. Install commands were:

    $> WINEARCH=win32 winetricks dotnet30
    $> WINEARCH=win32 wine digilent.waveforms_v2.2.4.exe


    Then to run it while hiding the pile of errors from spewing:

    $> WINEDEBUG=-all WINEARCH=win32 wine 'c:/Program Files/Digilent/WaveForms/WaveForms.exe' >/dev/null


    The simulation works fine. Don't know if it can connect to real hardware though, which is where PropTool falls over.
  • dMajodMajo Posts: 855
    edited 2013-02-11 08:17
    MJHanagan wrote: »
    My next hobby acquisition is likely to be a digital oscilloscope. Primary uses will be for monitoring I/O lines (e.g. watching SPI communications) and some fairly slow varying voltage signals (<1kHz). I'm a newbie so probably a 2-channel would suffice and I don't think I will need anything faster than ~1 MHz.

    I have been eyeing these Tektronics TDS's on eBay which seem to be selling for ~$400 (TDS1002B). I also looked at the Propscope which sells for about half the cost ($200) and can handle 4 logic input lines.

    Are there any compelling reasons to consider a standalone DSO over the Propscope? Are these Propscopes reliable?

    For your target price but far better bandwidth have a took at these scopes:
    http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1052e/ 50MHz DSO
    http://www.rigolna.com/products/digital-oscilloscopes/ds1000e/ds1102e/ 100MHz DSO

    and for a little higher price:
    http://www.rigolna.com/products/digital-oscilloscopes/ds1000d/ds1052d/ 50MHz MSO (dual analog + 16 digital)

    Todays Rigol scopes are really good. Some good friends (heads of www.AllData.it company, who sale test equipment/bench, also in the military field) has told me that they have many USA customers which require expressly Rigol scopes as part of test bench, some of them installed in the usa army tanks.
  • evanhevanh Posts: 15,944
    edited 2013-02-11 13:26
    I saw some of those in a local shop here but they're all two channel so I didn't look any further. However there is some four channel scopes on the Rigol website - DS1074B would be the value scope there.

    I spent several times more money to get a four channel deep capture memory scope a decade ago. Admittedly, I ended up with an 8Mpt/ch scope where as these are only 8Kpt/ch.

    The deep memory is really cool for looking at logic sequences. Often don't even bother with triggering. Just press the stop button and start perusing the captured waveforms.
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