Ideas Test

2 VOTE

USB Oscilloscope with faster sample rate and wider bandwidth

I currently need a USB oscilloscope which can capture long time durations with sufficient detail. Logic PRO does not have a fast enough sample rate nor wide enough analog bandwidth for my needs (on this project).

There is nothing that I can find on the market for lets say 2 channel which streams to the PC for storage with a high sample rate and decent bandwidth. I know this is not a normal persons use but there have been several projects which would require this thus far and I have been limited by all of the oscilloscope capture depth.

My last project I was using a 1 wire device and I was lucky that I could use the logic 16 and only care about the digital level and ignore the rest of the analog information but that information is critical at times. (especially when you are trying to bus power your 1 wire device you need to be able to see the voltage level not just high or low)

I would also need this oscilloscope to be able to interface to your GUI and have a way to decode the analog waveforms rather than trying to decode things in the digital domain. For example decoding ASK modulation which would not show up in a digital domain logic analyzer.

  • Avatar32.5fb70cce7410889e661286fd7f1897de Guest
  • Jun 26 2018
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  • Avatar40.8f183f721a2c86cd98fddbbe6dc46ec9
    Guest commented
    June 26, 2018 19:10

    I have this one http://fanyit.com/review/hantek-best-usb-oscilloscope-review/
    if you like try with this may be will e good for you

  • Avatar40.8f183f721a2c86cd98fddbbe6dc46ec9
    Guest commented
    June 26, 2018 19:10

    That doesn't sound like Saleae's focus. If you need such a high-end oscilloscope:

    https://www.picotech.com/products/oscilloscope-specifications

  • Avatar40.8f183f721a2c86cd98fddbbe6dc46ec9
    Guest commented
    June 26, 2018 19:10

    The data can be greatly compressed, to about 2 bits/sample for each channel, for the common case where the signal is not constantly and rapidly changing. Use a 2-bit code: 0=no change 1= signal changed by +1 count, 3=signal changed by -1 count, 2= signal changed by some other amount, described by next 4 bits...

  • Avatar40.8f183f721a2c86cd98fddbbe6dc46ec9
    Guest commented
    June 26, 2018 19:10

    Lets's say you want 50MHz scope, 2ch 8-bit. to stream over USB3.0.
    Data rate is 5Gb/s or ~600MB/s.

    Let's cut that in half since other devices need the bus and windows (or any OS) doesn't stream from 1 device at anywhere near 100% of the full data rate.
    300MBs/sec gives us a maximum data stream of 300 MSPS - overhead, so lets chop in half again.
    150MSPS accross 2 channels gives us 75MSPS per channel.
    For a 50MHz scope you would want a minimum of 200MSPS but most would like 500MSPS

    Let's look at that 150MSPS, storred as ASCII (CSV), that expands to 1.2GB/s for a comma, carriage return and 3 digits for raw ADC counts. (more for having neatly converted numbers with units).

    To store 1 minute of data would take 72GB.