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Thread: Need recommendation for a Beagle USB Protocol Analyzer to use w/ Teensy USB HID/Raw

  1. #1

    Need recommendation for a Beagle USB Protocol Analyzer to use w/ Teensy USB HID/Raw

    I am looking for a way to capture, analyze, and time USB traffic for a few specific cases - measurement, not design.

    Anybody using a Beagle 12 or 480 with Teensy as HID? Pros and cons?

    My use cases, with analyzer(s) inserted on each <-->

    USB Host <--> USB HID Device
    USB Host <--> USB Raw HID device
    USB Host <--> Teensy as HID / Raw HID
    USB Host <--> Teensy HID | Host <--> USB HID Device
    USB Host <--> Teensy Raw HID | Host <--> USB HID Device

    The last two might happen at the same time (two physical connections to a Teensy, e.g. 41+LC combo)

    My initial take was that
    1) I will need two protocol analyzers
    2) Beagle 12 would be sufficient for HID and Raw HID

    Now Beagle USB analyzers come with digital I/O (4+4 pins), and there is some tailoring of software:

    Beagle recommends a

    USB 480 Power Protocol Analyzer - Ultimate Edition

    claiming that
    - the USB HID / Raw HID devices I target should run up to High-Speed USB 2.0 (480 MBps)
    - Beagle USB 12 doesn't allow for triggering or USB class-level decoding

    I don't need power analysis, stop capture triggers.
    I'd like to have the digital I/O (to hook up to another Teensy that measures timings, starts capture).
    I do need the human-readable class-level decoding.

  2. #2
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    I use the Beagle 480 (not "power" or "ultimate"). It works well, though the $1200 prices puts it pretty far outside of hobbyist use.

    The class level decoding is nice. I don't understand why they don't do that on the 12 model, at least when the capture includes all the enumeration. The 480 does the class decode even when you start the capture after enumeration, so my guess is the hardware is capturing the enumeration stuff while the software isn't capturing. The software has 3 different ways to view the data. The class decode is only really valuable when viewing in the higher-level modes, and especially when capturing between the host and a hub which has several downstream devices.

    Normally I use it with an older Macbook Pro which has only 8GB of memory. At 480 speed, even just the nak and ping tokens from inactive bulk endpoints/pipes can consume the capture buffer faster than is convenient. My main recommendation is to capture with a computer loaded with as much RAM as possible.

  3. #3
    Quote Originally Posted by PaulStoffregen View Post
    I use the Beagle 480 (not "power" or "ultimate").
    Thanks for the details and cautions!
    I had budgeted last year for the 480 "Plain" or whatever they want to call it, and was somewhat surprised they pitched the "Ultimate" instead.

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