Member Since: March 13, 2008

Country: United States

  • Yeah, I love Matlab, too…when someone else pays for it. In my case, I have it at work. But at home, I don’t want to spend $2125 for a license (plus extra for individual toolboxes like the Signal Processing toolbox). Sure, if you’re a student, you can get it for $49-$99, but I don’t meet any of their requirements:

    “Student software is for use by students on student-owned hardware to meet course requirements and perform academic research at degree-granting institutions only. It is not available for government, commercial, or other organizational use.”

    So, for my home/hobby hacks, I can’t use Matlab. I have to use Python+NumPy+SciPy+Matplotlib. This python-based stack isn’t nearly as nice as Matlab, but it gets the job done.

  • Thanks for the reply. Swapping around the point of view is helpful. You’re starting with the interference signal and with the mixture. Using this adaptive filter, you can remove the interference from the mixture to reveal the desired signal. Much better. Totally got it. Thanks!

  • Oh, and because I forgot to mention it, I’m a big fan of anyone who writes about signal processing. Thanks for taking on this topic!

  • I think that I missed something important at the beginning. It appears that we’re using an adaptive filter to make y(n) the most like d(n). But, if you already have the signal that you want (ie, d(n)), what is the point of this filtering approach? If you want d(n), you already have d(n). Weren’t you done before you even started?

    Clearly, I’m missing something fundamental. Can anyone clear up my misunderstanding?

  • Great, great post. Love the history, love the now, love the future.

  • Note that these long 500mm soft pots have a resistance of ~20 kOhm, not 10 kOhm as stated in the product description. It’s the shorter soft pots that have the 10 kOhm resistance.

    And for the record, my 500 mm soft pot has a resistance of about 17.5 kOhm.

  • Love the box wall!

  • Experienced Arduino (and Teensy) user here. New to the Photon, though. I got a Photon free from Sparkfun (thanks guys!) as part of a competition. Sadly I had a pretty bad first-day user experience. IMO, new users on Windows should beware…

    When I arrived, I unboxed it. Very very attractive packaging. The packaging pointed me to, so I went there as instructed. After pointing out its physical features, it wanted me to connect to it via my iOS or Android device. It also offered for me to “Connect over USB” instead, so that’s what I selected. I’m a Windows 7 user, so I followed the specific instructions for Windows.

    First, I grabbed the latest node.js installation, as instructed. Later I learned that Photon might not be compatible with Node 4.0 (though I don’t think that this was my issue, yet), so I uninstalled 4.0 and re-installed an older version. Annoying, but easy enough. I restarted my computer, as instructed. Also annoying, but easy.

    The instructions then say to download the latest Photon driver. I did so. I plugged in the Photon, as instructed. It showed up as a Teensy. Unexpected, but OK. I did “Update Driver”, as instructed by the Photon instructions and pointed Windows to the new Photon drivers. It seemed to work fine. It might make my Teensy experience annoying later, but let’s not worry about that now.

    Continuing with the instructions, I opened a command prompt. I issued “npm install -g particle-cli” to install the photon’s command line interface. It bombed out. :(

    The problem appeared to be with serialport@1.7.4. The error messages say that it couldn’t find VCBuild.exe. There was no mention of this possibility in the getting started docs.

    To solve the issue, the command line error suggested that I either install .NET Framework 2.0 SDK (hello 2006) or to install Microsoft Visual Studio 2005 (um, hello 2005). I foolishly tried to install .NET Framework 2.0 (not the SDK), but Windows wouldn’t allow it. I then realized my error and went to install the SDK. I saw that the SDK was 354MB and figured that something wasn’t right with this whole installation process.

    I then pawed through their website a bit to find some help. It’s beautiful and heavy on the self promotion, but not a lot of info on the setup troubleshooting. Finally, I ended up on their github for the command line interface, where it said this:

    “Version 1.4.0 of Spark CLI includes Photon setup support for OS X only at the moment. Windows and Linux support are imminent.”

    Yeah. Thanks. There was no mention of this is the “Windows” section of “Getting Started”. Might have been a relevant thing to say? I think so. My vote is that Photon is not ready for prime time. Sorry, guys.

  • I would love an audio shield, like the one available for Teensy. Yes, I could mod the Teensy audio shield, but it’d be better to get a shield properly configured for Photon directly out of the box.

    If you do build such a shield based on the Teensy approach, it would be great if you could iterate a bit on the power supply filtering…or whatever causes the background chatter on Teensy’s audio board.

  • Sadly, we viewers can never be satisfied…

    Might I offer the observation that, despite the new acoustic treatments, there is still quite a lot of short-period echo in the audio stream. :( Since the panels aren’t doing it, have you considered using more beards?

    While your front-of-camera talent is totally doing his part (rockin' beard, Rob!), perhaps your behind-the-camera staff needs to step up, too. Come on…show some teamwork here, people.

    “But…” you (Mr Sparkfun) might say “…my videographers are women”. Well, that need not be a hurdle, because these sound-absorbing beards need not be real beards. Fake beards are are well-known to have very similar acoustic absorption properties as real beards*.

    [*this claim has not at all been scientifically confirmed. Readers, seize this opportunity…the modeling and measurement of the acoustic properties of beards would be a perfect PhD thesis]

    So, for next week’s video, I implore you, please, go strap on a bushy fake beard and do your part for Sparkfun acoustics! Love. Sparkfun. Beards.

No public wish lists :(