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Daklu

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Everything posted by Daklu

  1. That's in line with what I remembered, but I didn't want to spread misinformation. (Age plays havoc on my memory.)
  2. My apologies if I misrepresented what you said. Can you elaborate on why you recommend against using XControls?
  3. I am under the impression XControls have more or less been relegated to the rusty nails bin. I know I've seen NI employees recommend against using them in presentations.
  4. Nope. AFAIK the only way to set a class constant value is to write a VI setting the object's value, then copy the object with the desired values from an indicator and paste it onto the block diagram. I (as most developers I know) generally avoid using class constants on block diagrams and have adopted something more like what Dan suggests. Good ideas win out... For example, all my classes have a "Create <MyClass>" method that more or less acts like a constructor. The only time I ever drop a class constant on a block diagram is for typing operations (eg: upcasting or downcasting an object) or inside the class' Create method. You can use either parameters passed into the Create method or accessor methods to set the value of the object--it's a design decision. I quit using class constants to instantiate objects (other than in the Create method) primarily because it reduces flexibility. When I see an object wire on a block diagram, I want to know that object it going to work correctly. If a class has a reference-based construct--such as a queue--as a member, then an object instantiated from a class constant is not going to work until I call a method (eg: Init) that obtains the queue and stores it in private data.
  5. I agree none of this is a trivial task and recompiling NI Linux RT to run on an x86 processor might be easier. I haven't looked at the source code (and have never recompiled Linux), do you have any idea how much code would need to be changed to support an x86 processor? My gut says more than I'd be comfortable with. FWIW, QEMU looks the most promising of the VMs I looked at.
  6. I was thinking more along the lines of a direct ARM VM, not an ARM emulator running inside an x86 VM. There are a few out there... I haven't had a chance to try any of them yet.
  7. No, I haven't tried to do this. I didn't know ARM-based VMs were available.
  8. Wow... was it really four years ago that we talked about this? Time flies when you get old... I don't think I've used futures again since this thread** so I can't speak to the attitudes of the larger community, but my terminology preference is "future token" and "redeem." I do agree with Shaun though, it probably doesn't matter as long as you communicate it effectively and are consistent. [**My development focus over the last several years has shifted from pushing boundaries on actor-oriented and messaging systems to figuring out how to refactor, componentize, and deploy an NI-RT application across different target platforms.]
  9. I've never thought of eliminating the object out for methods that do not change state... interesting idea. One side effect of doing that is you are also ensuring no child classes can ever change their state in the overriding method either. That may or may not be desirable in any given situation. Just out of curiosity AQ, how do you arrange your block diagram when making calls to multiple non-state-changing methods? Do you just run the class wire underneath the methods that don't return an object?
  10. No, I didn't. To be honest it ended up on the ever-growing pile of partially finished things I hope to get to sometime.
  11. Jeff, I gave NI my test code and they confirmed it was an existing CAR. It is reportedly fixed in 2013 SP1, but I have not confirmed it yet.
  12. The only way to guarantee Labview loads the correct version into memory is to close and reopen the project. Sometimes LV will notice the version on disk is different and ask if you want to revert (which in this context means 'load from disk,' not 'undo any changes you made') but I wouldn't bet on it noticing every time.
  13. Hey Jon... you coming back to Labview or just stopping by for a visit?
  14. All this talk of television shows and not a single mention of House of Cards? Unacceptable! (I keep thinking I ought to try the British version.) I'm finding I'll be interested in a televised drama for a while then get bored--mostly because nothing substantial is happening. Revenge started out good but partway through the first season I realized the story wasn't going anywhere. Arrow has a back story I find a little bit interesting, but again there's no progression. I really enjoyed Weeds for a while--until it became too dark and I wearied of watching Nancy's self-destructive behavior. Tried both Mad Men and Breaking Bad. Neither struck a chord with me. I'm a little more forgiving of sitcoms. I enjoyed the early seasons of Big Bang, though I've never particularly liked Penny. Been watching 30 Rock, and that's okay. By far the best sitcom I've seen in the last 2 decades is Scrubs. (And Zach Braff nailed an awesome photobomb the other day.) There aren't that many "good" web series. I mostly enjoyed The Guild, probably because I was way into World of Warcraft for a while and could relate to the situations. But it pales in comparison to the best web show I've seen: Dr. Horrible's Sing Along Blog. If you're willing to include Machinma in the web series category, Arby 'n' the Chief was pretty funny. (If you're not familiar with it, start from the . BTW, it's not safe for work.)
  15. For the money you might be better off purchasing a Labview RIO Eval kit.
  16. Wait, are you saying that changing a class' library membership doesn't reset the mutation history in 2013?
  17. Huh... I have the Raspberry Pi User Guide and didn't see any references to using the labeled pins as GPIO. Thanks for the link.
  18. Okay, okay. Enough already... I ordered a Uno off of Ebay for <$13 including shipping. We'll see how it goes.
  19. Shaun, Yeah, Danny mentioned the Pi earlier. Unfortunately, the Pi only has 8 GPIO pins. This board needs 10. Multiplexors or serial I/O options are possible, but this is a project for high school students in their second year of programming who will have limited help and supervision. The environment must be simple enough to set up for them to make progress quickly. Jordan, I see two different ways to approach using the Uno. The first is to program the microcontroller using c/c++ to control the lights on the circuit board directly. The second is to write firmware and have the student use the Uno as a usb digital I/O module, which is what Darin was suggesting. What kind of experience have you had using the Uno as a standard usb device? Have you had any troubles getting it to work well? (As an aside, since the Uno comes with a usb port it potentially sidesteps the problems others were having with the FTDI chips.)
  20. I bought the OEM version... $75. Yeah, that's still a lot of Arduinos. I might pursue firmata on my own, but I'm very concerned there will be too many difficulties getting in the way of the student's success. In particular, it appears they'd have to use a USB serial port and there looks to be some issues with that. Not a big deal for an engineer--potentially a project killer for a high school CS student working independently. (What arduino would you recommend for a simple digital I/O module?)
  21. Thanks for the leads. I ended up purchasing a LabJack U3. They don't have a Java API for that model, but it does support Python, and they are introduced to Python at the end of the first year. The firmata library looks very interesting. Unfortunately there are just too many unknowns for me to be confident I could give them something soon enough. (Namely I have no practical experience with Java, Arduino, or fermata.)
  22. My daughter is taking a high school computer science class and learning Java. I met with her teacher last night as part of a "technical advisory board," and she asked for some projects her second year students could work on independently. (Second year CS students attend the same class as the first year students, but for the most part they choose their own projects and work on them independently.) Being a hardware guy, naturally I think programming is more fun when there are flashing lights and moving parts. A couple years ago I purchased a "traffic light kit" that is kind of neat and dirt cheap. However, writing a desktop app for it requires a digital I/O module with a Java API. Unfortunately there doesn't seem to be much Java support in the hardware community. Does anyone know of a low cost USB digital I/O module that comes with a Java API?
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