Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation


About Sparc

  • Rank
    More Active
  1. Compare the magnitude of the number and then choose between %f and %_f. At three digits any value between -0.001 and 0.001 would get %f (fixed precision), everything else gets %_f (significant digits). I may be off a zero, but the premise remains.
  2. If no losses are acceptable and buffers are reused, any mechanism proposed will have this problem. That point is not valid criticism. If losses are acceptable a "no wait" path is provided by reusing a buffer from Q1.
  3. The IMAQ wire is a reference to an image buffer. The data they contain isn't copied unless explicitly copied via IMAQ Copy function or IMAQ Get Bytes function or you wire up the "Dest" terminal on the IMAQ functions. Scenario 1: If the Consumer must process every item sent by the Producer the number of buffers must be a size to store the back log. Whether this size is 2 or 3 or 907 is only relevant when deciding or being constrained by the platform it's running on. Scenario 2: If the Consumer is only required to process as many as it can and losses are acceptable, pick a number of
  4. There's an LED submerged in my cat's water fountain. I had to put the thing together (*some assembly required). That LED lead is literally two wires and some shrink tube. $25 + 35 + Audrino ($25) is ~$85 per drop. 180mm is 7 inches (max). DIY vs. OTS seems like a wash to me. With OTS winning for the reasons people buy OTS.
  5. Taking a trick from racing events: RFID tags in their shoes and RFID tag scanners on the floor near the doorways of the rooms. Maybe not. After checking, the tags are cheap, the readers not so much. Tags: $1.00. Readers: $1000.00. Dropping to a door-acces like reader (which would require the guide to purposely activate) it's about $100 per door. Of course once you're at purposely activating a push button in each room is simpler. Accelerometers? Reset at a known position after after each 'lap' of the maze. A non-trivial amount of DIY involved (microcontroller with WIFI + acceleromet
  6. These aren't the Big Box Specials where they advertise some awesome spec (9 GHz Octocore CPU!!!) and then cripple the entire box reduce cost with some unadvertised component (66 MHz, single channel memory bus)? I've haven't yet had a 32 bit app run worse on a 64 bit machine. I've had them run the same, better, or not at all -- but never worse (at least never so much worse that I noticed). My hunch is the new computers don't have better hardware in all the right places. For instance the existing PCs might be 4 GHz single core and the new PCs 2 GHz Quad core.
  7. VI corruption. The fact a copy/paste of the code works is a strong clue. I've had many inexplicable problems simply disappear by just copy and pasting entire block diagrams in to new VIs. It's almost at the level that the technique is a legitimate debugging step. To paraphrase a friend: "What? You've never seen LabVIEW do something stupid before?"
  8. Assuming you mean a traditional Windows driver, you can't. You'll nee to use the Windows Device Development Kit and it uses some version of Visual Studio and write it C or C++, I forget which. On the other hand, if you make it with a USB interface and HID compliant you won't need to make a device driver. Windows (and just about every other modern OS) will recognize it and use a built in driver for it. There are many microcontroller products/projects out there that ship with a USB interface and HID compliant stack.
  9. Does this do what you want? timeline_lv2009.vi
  10. Turned 'em on using a super-secret and private key in the LabVIEW INI file. That correlates well with some other "research" I've done. There are a handful of VIs down in <LabVIEW>\resource\PropertyPages\ that look liked they'd be used with these properties, but they also appear to be orphans as I can't catch LV ever trying to use them. Thank you for the insight.
  11. The Help description is so tantalizing for these two methods it's almost unbearable: "Property Pages use this for generic get/set of properties." The interface to them is dead simple too: one I32 array, one variant. Sounds pretty ideal for a "Property Saver" type tool. Instead of nested case structures and class coercions you just wire an array and a variant to a Generic class method. Unfortunately, I can't get them to work. I've tried a wide variety of inputs to these guys and so far I've gotten nothing but 1058 errors: "LabVIEW: Specified property not found." About the only thing I ha
  12. My guess is you have a DC offset in your data. DCOffset_8.5.vi
  13. A few times now I've needed to dynamically display and resize some XY graphs. And it never seems to fail that after a few iterations I end up with a chart that resembles this: Or worse, I end up with a chart that has a negative size according to LabVIEW: Once this happens there is no way I have found to manually resize the graph. I have to delete the control and drop a new one, and in the process lose my formatting, local variables, property nodes, event cases, etc. "Replace" gives a new control, but at the exact same (negative) size. Today I was fed up and looked to why this happens
  14. The following will make me push and then push harder a few times before I figure out the problem.
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.