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abecedarian

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  1. Like
    abecedarian reacted to bluehash in Airdog Airleash - How does this even work?   
    Compasses get screwed up when near power lines or anything metal. There must be something else. EEVblog needs to take it apart.
  2. Like
    abecedarian reacted to bluehash in Airdog Airleash - How does this even work?   
    There is this awesome kick starter about a quad following you in 3D space. They have something known as "airleash"
    https://www.kickstarter.com/projects/airdog/airdog-worlds-first-auto-follow-action-sports-dron
     
    Anyone know how they can triangulate at a point using only one reference? Is it radio RSSI? There are no visual fiducials/trackers. (scratch head )
     
  3. Like
    abecedarian reacted to bluehash in Airdog Airleash - How does this even work?   
    .. Good point. But how does it pan towards you?
  4. Like
    abecedarian got a reaction from bluehash in Airdog Airleash - How does this even work?   
    Says it has a wireless transceiver that straps to your wrist (later could be helmet, et cetera).
     
    I imagine if the AirLeash has GPS and the AirDog as well, it shouldn't be too hard to derive a bearing.
  5. Like
    abecedarian got a reaction from tripwire in Propeller open-sources P8X32A processor   
    http://www.parallax.com/microcontrollers/propeller-1-open-source
     
  6. Like
    abecedarian got a reaction from bluehash in Propeller open-sources P8X32A processor   
    @@bluehash
    Not really sure the motivation. But I think this raises the bar for everyone else in the MCU marketplace. I mean everyone: Atmel, ST, TI even, might just have to bring something like this to the table.
    And with the core 'open', who knows where it will go.
  7. Like
    abecedarian got a reaction from roadrunner84 in Propeller open-sources P8X32A processor   
    http://www.parallax.com/microcontrollers/propeller-1-open-source
     
  8. Like
    abecedarian got a reaction from bluehash in Propeller open-sources P8X32A processor   
    http://www.parallax.com/microcontrollers/propeller-1-open-source
     
  9. Like
    abecedarian got a reaction from greeeg in Propeller open-sources P8X32A processor   
    http://www.parallax.com/microcontrollers/propeller-1-open-source
     
  10. Like
    abecedarian got a reaction from Smakkemeken in Mobile skin post test   
    Yeah, me late again.....
     
    Have to agree it looks fine on my LG Optimus M... not that I'll do much posting from the phone since it is Metro PCS.
  11. Like
    abecedarian reacted to igor in Well... crap.   
    Well, at least you should be pleased you have the heat gun, after all Happiness is .... ,
    well, I can't quite bring myself to say it. 
  12. Like
    abecedarian reacted to WethaGuy in Well... crap.   
    I'm in the process of moving and have one packed away in a moving box somewhere around here.  I'm not going to have a chance to mess with it for a few months, at least.  You're welcome to it (if I can find the box it's in, hmmm..).
  13. Like
    abecedarian reacted to bluehash in Well... crap.   
    Aww man! @@abecedarian, you totally get an award for this. Check it out
     
    I don't have that display. I have the 5x20 line one. You can have it if you want.
  14. Like
    abecedarian reacted to RobG in Arrow's Black November - Complimentary Shipping on Any Online Order   
    I understand that MyArrow might make sense when my order is >$200, but the problem I have is lack of information and miscommunication.
    I just can't believe they are not able to give me my final invoice at checkout.
    Again, it's just $8, but I hate the way they do business.
  15. Like
    abecedarian got a reaction from KatiePier in programming tool -language for children   
    The trick is keeping them interested long enough to learn something. Dealing with short attention spans is always a problem- immediate feedback / results are required. You can't hand a child a Launchpad and expect more than them flashing the LED's when they push a button on it, and then they're bored asking you things like 'now what'? More functionality requires additional hardware, and now you're trying to teach electronics engineering while teaching programming.
     
    My 9 y/o nephew is somewhat fascinated by the tools and things I have here in my room but would rather build things with Lego's. Maybe start there, then segue into using NXT and other things with the Lego's?
     
    And by all means enforce the concept that there are many paths to a destination. Python is good for some things while Java and Basic are good for others; C and its derivatives are good for things too. But nothing is worth anything if the underlying hardware isn't well understood.
     
     
    ... and I find myself still trying to come to grips with it all....
  16. Like
    abecedarian reacted to oPossum in "spikes" in the ultrasonic reading   
    Using a 74HC238 to limit transmission to only one module may be helpful. With all of them sending all of the time there may be problems with echos from the transmissions of other modules.
  17. Like
    abecedarian reacted to roadrunner84 in Job offers on 43oh   
    And I am sorry for outing myself a bit harsh, I did not mean to be rude. My apologies.
  18. Like
    abecedarian got a reaction from roadrunner84 in Job offers on 43oh   
    I agree completely. But I think the thought was that there would be a sub-forum of 43oh for the people looking to subcontract development, not turning 43oh into a subscription service. So I suggested that sub-forum could be moderated so that only people who paid to post in it could, but at the same time it would be free for anyone to browse through. Think like the help-wanted section of many newspapers, or those big-name job-search websites, where anyone can look but only paid advertisements are accepted for publication.
    Well, the last suggestion was about allowing users to post resume's. It could be an attachment uploaded to your profile, and maybe an icon under the avatar to let people know you might be looking for side-jobs or employment. And I admit maybe it was slightly off topic, but not entirely, since resume's are about getting work.  

    Fair points. And around here there's a mail-out called "The Pennysaver" that is free to post any personal-type ad for items as you mention- second-hand/used goods, goods wanted, et cetera, and it is paid for by the advertisers who for the most part can't afford radio or TV spots. 
    But there's always a way to circumvent the system.
     
    Sorry if I pushed the wrong button; no offense intended.
  19. Like
    abecedarian got a reaction from Duloxetinepka in Invalid HTML5   
    http://validator.w3....C_Validator/1.3
     
     
    That might explain why I have to click twice "quickly" or copy and re-paste things and post again, in IE9(&10) before the site processesses them.
  20. Like
    abecedarian reacted to Fred in Windows IoT program   
    Smart meters are there entirely to suit the company that supplies them. The idea that consumers benefit is just marketing fluff. They save money on sending or someone to read the meter and they can cut off the supply remotely of you don't pay the bill.
  21. Like
    abecedarian reacted to rockets4kids in Oversampling, averaging and getting confused.   
    The first is a simple average and the second is a weighted average.  Which is preferred depends on what your goals are.
  22. Like
    abecedarian reacted to greeeg in Oversampling, averaging and getting confused.   
    To complicate the matter further you can alter the weighting in a weighted average.
    BattVolt = (BattVolt + BattADCValue*3)/4; This will respond quicker to changes in the current battery voltage. useful if the sample rate is low, (order of seconds or minutes)
     
     
    These are just technically just low-pass filters.
     
    If you can isolate where your noise is actually coming from, (sleep CPU while performing, isolate AVCC from DVCC powersupply) you may be able to remove, or improve, the need for filtering.
  23. Like
    abecedarian reacted to veryalive in Oversampling, averaging and getting confused.   
    think of 'averaging' as a low pass filter in this case.
     
    if you use the 16-sample-then-average (window size 16), then one noise spike in that batch of samples gets strongly reduced.
     
    in the other case, where you take the last sample added to the running average (window size 2, sort of), if the last sample is a noise spike, it will come through distinctly.
     
     
     
    (EDIT 1 - in fact, it's a convolution - a time-domain rendition of a low pass filter - which can lead to some very interesting filtering in a 430 with the hardware multiplier.   A  FIR, if you're a DSP guy.
    Block averaging being a 'rectangular' window.  Other shapes are handy, like sin x / x  or  triangle,  and correspond to the filter's frequency response expressed as the time-domain impulse response.)
     
     
    (EDIT 2  -  and to your question on 'oversampling', this means the sample rate (ADC rate) compared to the highest signal frequency of interest (eg: the change in temperature of a room).   
    In many uController apps, our sample rate is much higher than the signal's rate of change  ----   eg:   Ksamples/sec vs Degrees C per second    --- and this is an example of oversampling.  You can throw away samples (decimation) if you want to reduce computation / memory array size / etc  without significantly reducing the fidelity.  Note, FIR filters have a delay.
    Much of this is equally - or better - handled in the frequency domain.)
  24. Like
    abecedarian reacted to grahamf72 in Oversampling, averaging and getting confused.   
    I'd typically use the first method when measuring something that changes slowly compared to the sample rate. The second method would be when the thing being measured is likely to rapidly change and the most recent result is the most important. For example if I was sampling barometric pressure, I'd use the first method for a weather station, but the second method for an altimeter.
     
     
    Sent from my iPad using Tapatalk
  25. Like
    abecedarian reacted to greeeg in Oversampling, averaging and getting confused.   
    I just whipped up this quick example in excel.
     

     
    In this case +-10% was added to a constant value 100.
     
    we have a 5x oversampled.
    50% weighted, A = (A+B)/2;
    10% weighted, A = (A*9 + B)/10;
     
    I would recommend doing something like this to evaluate which method would work best. preferably on real data.
     
     
    For example if your input signal changed values suddenly.

     
    The same filter might not be appropriate.
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