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Everything posted by abc

  1. Bought this: http://www.ebay.com/itm/181409484752?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT 10pcs 6mm 2 phase 4 wire micro-stepping motor Canon with a small plastic gear for $2.58 Figured, at this price, we might use them for something. What are they good for? Could one make a robot (a tiny "creature") out of these, with a little Polymorph or 3D printing? It does not specify the torque, I expect it to be tiny. BTW, I've read more about Polymorph and am in love with it. I'd buy servos if I saw them at this price. Still looking. Suggestions would be great
  2. I mean, generates more voltage spikes? I've heard that a 5V servo can create a 100V spike, is that true? I understand that's why servos require a couple of diods and maybe a capacitor, to get rid of the spike? I meant $1/oz for Polymorph, not $1/lb of course. I've also read somewhere that one can use hot glue for the same purpose, has anyone tried that?
  3. Someone had told me that servos are more sparky than steppers and thus require more circuitry, is that true? I don't mind it over the long run, but it's nice to start with something simple. Someone had recommended me Polymorph plastic (very strong and durable plastic that becomes soft and pliable at 60 c). I am fascinated with this stuff, but it's $1/lb, and that probably means smaller robots. (Though I've also read that a cheaper alternative is glue from some hot glue sticks - but I wonder if they are as safe, etc.) Is there a place on this forum or elsewhere for discussing the mecha
  4. abc

    A buffer?

    I've been reading up on using some sort of a $.50 hex buffer in order to shield the board from power fluctuations, short circuits and other newbie mistakes. Seems like a great idea! In fact, I wonder why it's not routinely done, at the entry level at least; but I must be missing something. What are the disadvantages to using this approach? And what buffer, if anything, would you guys recommend? (Same application, for the use by a 10 year old, to work with some motors, LEDs and what not). Putting things more generally, what other measures can be taken to protect from newbie mistakes? My fir
  5. Thank you all so much for the wealth of info! Do we need an anti-static wrist band? I am thinking probably not, with hardwood floors and humid climate. Am I right?
  6. This is getting more and more OT, but.. what do people think of electric ink and electric glue? Seems like a good idea, but its popularity seems pretty low, why?
  7. The steppers I linked to are $12 for a 5-pack. As for simplicity, I am a bit confused, because I've just read this:
  8. Thank you. I've canceled my order and went with the one you recommended. Since you all are so nice... this motor: http://www.ebay.com/...=item3394d5ad89 - is there some sort of a standard part that can be put on the axis? How do I attach things to the axis?
  9. Thank you for the feeback, abecedarian. I wonder what the price difference might be, from the top of your head (if I was to buy those things separately), and whether the book makes up for it. I won't have much free time, so a good simple book might be a life saver. Then again, the O'Reilly book can be rented for $6 on Kindle: http://www.amazon.com/Make-Embedded-Projects-Hardware-Discovery-ebook/dp/B00DBIEYIC/ref=tmm_kin_rent_0?_encoding=UTF8&selectObb=rent&sr=8-1&qid=1411173810
  10. I am afraid we'll have to start with Arduino after all, simply because all starter kits that I could find come with an Arduino board anyway.. unless someone knows of a kit that does not? This may be OT (or not, since all these peripherals and documentation can be reused with Energia, right?), but I'd really appreciate an advice of which kit to buy. I've narrowed down my search to two kits. http://www.amazon.com/16Hertz-UNO-Ultimate-Starter-Breadboard/dp/B00KGF0ZD6/ref=lh_ni_t?ie=UTF8&psc=1&smid=A3B2Y7HLMJUU6V and http://www.amazon.com/Arduino-Ultimate-Starter-Includes
  11. will a self-powered USB hub help? Or even bus-powered, for that matter. Short-circuit happens.
  12. One more question: how do I protect my computer's USB port from power surges and such? I've burned one port already!
  13. Might have found a solution. We went to the thrift shop and boght 1) a Barbie doll (her knees and elbows only bend in one direction ==> may move them with just one stepper motor per extemity? They would hopefully bend on their way forward and stay firm on the way back, thus propelling the robot. Especially is I add some teflon to the toes and rubber to the heals? 2) A $5 Furby. How hard is it to hack a Furby and take away its eyes, legs, beak, etc and put them into the robot? Edit: found plenty of materials on hacking a Furby: http://www.instructables.com/id/Hack-Your-Furby-int
  14. Is this a good purchase? http://www.ebay.com/itm/5-Pcs-DC-5V-Stepper-Step-Motor-Driver-Test-Module-Board-ULN2003-For-Arduino-/221540363657?pt=LH_DefaultDomain_0&hash=item3394d5ad89 I don't understand why a stepper motor requires a separate "shield" or some other sort of a board. I was hoping a stepper motor just takes raw input? What input does it take, and what does the board do? Could have researched myself, but am under a major time crunch, have to come up with some sort of an idea by tonight.
  15. Raspberry PI sounds like a great option, but got to stick to the budget. And the budget is tiny. On the last Mini Maker fair, I saw a Raspberry PI-looking computer that they said was purchased in Oregon for $10, case included. Any idea what that was? Also, I've heard there was some sort of a giveaway very recently, or something that was described as "Raspberry PI on steroids"? Is that still around? Thank you everyone and I hope this thread is not too OT!
  16. Hi all, My kid has been programming Scratch for a few years now. I think this may be a good time to introduce him to the embedded world. I am trying to decide between Energia, Arduino and, well, Scratch (which also has robotic functionalities). For a school project (which does not have to include electronics of course), he has a choice of 1) adding some sort of simple electronic functionality to an animal, or 2) sensing sound frequencies and responding in some ways. The project has a limited budget (they have not told us yet exactly how limited, but it has to be low). Scratch wo
  17. I've been absent from the list all this time, and then come back for all this practical wisdom! Thank you all! As a software developer - this seems overwhelming. Should not there be houses who specialize in all this work? I don't feel like reinventing the wheel, competing with the pros. Not my core expertise, by far. Maybe I'll stick to what I know, i.e. software.
  18. I think there is a highly expedited certification process, if any, for those who use pre-certified software/hardware. Other than the radio, what is involved? I am mostly wondering whether I can/should get simple pre-fabricated casings.
  19. I am going to sell a complete product. I think I should not have to worry about FCC approval, as long as I use an established stack & hardware (e.g. Bluetopia stack on TI/Panasonic chips)
  20. Sorry if this is slightly off-topic. Now that I've got into embedded programming, I am contemplating all kinds of industrial and consumer electronic products I could make. Problem is, I've never produced anything other than software. I understand this is highly specific to a product and there are no one-size-fits-all solutions, but I'd like to hear some gotchas, keywords, leads, success stories, failure stories, etc. For instance: what if I am manufacturing tiny (an ounce or less) consumer electronic devices, for indoor use. They communicate wirelessly, no buttons or screens, just a bu
  21. Hi, I am using Energia and thus GCC toolchain. I get the above message in the subj. on every compiled file, in Debug view. Also, I can not step-return, and my stack always shows only the function I am in; is that related? Thanks
  22. I've been reading this article: http://www.ti.com/lit/an/slyt356/slyt356.pdf So, according to the article, current depends on voltage linearly. How does clock speed depend on voltage? The way I understand the article (and it may be entirely incorrect) that it does not; except, not all clocks will run at all voltages: Is my understanding correct? And what happens to a clock when the voltage is too low? The article does not say anything about the merits of executing faster and, as a result, sleeping more. So.. for a very slow, very low power app, which voltage is
  23. I meant to say "burn out", not "burn". As in, a pin burning out. Also, I am wondering about which chip is more vulnerable to mechanical damage, humidity, etc. Has somebody compared mechanical durability of various chips? As for bugs, thank you for mentioning that; I probably underestimated this concern. Is it safer to go with tested and true, for a commercial project? Or would you say EFM32 is fairly well tested by now?
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