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Scrolling LED "Medals" from Robolympics now available to SX programmers - Page 2 — Parallax Forums

Scrolling LED "Medals" from Robolympics now available to SX programmers

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Comments

  • Ryan ClarkeRyan Clarke Posts: 738
    edited 2005-03-20 19:46
    Just to clarify, I should be able to program these with my SX-key as long as I give them enough power (6v?) correct? (ie the header pins are for the Key..you added the board just to make sure you were supplying enough power (which is inadequate from the battery pack...)

    Ryan
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-03-20 20:06
    LostboY said...
    Just to clarify, I should be able to program these with my SX-key as long as I give them enough power (6v?) correct? (ie the header pins are for the Key..you added the board just to make sure you were supplying enough power (which is inadequate from the battery pack...)

    Ryan
    You are correct, except supplying more than 5V straight to the SX is not suggested (most 5V chips specify 5.5V as an absolute maximum voltage rating), when they specify 6V this is before regulation of the voltage, if you look at the first picture in his last post you'll see the adapter board has a regulator and a DC power plug, this feeds power to the SX-Key and the SX on the medallion.
  • Ryan ClarkeRyan Clarke Posts: 738
    edited 2005-03-20 23:48
    Paul Baker said...

    You are correct, except supplying more than 5V straight to the SX is not suggested (most 5V chips specify 5.5V as an absolute maximum voltage rating), when they specify 6V this is before regulation of the voltage, if you look at the first picture in his last post you'll see the adapter board has a regulator and a DC power plug, this feeds power to the SX-Key and the SX on the medallion.

    Sorry to beat a dead horse (I don't want to destroy the ones I've ordered [noparse];)[/noparse]-

    But 7~12v run through a 7805 should be ok, right? So the battery pack would be enough if it were 4 AAs (1.5 x 4 = 6) to program the chip -

    (Again sorry, I'm still new to the SX chips...)

    Ryan
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-03-21 00:32
    http://rocky.digikey.com/WebLib/Texas%20Instruments/Web%20data/UA7800%20Series.pdf· 3rd page 1st table Vi min 7V, Vi max 25V. The answer is (1) yes (2)·no the DOV of 7805 is 2V -> 5V+2V=7V,· 4xAA=6V<7V. And dont just replace the 3xAA battery pack with a 4xAA pack without also incorporating an LDO regulator (7805 in not LDO) unless you don't care how long the board will last by overvolting it.

    DOV = Dropout voltage, the voltage overhead required by the regulator to operate correctly.

    LDO = Low dropout voltage, a type of regulator that requires less than a volt overhead to operate correctly.

    Is this clear to you now? Sorry the above post is terse, Im in the final hours of the fiscal quarter and quite busy.

    Post Edited (Paul Baker) : 3/21/2005 12:46:31 AM GMT
  • BeanBean Posts: 8,129
    edited 2005-03-21 01:00
    To program mine, I just connect a 5V power supply to the connectors on the battery pack with alligator clips.
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Check out· the "SX-Video Display Module"

    www.sxvm.com

    "A problem well defined, is a problem·half solved."
    ·
  • Ryan ClarkeRyan Clarke Posts: 738
    edited 2005-03-21 08:12
    thanks! I'm really enjoying my sx kit so far...

    Ryan
  • Ryan ClarkeRyan Clarke Posts: 738
    edited 2005-03-22 00:23
    My order got here today...and the medals look GREAT. I can't wait to play with them...


    Ryan
  • ForrestForrest Posts: 1,341
    edited 2005-03-22 18:08
    What is the diameter of the board?
  • BeanBean Posts: 8,129
    edited 2005-03-23 04:01
    Mine measures 2.75" in diameter. That is just the PCB.
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Check out· the "SX-Video Display Module"

    www.sxvm.com

    "A problem well defined, is a problem·half solved."
    ·
  • ForrestForrest Posts: 1,341
    edited 2005-03-23 04:43
    Great - this acrylic lens should fit well www.goldmine-elec-products.com/prodinfo.asp?number=G15340&variation=&aitem=27&mitem=36 They're also available in clear and red - though I think the red lens would make the RED LED's invisible.
  • DWinchellDWinchell Posts: 60
    edited 2005-03-23 05:42
    Hey that's COOL !!

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Thank You

    David Winchell

    David@Winchell.com
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-03-23 07:00
    It's an optical illusion (caused in the eye by persistance of vision, in the camera by the shutter timing to expose the film/ccd) -- only one column of LEDs is on at any given moment. The column-to-column switching occurs so rapidly that they all appear to be on at the same time.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Jon Williams
    Applications Engineer, Parallax
    Dallas, TX· USA
  • ForrestForrest Posts: 1,341
    edited 2005-04-03 16:09
    Parallax needs to change the descriptioin for the robolympics medal on their web site - as this description is not correct "The back of the medal has a 3 x AAA plastic battery pack, but this is only 4.5V and 6V are required for programming SX chips. " The 6V should be changed to 5V.
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