rgb led driver

Discussion in 'General Electronics Chat' started by mentaaal, Jun 10, 2007.

  1. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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    hey guys, i was wandering if any of you clever fellows could be kind enough to post me a schematic to drive an rgb led. I dont know if these differ but mine has six pins, i'm assuming two each for each individual led inside. what i want it to make the led change colours constantly on its own. I dont really know how to do this but i am guessing it has something to do with varying the current on each colour and vary it randomly? My initial thought was to use potentiometers to at least get the thing to work but if i could automate this process it would be great. I am assuming this is going to require some kind of an ic?

    Thanks loads in advance!
     
  2. hgmjr

    Moderator

    Jan 28, 2005
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    Are you interested in a solution that involves a microcontroller or do you want to use a non-micro approach?

    hgmjr
     
  3. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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    well its a complete learning experience. so i guess the easiest first- non micro controller? i dont have a programmer either. then i will move onto something more difficult.

    cheers!
     
  4. hgmjr

    Moderator

    Jan 28, 2005
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    I did a bit of googling and was not successful finding an existing solution that did not involve a microcontroller.

    There are ways to manipulate the colors of an RGB LED without the use of a micro but it is a bit more effort to produce such a circuit. There may be other forum members who have already designed such circuitry. I myself have not.

    Are you interested in learning to design with as well as program microcontrollers or is that more than you wish to tackle at this point in time?

    hgmjr
     
  5. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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    I'll tackle anything! I am about to go start a batchelor of engineering degree course in september so i really have the spirit to do all of this now. so i best get something done before i lose it :)

    yeah sure. i'll have to order the necessary parts from maplin but they really do rock for fast delivery!

    and thanks for your help and your quick reply
     
  6. hgmjr

    Moderator

    Jan 28, 2005
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    Do you have any programming experience? Assembly Language, C-language, BASIC, FORTRAN, etc.

    Is $100 US dollars an uncomfortable amount of money to spend on a development board, a power supply and the programming software? Are you familiar with DigiKey as a source of electronic components and such?

    hgmjr
     
  7. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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    afraid not... no programming experience worth speaking of. i have accumulated some stuff partly for my course and my own interests. i have a power supply, and the basics, but not much else really. but i was thinking i'm going to have to invest in a pic programmer at some stage and learn it so now is a good time i guess. perhaps i could just download the source code from someone who has done this before. i didnt think that it would be this difficult to be honest but i am willing to give it a shot

    thanks
     
  8. hgmjr

    Moderator

    Jan 28, 2005
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    You mentioned PIC and that's one option. Another option to consider is the AVR series of microcontrollers from www.atmel.com.

    Without spending a single cent or pence in your case you can right now go to ATMEL's website and download the free (yes I said free) AVRSTUDIO4 software and be learning to program in assembly language almost immediately. You can go to www.avrbeginners.net and study the examples provided to get very good basic understanding of the AVR series. You can go to www.avrfreaks.net to find an online community that can provide all sorts of support for the AVR enthusiast.

    AVRSTUDIO4 runs on WINDOWS PCs and is a powerful software development tool. It has the abilitity to single step through the program and provide a virtual control panel that shows you what is happening in the virtual AVR processor without the need for hardware.

    Just google on AVR projects and you will see that there are tons of interesting projects on the Internet.

    hgmjr
     
  9. Papabravo

    Expert

    Feb 24, 2006
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    Who makes the 6 lead LED? The only ones I could find had only 4 leads.
     
  10. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    If you want to make one that does not involve microcontrollers, take a look at Bill Bowden's Fading Red Eyes. If you build 3 of these (you can use one LED in each circuit instead of two), and use different values for the capacitor in each circuit, you should get random colors. Actually, if you use the same value in all three, component tolerances should still yield random colors, although the changes might be really slow.
    With 3 oscillators running off the same power supply, you will need really good power supply decoupling, like 100uF in parallel with 100nF across the 9V supply, or you might get injection locking between the oscillators. In fact, you might still get injection locking.:(
     
  11. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
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  12. Papabravo

    Expert

    Feb 24, 2006
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    OK - so Maplin is the distributor, but the manufacturer is Kingbright. That is where the full datasheet and any application notes may be found. Thank you masked man!

    The date on the datasheet supplied by Maplin is July 2002. Yet I had no luck finding the datsheet on the Kinbright website. I would be careful about using a product which may have gone away. FYI - The colors listed are BLUE/HYPER ORANGE/GREEN
     
  13. hgmjr

    Moderator

    Jan 28, 2005
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    I was able to score a datasheet for the rgb LED KAF-5060PBESEEVGC. You will need to scroll down on the webpage to find the link but it appears to be the correct one.

    Hopefully it will be useful.

    hgmjr
     
  14. cumesoftware

    Senior Member

    Apr 27, 2007
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  15. Papabravo

    Expert

    Feb 24, 2006
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    None of your links was to the appropriate part. The subject part looksw like a small six pin DIP. The main site www.kingbright.com display nothing but a box with a Red X
     
  16. Papabravo

    Expert

    Feb 24, 2006
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    I got the datasheet from the Maplin site. That was not the issue. The question is why is the main Kingbright site apparently broken. Second questions is why the US site chokes on the part number as if it didn't exist? I can think of only two reasons:
    1. Product is not available in the US
    2. Product has been discontinued.
    There may be others. Pretty strange behavior for a manufacturer.

    EDIT: Got the following email from Kingbright
    Hi ......,

    Currently only about 25% of our production line is on our web site. KAF-5060PBSEEVGC is a valid part number and current lead time is 5-6 weeks. You will be able to purchase this part from any one of our authorized distributor.

    Should you have any questions, please let us know. Thank you!



    L..... H......
    Kingbright Corporation
    www.us.kingbright.com

    I sure hope it is the 25% with the best sales!​

     
  17. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    Well, it seems seem to work fine in other computers than mine. I am now using one of the university computers. Also, aren't we looking for full color LED's (red, green and blue)? Of course these are 4 lead LEDs, but are the most used type.

    For full color SMD LED (Europe and Japan): http://www.kingbright.com/product_m...4115206&product02=20050530015744&lang=English
    You should see a big table, which you have to scroll down.
    For full color SMD LED (US): http://www.us.kingbright.com/category.asp?catalog_name=LED&category_name=SMD Full-color/RGB&page=1

    It is better than using a googlefinger (or a macdonaldfinger for those who have).
     
  18. hgmjr

    Moderator

    Jan 28, 2005
    9,030
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    Greetings mentaaal,

    Are you planning to use this LED in a production design or is this just a exercise in learning more about how to interface to RBG LEDs?

    I seem to be able to access www.kingbright.com without a problem.

    hgmjr
     
  19. Papabravo

    Expert

    Feb 24, 2006
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    I tried your link, but no cigar. I may try cycling my router and cable modem. I've noticed problems in the past going to some websites. It is as if they just got routend to nowhere by the DNS cache.
     
  20. mentaaal

    Thread Starter Senior Member

    Oct 17, 2005
    451
    0
    i have to say i am impressed with all the effort you guys are going to for this thread. Well its not a really big deal i am not using this led for anything important really. i remember seeing a project where someone took an led like this one and stuck it underneath a kind of frosted vase and used it as a kind of ornamental piece. so i was thinking if i could get it to change colours nicely perhaps i would try to do the same as the project.

    but it really is just as a learning experience. When i get some more parts i will try it.

    thanks alot again
     
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