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led MATRIX CURRENT DRAW

Discussion in 'Microcontrollers' started by MrDEB, Oct 4, 2012.

  1. MrDEB

    MrDEB Active Member

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    Yea right---lol
    I got to pondering the pros and cons of my design for the TX side of the equation.
    Plan was to use a 10F20 BUT! I need to use a low voltage pic and I need to check Microchip but being its an old chip it probakky not available in Low voltage. SO back to an 18f1220 or smaller (need to look at footprints but probably nothing available w/ <18 pins smd.
    You have to excuse me as I just woke up (pondering voltage vers footprint so I have yet to research. If i go with the 18VF pic then Swordfish is available but I found a Manchester code that would need to be revamped. Lots of options.
    As far as the Matrix, I plan to run the LEDs at 20-22ma for battery issues.
    LOML brough my morning coffee and our dog Tasha is staring at me for attention so off I go.
     
  2. be80be

    be80be Well-Known Member

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    MrDeb I'm only going to say this once you can run most any pic chip in low voltage just don't use the fastest crystal speed. But at 3 volts and 4mhz you'll not have any problems even if you used a 18f1230 it will be happy at 4mhz and 3 volts
     
  3. MrDEB

    MrDEB Active Member

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    I was referring to the K series (looked at Microchip sight) the 18F13K22 is 1.8v - 5.5v.
    This wide of range will hopefully allow for battery drainage etc. Have to look at the transmitter chip but I believe it was 3v min. Looks like the K series is cheaper as well but the 18F13K22 I think was in a 20 pin soic??. Need to do more research etc. But this is where I am headed.
    Sorry if I failed to use the correct type of PIC.
     
  4. dave

    Dave New Member

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  5. JonSea

    JonSea Well-Known Member

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    Well, lets assume you mean a PIC10F200, since there's not 10F20 part. Why do you assume it's an "old part" and the 18F1320 is somehow a "new part"?

    The PIC18F series was introduced in the year 2000 according to Wikipedia. The PIC10F20x series was introduced in 2004 specifically to address the need for lower pin count devices and lower cost devices in battery powered products.

    This illustration below is from a Microchip presentation on the PIC10F20x series. The PIC10F20x works down to 2 volts.

    View attachment 68212

    But, disregarding your erroneous assumption, what language would you use to program a 10F200? Swordfish isn't going to work.
     
  6. JonSea

    JonSea Well-Known Member

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    Huh? You say "18f1220" and somehow people are supposed to know you really mean an 18F13K22?

    Why don't you try doing your research first so as to not waste peoples' time? Totally new concept I know.
     
  7. MrDEB

    MrDEB Active Member

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    I realize Swordfish isn't going to work. I have two examples of code one in C and one in Basic Pro. Am pondering several different avenues. Either a K series pic or the smaller 10F200 pic. They both have pros and cons. I need to dig out the data sheet for the TX/RX modules to determine voltage requirements. IF the voltage requirement is 2v or less then go with the K series (they are cheaper, at least comparing to other similar.
    I don't need too much ram but my original idea was to use a 7555 timer. This is doable as well. Reliability may be another issue. Am trolling my ideas. Three or more opinions are better than one.
    One issue with the 7555 is programming the RX/PIC section to interpret the pulse train. Say a 1hz train = switch one. A 2hz train = switch two. Am just mulling over ideas.
    IF you read my post you will see I NEVER mentioned that I could use Swordfish on any PIC other than an 18 series PIC. Re-READ post #141 VERY SLOWLY
     
  8. JonSea

    JonSea Well-Known Member

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    I have an even better idea. You should try learning how to use one language before trying your copy&paste(tm) programming technique in yet another language. 3000+ posts here is good testimony that it's not really been successful for you.

    Furthermore, there will be no "furthermores" from me. Good luck and infinite patience to those few who still try to help you.
     
    Last edited: Oct 21, 2012
  9. MrDEB

    MrDEB Active Member

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    Well maybe we got rid of him.
    He has been some help but as far as people skills = 0
    I should have gotten him banned again from Electro tech(see post #99). Surprised he wasn't banded using four letter words that no self respecting sailor would use. I gave him the benefit of the doubt thinking maybe he has changed his ways.
    and YES I do copy n paste but then I rework it to fit my needs.
    Mrdebsnightmare or Jonsea needs to learn how to ask and decipher different opnions. YES I ask for suggestions but Iat least I read the suggestions and comments. Lets see, I mentioned that I am using a 5 x 7 matrix block by Kingbright about 10 times but Jonsea or Mrdebs nightmare still insists I use individual LEDs. I mentioned numerous times I found I had some bad LCDs but Jon had different ideas of my issues.
    In my LED matrix design I followed his "bosses" schematic over at DDIY but found it was not right as the resistors were on the anodes not the cathodes. No mention of this mistake.
    I brought to Jonseas or Mrdebsnightmares attention but fell on def ears or eyes seeing how he doesn't bother to realize that other people see his mistakes or lack of social skills. And people wonder why DDIY has so few posters. My last count of active posts I could count on my fingers on one hand.
    I guess Jon misses me over at DDIY so he came over here to rattle my cage. ---lol
    I must apologize for this rant but I just had to.
     
  10. JonSea

    JonSea Well-Known Member

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    I'm glad you appreciate all the help I've tried to give you MrDEB, Many posts, a number of articles, hundreds of illustrations and you've learned....well, in approximate terms, nothing. Fortunately, many others have benefited from the simple level of advice given.

    Good luck.
     
  11. MrDEB

    MrDEB Active Member

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    I have learned a lot from your advice and suggestions. Have tried ALL your suggestions except the separate LEDs for the matrix.
    In case you haven't read all my posts I have thanked you numerous times.
     
  12. MrDEB

    MrDEB Active Member

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    Well I had to experiment with the TLC5916/17 using this
    http://www.electro-tech-online.com/custompdfs/2012/10/slvs695c.pdf
    Have Vcc at 4v, two LEDs on pins 6 & 8
    with one LED (measured the current draw to the LED itself) at 69.5ma!! two in parallel = 139.2ma
    BUT with this much current the LED still works!!
    WHY?
    Maybe because the LED is blinking at a 10khz rate?
    I have a 270 ohm resistor pin 15(r-EXT to ground. Contemplating changing to see just how bright I can get the LEDs.. I assume this is what Mike was talking about with duty cycle?
    This chip could be of use for my LED matrix project?
     
  13. be80be

    be80be Well-Known Member

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    What your saying sounds right these can handle 100mA brust
     
    Last edited: Oct 23, 2012
  14. MrDEB

    MrDEB Active Member

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    BUT using a high current burst, would that not drain the battery faster BUT allow a brighter LED?
    Got the TX module sorted out, BUT I was testing my Matrix code by running all three sub routines , one after the other. BAM!! the RED LEDS come on when the sub routine does not call for them.
    This is after the code runs through the three subroutines onece then the green gets mixed with the Red. Thinking that I need to reset the port regeisters or ?.
    Tried pitting portc = 0 etc at the start of each routine but to no avail. Going to try different things.
     
  15. MrDEB

    MrDEB Active Member

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    problem of "routine carry over solved"
    just added a delayms(1000) after the next statement.
    WHY it worked??
    thinking the code just flowed without a time lapse or ??
    IT WORKS
     
  16. MrDEB

    MrDEB Active Member

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    • Like Like x 1
  17. be80be

    be80be Well-Known Member

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    That looks nice
     
  18. MrDEB

    MrDEB Active Member

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    THANKS
    after I get the TX/RX and interrupt working I hopefully will have the brighter LED matrix in hand then look at increasing the current draw per LED. Looking at 20 - 23ma.
    Thought about a fast scan after I see what the 10khz blink does but this might waste power??
    Need to research.
     
  19. be80be

    be80be Well-Known Member

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    Test the power used from the supply to get best total used
     
  20. MrDEB

    MrDEB Active Member

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    Am powering the PIC off the PICKIT2 and an 8v battery. So far the measurements have been just for the LEDs only.
    Going to fiddle with the matrix seeing just how much brighter it looks with a burst of 80ma vers constant 20ma.
    BUT thats after I figure out the swordfish manchester TX/RX stuff.
     
  21. be80be

    be80be Well-Known Member

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