Help with making LED Sign

Discussion in 'The Projects Forum' started by R41, Jun 24, 2014.

  1. R41

    Thread Starter New Member

    Jun 24, 2014
    3
    0
    Hello

    Not sure if this is the place to ask for help.

    Have been trying to make an led sign light up
    using ws2801 led strip.

    Anyone know anything about these?

    Any help would be greatly appreciated

    Thank You

    R41

    The strips have 1 ws2801 chip for every 3 led.
    The first 3 led light up but then do nothing. I have tried switching the clock
    and data wires, read online that they sometimes they are mislabeled from the manufacturer.
    but still wont work.
    I have made sure they are connect on the input side as well.

    When I connect the clock and data wires together on the input one whole strip lights up
    then the next does not, and on the 3rd strip the first 3 led light up.

    Helllllpppp Please...
     
    Last edited: Jun 24, 2014
  2. R41

    Thread Starter New Member

    Jun 24, 2014
    3
    0
    Is this an LED to mains?

    Sorry if it is.
     
  3. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,393
    497
    It is not designed for mains.

    Reading the datasheet, it seems you need to keep sending the data until each chip in the strip receives the data.

    Let us examine your example. You sent the data, first chip received the data, this first chip controls first three led on the strip, so the chip lighted up the three led that it controls. You say that the next three led did not light up. This tells me that you only sent one "packet" of data. To light up second set of three led you need to send "packet" of data to the second chip.
    So.
    To light up first 3 led you sent 24 bits to the first chip.
    To light up first 6 led you send 24 bits to the first chip, 24 bits to the second chip.
    To light up first 9 led you send 24 bits to the first chip, 24 bits to the second chip, 24 bits to the third chip.
    It looks to me, from programming point of view, that you need a for loop, you know exactly how long your strip is, you know exactly how many chips are on the strip. Lets say you have 6 chips (6x3=18 led):
    Code ( (Unknown Language)):
    1.  
    2. int chip;
    3. [some code to turn on the clock]
    4. for(chip=1, chip=6, chip++)
    5. {
    6.   [some code to send 24 bits that select color]
    7. }
    8.  
     
    Last edited: Jun 24, 2014
  4. R41

    Thread Starter New Member

    Jun 24, 2014
    3
    0
    Hello Thanks for the reply.

    I am using a control called T1000 uses an sd card, the program to make the lights work
    is made with a program called lededit.

    I can get a whole strip to light up that is 33 leds and they run the program from the controller.

    They only light up when I connect the data wire to the clock wire.
    which should not be the case.
    it is then suppose to continue to the next strip of 33 leds. and then the third strip.
    however the 2nd does not light up at all, and on the 3rd only the first 3 led light up
    but do not light up the way they are suppose too.

    The set up is the one in this diagram.

    https://drive.google.com/folderview?id=0B-Ouu5nPnfiBSzVIRHZmZ1JLVGc&usp=sharing

    everything is connected that way, but still not working. I am using the 12v ones and not the 5v.

    from what I have read they should work the same.

    Not sure what do to now, Thought it could be the controller so I tried
    an arduino uno board and get the same results. then I check all the leds
    to make sure they all turn on and they do.

    The T1000 sends the data and clock , but only seem to work on the first strip the
    way it should.

    Never thought this would be so frustrating. lol
    thanks for looking
     
  5. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,393
    497
    "The Connection and Driving of Cascading Operation
    The transmit the data over long distance by cascading, the
    WS2801 integrates push-pull out
    put stage with strong driving
    capability which enables the data and clock can be transmitted up to 6 meters at 2MHz clock frequency.
    To prevent the reflection, it is necessary to connect a 50

    resistor at the data input or
    output port for impedance match.
    "

    I think you should try this.
     
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