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WS2812B cable runs

wallarug

Hey,

 

I was wondering if anyone here knows any of the below relating to WS2812B LED chips?

  1. Maximum length of cable:
    1. Between the first LED and the signal source
    2. Between other pixels
  2. Best type of cable (single core/multistrand) for data signal
  3. AWG of cable.

 

Any comments would be appreciated.

 

Thank you.

  • 0

    According to this data sheet you can have upto 5m between pixels: http://www.seeedstudio.com/document/pdf/WS2812B%20Datasheet.pdf

    20 AWG wire appears to be commonly supplied with these modules.

    Single core/muti-strand appears to be a topic of personal preference.

  • 0

    There are two types of cable required for this and part of this depends on how your going to wire up the leds and how many in a strip

     

    each LED will consume about 60mA at 5V (3 leds per chip at 20mA each running from 5V supply) so 100LEDS will consume about 6 Amps if full on white, thats a lot of current to go down a single wire and you will find that the LEDS at the end will be dimmer that those at the beginning as there will be a voltage drop along the power wires so you need to break up the power distribution into smaller sets of say 30 LEDs.

     

    You can still run the data line from a single pin of the controller as each LED will buffer the data to the next LED and you can chain upto about 1000 LEDs and still get a refresh in excess of 50 times per second

     

    you do not need resistors for these as they have constant current regulators built in but it is essential that you put in the decoupling capacitors for at least every other LED if there close together or every LED if further apart. If your buying the Strips already made up then this is already done for you, just run seperate power to each strip, and daisy chain the data if you want it all from a single pin

     

    Hope this helps

  • 0 in reply to Robert Peter Oakes

    Thank you for your replies.

     

    To be a little more specific:

    • There will be 85 WS2812B LEDs
    • Each single WS2812B LED will be separated by 500 mm of cable (yes - I am cutting them up).

    So for powering them, I could run 5V:

    1. to each individual one without using the pass-through on the LED module
    2. just wire them normally using the pass-through
    3. a combination (as suggested by P.Oakes)
  • 0 in reply to wallarug

    The WS2812B chips I am looking at don't appear to have power pass-through connections. Do you have a make/model of the units you are thinking of using?

  • 0 in reply to Robert Peter Oakes

    Peter Oakes wrote:

     

    each LED will consume about 60mA at 5V (3 leds per chip at 20mA each running from 5V supply) so 100LEDS will consume about 6 Amps if full on white, thats a lot of current to go down a single wire and you will find that the LEDS at the end will be dimmer that those at the beginning as there will be a voltage drop along the power wires so you need to break up the power distribution into smaller sets of say 30 LEDs.

     

     

    Good point image