Why two grounds for WS2811s?

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  • I plan on running many strings of WS2811 chipped LEDs. A power supply will power the espruino, and the strings. The data-out of one string will feed into the data-in of another string. The strings of WS2811 commonly available have two ground wires coming out of each end. One of the grounds is mated with the data wire (see pic). I plan on using one of the grounds for each power injection, do I need to use the other ground for the data linking?

    FYI: I'm cutting off the black connector that came on the strings and replacing with a waterproof connector. If I don't a ground with the data, then I'll just use a single pin connector for data.

    Here is my plan. Does it look OK, or is it flawed?

  • Do you have a datasheet or product description of the actual string of WS2811s that you are planning on using?

  • No data sheet, but if it helps, here is an auction selling the same string I have: http://www.ebay.com/itm/272035558302

  • I'd say definitely connect ground on the strings together as well. They'll be reading data from the voltage between GND and Data wires - so if GND can be at different voltage in each string (which is possible because of the current draw) then they may not work correctly.

  • It looks to me like the grounds are connected within the string - and it's just for convenience that they have one paired with the data in (since the controller needs to be connected to GND and data in), and one paired with the power (since the power supply, which is probably a separate piece of hardware, will need to be connected to ground and power)

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Why two grounds for WS2811s?

Posted by Avatar for dbkingsb @dbkingsb

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