What is 2 pin SPI protocol?

[John (oldandslow)]

I decided to do a new project and bought some 12V 2811 bullet RBG.

I can't get them to work they are 3 wire - RED +,  White Data AND Blue Neg

When I hook them up only the last pixel Lights.

When I went on the site they said it uses 2 pin SPI protocol. Can I use these if so How do I hook them up to get them to work.

Thanks

John

[Mr. P]

What controller are you using? We need more info.

[John (oldandslow)]

I am using a E-682 controller. These pixels have a white and blue wire plug on each end along with a red and blue wire on each end.

I cut the plug and used the center white and the outside red and blue.

[Mr. P]

Sorry, I don't know the E682 but there are many on here who do, they should be along shortly, hang in there.

Just an fyi, you do know that data flow has to go in a certain direction, are you sure you have the flow correct?

Edited September 6, 2016 by Mr. P

[k6ccc]

The blue is ground for the data as well as power negative.  The two blue wires are tied to the same point on the pixels.   For you purposes, cut off the connectors and either tie both blue wires to the ground position on the E682 (or just cut one of the blue wires off), and then tie the red to the power on the E682, and the white to the data on the E682.  The clock output from the E682 is not used on WS2811 pixels.  Two wire SPI means that it requires a ground connection.  And as Mr. P said, make sure you are sending data towards the correct end of the string.  Look for an arrow that indicates the direction of data flow.

If this does not make sense, PM me a phone number and I'll call you.

 

[John (oldandslow)]

Thanks k6ccc, I had to put both blue wires together before they would work. I had tried each blue wire by themselves with no luck.

Your suggestion putting them together worked.

What I don't understand is that there is only 3 wires coming and going to each pixel and a extra blue on each end.

I plan on cutting the pixels in 4 and 5 pixel strips for icicles and power inject at each end. I will have two runs of 150 pixels.

I'm thinking once I have the two blues on the Ground on the controller I don't have to do anything with the extra blue on the end. Is this your thinking also.

Thanks for your help

John

[Dennis Laff]

where did you buy those 2811 pixels from?

[John (oldandslow)]

I bought them direct from China.

Edited September 8, 2016 by John (oldandslow)
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