Neopixel strips have sometimes wrong colours

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

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mouha
 
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Re: Neopixel strips have sometimes wrong colours

Post by mouha »

This is what I've always done: connecting the data (black & white to each of the individual FC outputs).
I think there is a misunderstanding : when I've asked about reversing wires I was talking about the data wires not power ones.

I did the same with all the strips : those that are good are connected the same way but for a reason I still don't understand, the 3 that have been cut (the arrow is going to the other side) doesn't light anything.

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dastels
 
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Re: Neopixel strips have sometimes wrong colours

Post by dastels »

OK, so it's the 3 half strips that you cut off from the "start" end of the original 3 that don't work?

Can I see the soldering of the wires from the FC onto those strips?

Dave

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mouha
 
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Re: Neopixel strips have sometimes wrong colours

Post by mouha »

Sure : While things are not stabilized I'm using a system that don't use soldering . So the only thing that is soldered is the wires to the FC.
And my tests were to use only these 2 wires from the same FC output each time because I've been validated them with a working strip.

To add some clarification :

FC - Data + = Tested with a working strip = tested with the 3 cut strips
- Data -

Test: connected to the FC server and sending 50% pattern from the home page
20211004_180053.jpg
20211004_180053.jpg (95.57 KiB) Viewed 155 times

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dastels
 
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Re: Neopixel strips have sometimes wrong colours

Post by dastels »

Here's the disconnect I'm having: you will have to solder to the cut ends on the 3 halves that you cut off. The 3 halves that have wiring attached to the Data-out end of the strip. The Data-in ends of those halves are where they were cut.

Dave

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mouha
 
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Re: Neopixel strips have sometimes wrong colours

Post by mouha »

dastels wrote:Here's the disconnect I'm having: you will have to solder to the cut ends on the 3 halves that you cut off. The 3 halves that have wiring attached to the Data-out end of the strip. The Data-in ends of those halves are where they were cut.

Dave
I'm sorry but I don't understand . I need to solder the end of cut strips where ?
Is there somewhere any drawing for this ?

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dastels
 
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Re: Neopixel strips have sometimes wrong colours

Post by dastels »

No drawing that i know of.

You had a strip (well, 3 of them but I'll just talk in terms on one) that had wires at each end, right? One D-in and the other D-out. That let's you connected multiple strips together. You cut them in half and now have one with wires at the D-in nd, and the other with wires at the D-out end. When you connect them to the FC you need to connect to the D-in end. You have one half-strip with wires at the D-in end, so that can be used as is. The other half-strip will need to have wires soldered to its D-in end... which is its cut end.

This guide covers the basic ideas: https://learn.adafruit.com/make-it-glow ... ners-guide.

Dave

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mouha
 
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Re: Neopixel strips have sometimes wrong colours

Post by mouha »

Oh just understood !. Didn't know that page.

the only accessible wire is D-OUt . thereofre I need to remove the plastic a little from the other cut end side and solder the D-IN from there .

The same process like with the Neomatrix

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dastels
 
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Re: Neopixel strips have sometimes wrong colours

Post by dastels »

Yes, you need to solder/connect to the Data-in end.

Dave

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mouha
 
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Re: Neopixel strips have sometimes wrong colours

Post by mouha »

It took time and patience to try and try again, soldering, fingers burning because the soldering parts are small: but 1 of the cut strips is working back.

Thanks Dave for your advices and patience. It was very important for me to find out how to make it works.

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dastels
 
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Re: Neopixel strips have sometimes wrong colours

Post by dastels »

Glad to hear it!

A key with NeoPixels and DotStars is that data flows from one pixel to another (and through each pixel) in a fixed direction.

Dave

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mouha
 
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Re: Neopixel strips have sometimes wrong colours

Post by mouha »

Actually I knew this point for the Neopixel Matrix but didn't see the consequences of data flow to the strips.

BTW: the Adafruit wiring tutorial we were talking about doesn't mention the 2 ground (black) wires, while you can see them on each side when you receive a Neopixel strip.
I suppose this is to set a common ground between the one of the FC output and the one coming from the power supply.

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dastels
 
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Re: Neopixel strips have sometimes wrong colours

Post by dastels »

You are correct. The red/black pair are a convenience for connecting an external power supply for the strip. It seems that some strips have them and some just have red, black, and white or other color for the data signal.

Dave

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