Is there any straight forward way to say take a strip of 40 led and make it so it’s two strips? 20 and 20?
Do you mean you want to represent your single LED strip as two strips in FastLED? If so, then take a look at CRGBSet. This is a good gist to get you started: https://gist.github.com/chemdoc77/80ab638588399c9a09e26a296d56f6e6
https://gist.github.com/chemdoc77/80ab638588399c9a09e26a296d56f6e6
Can you explain a bit more about what you’re wanting to do?
I cut the strips in the middle so I’ll have a 20 and 20. I can then either hook them together in a serpentine fashion, usually in a ‘Y’ pattern for my projects or, if they’re WS2812’s, hook up up to separate pins. All depends on what I have and what I want to do.
So, it’s for a costume, trying not to have wires from the board all over the place. Already mirrored this strip once and read it can mess up if you do 4 off the same data. Here’s what i have for this strip only(there’s 4 other sets of lights) and was trying to achieve this on this one so I could have the same effect on all 4 at once.
The problem with that layout is that you’re connecting Data Out on strips 1 and 3 to Data Out on strips 2 and 4, respectively (with strips numbered from top to bottom).
You need to either reverse the direction of strips 2 and 4 and account for that in your code, or you need to run the data line back to the first LED in strips 2 and 4.
@Chris_Parton That’s why I was hoping to split strips without making wiring more complex, cause there is a ‘reverse direction’ that’s pretty easy to do.
@Matt12
As @Chris_Parton said you ‘reverse’ the direction of strip 3 and 4 so the data out goes in the data in.
Then in your code if you want to replicate the content of strip 1 in strip 2
Inum_leds represent your total number of leds (40 in your case)
leds[] is thebarray with all you leds
First populate your pattern of the first strip
Then
For (int i=0;i<num_leds/2;i++)
leds[num_leds-i-1]=leds[i];
This will copy the pattern to the second strip
And if you have 4 strips
Plug them all together in a snake pattern
It will look
—->
<—-
—->
<—-
This way only one data wire from your mcu to the strips
Then adapt the code above
int strip_length=num_leds/4; //here num_leds=80 for your case
for(int i=0;i<strip_length<i++)
{
leds[2strip_length-i-1]=leds[i];
leds[2strip_length+i ]=leds[i];
leds[4*strip_length-1-i]=leds[i];
}
This will copy the pattern of the first strip to all the other strips.
@Yves_BAZIN @Chris_Parton Just to clarify, I’m not connecting to the Data Out, I’m just running the strips reverse.(Intended to reverse pattern on those)
@Matt12 I meant you do not need to have two data pins.
Red =5v $
black=GND
Green =Data line
the code i gave you will duplicate the data of the first strip to all the other strips taking also into account the strips which are reversed
missing/deleted image from Google+
@Yves_BAZIN Ahh I gotcha.Well I was thinking it’d be hard enough to do 1 reverse in a strip let alone a back and forth… I’ll give that a shot!
Hello @Matt12 let me know if it works ( normally it should).
I made a typo
It’s for(int i=0;i<strip_length;i++) of course 
I assume this would work for different lengths as well?
Might make the code just a bit more complicated, but yes.
@Matt12
If each strip are of different lengths as @marmil said ,it will be a bit more complicated but feasible.
@Yves_BAZIN So, related to the last question(different project). I am messing with the Fire2012 demo and trying to take one strand of led(single data) and split it into 3 fires. I split the numbers(they aren’t equal) for 3 functions but it doesn’t work. Is that because I can’t assign the colors to the leds like that?
@Matt12 like that I can’t say really.
- could you post your code on gist ?
- what do you mean by ‘split’ ?
- did the code I gave you worked?