Hello, Looking for some guidance on to program parallel led strips Instead of having

Blacken_Blue · August 11, 2018, 11:32pm

Hello,

Looking for some guidance on to program parallel led strips

Instead of having a single long line of leds, looking to have multiple branches
, they either criss cross or double back etc,

Hence instead if a making a light travel down a “path” on one led strip, It need to travel down multiple branches, and at times step over parts of a branch

Any suggestions on methods to approach this?

Cheers

marmil · August 12, 2018, 4:02am

Do you want them doing the same thing, or each one with it’s own unique pattern?
Is each one connected to a separate data pin?

Can you share a sketch of the layout for clarity?

Did you see these FastLED examples?

Blacken_Blue · August 12, 2018, 8:43am

@marmil

Hello Marc, Thanks for the links. Ill look to learn from them (I think I have a fair amount of catchup . )

Below sketch might assist. 1st diagram is complete layout. 2nd is it broken into two branches so no overlap. 3rd illustrates segments between joints.

Movement may travel across branches, or different segments in same branch.

For example B --> E --> A --> D

Ideally would like to make it so point travels along a segment, and then chooses the next segment randomly according to whats available (and then repeat travel / choose segment path etc )

For example when traveling form A --> D, the available choices for next segment are either E or C

Cheers

marmil · August 12, 2018, 9:07am

That’s an interesting coding challenge. I think you can wire everything up as just a few (two?) strings because it’s all going to get sorted out/routed in code, so make the wiring as easy for you as possible.

How many pixels are you thinking?
How long is a side, say A to B?

I feel like I saw this sort of thing before (pattern moving up to a joint and then randomly going one way or the other) but can’t remember if it was by someone here or I saw it elsewhere. It looked really cool though. @Andrew_Tuline do you remember this sort of a display? It was in an infinity cube or dodecahedron or something.

marmil · August 12, 2018, 9:09am

Haha, or maybe it /was/ Andrew that shared it.

Blacken_Blue · August 12, 2018, 12:27pm

@marmil Was thinking about 16 pixels per segment

marmil · August 12, 2018, 3:24pm

Because it’s a fairly small number of pixels overall, mapping the whole thing might be an option to consider.

Here’s a page to initially help lay things out and explain the concept.
https://macetech.github.io/FastLED-XY-Map-Generator/

github.com

macetech/RGBShades/blob/master/XYmap.h

// Helper functions for a two-dimensional XY matrix of pixels.
// Special credit to Mark Kriegsman
//
// 2014-10-18 - Special version for RGB Shades Kickstarter
//              https://www.kickstarter.com/projects/macetech/rgb-led-shades
//              2014-10-18 - code version 2c (local table, holes are r/w), 
//              by Mark Kriegsman 
//
//              This special 'XY' code lets you program the RGB Shades
//              as a plain 16x5 matrix.  
//
//              Writing to and reading from the 'holes' in the layout is 
//              also allowed; holes retain their data, it's just not displayed.
//
//              You can also test to see if you're on or off the layout
//              like this
//                if( XY(x,y) > LAST_VISIBLE_LED ) { ...off the layout...}
//
//              X and Y bounds checking is also included, so it is safe
//              to just do this without checking x or y in your code:

This file has been truncated. show original

Another example

And an alternate form of mapping where only the x,y coordinate of a pixel is put into an array.

Or you might come up with your own tricky way to route things around your layout. Like I mentioned though, however you physically lay it out and wire it shouldn’t really matter. All the trickiness will be done in code.

Blacken_Blue · August 13, 2018, 10:00am

@marmil Thank very much for the links - very useful. Any pointers
for process overviews when doing 3d arrays?

Have run across various stories in #d Cubes etc - the tricky part is sorting the wheat from the Chaff…

Cheers