FadeCandy, NeoMatrix and WS2812

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mikeclegg123
 
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FadeCandy, NeoMatrix and WS2812

Post by mikeclegg123 »

Hello.

I am looking at a project in which the WS2812/NeoPixels and FadeCandy would work really well. I have watched your tutorial on FadeCandy it is awesome. I do have a question however. You show FadeCandy working with the NeoMatrix. However in my project, the LEDs will be apart from each other (inside glass bottles).
How can you wire individual LEDs/NeoPixels to the FadeCandy system?

Does anyone have any ideas?

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adafruit_support_mike
 
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Re: FadeCandy, NeoMatrix and WS2812

Post by adafruit_support_mike »

In general terms, you can't.

NeoPixels are made to operate in strips. Each one consumes the first 24 bits of input it sees on its DI pin and then copies everything else to its DO pin. The next pixel in the string will consume the first 24 bits of what's left and send the remainder on to the next one, and so on.

It's possible to control NeoPixels one at a time, but you'd need separate control hardware and software for each one. The FadeCandy's hardware and software can't support that.

No matter how you control the LEDs in your project, you'll need at least a VCC line, a GND line, and a data line. Wiring your pixels as a string will only add one more line, carrying data out of one bottle and into the next.

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pburgess
 
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Re: FadeCandy, NeoMatrix and WS2812

Post by pburgess »

How far apart are we talking with the bottles? And are they staying fixed in one place, or need to move?

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mikeclegg123
 
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Re: FadeCandy, NeoMatrix and WS2812

Post by mikeclegg123 »

The actual LED's, which will be in the top of the bottles, pointing downwards will all be different lengths apart. However, they will all be around 300mm-800mm apart (in length of wire between each bottle) as the bottle is hanging, the LEDs wire has to go up the support wire, across then back down the next support wire for the next bottle and so on.

I am basically needing the ability to control them all, but also fire off individual LEDs if need be.

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pburgess
 
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Re: FadeCandy, NeoMatrix and WS2812

Post by pburgess »

This sounds reasonable. Each bottle will need four wires: 5V, ground, data in and data out. Data out from one bottle will connect to data in on the next. First bottle's data in connects to the Fadecandy. (Bonus tip: use a separate cable to bear the load of the hanging bottle...don't use the power or data wires for this.)

I don't believe there's an Official Word for the maximum distance between pixels (it's dependent on many factors including wire gauge), but I've heard of folks spacing them a meter apart sometimes. You might just need to prototype and test. If the distance is too much, a trick you can use is to add extra pixel(s) in the middle of a longer span, and just always write an "off" color value to those points so they don't show.

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Re: FadeCandy, NeoMatrix and WS2812

Post by mikeclegg123 »

Excellent

Ok, so If I wanted to have say 10 different programs, and have some form of a rotary switch (or something) for the user to change between them. Would fade candy (or the controller, Raspberri Pi or something) support this? What about App control, from say an Iphone or Android?

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pburgess
 
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Re: FadeCandy, NeoMatrix and WS2812

Post by pburgess »

Fadecandy is just the messenger between the computer and NeoPixels. Any specific behavior (such as responding to a rotary switch) would be a function of the software on the computer. This could be done using the GPIO header on the Raspberry Pi. Depending on the complexity of what you want to display, an Arduino (instead of Pi + Fadecandy) might be sufficient. Some Arduino projects use the Bluefruit LE to work with iOS or Android apps.

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