Beagle Bone & NeoPixels

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
CrabbyPete
 
Posts: 16
Joined: Fri Nov 07, 2014 9:13 pm

Beagle Bone & NeoPixels

Post by CrabbyPete »

I see there is a library for Arduino for the NeoPixel will it work with a Beagle Bone Back board?

User avatar
adafruit_support_mike
 
Posts: 67454
Joined: Thu Feb 11, 2010 2:51 pm

Re: Beagle Bone & NeoPixels

Post by adafruit_support_mike »

Nope.

Linux machines like the RasPi and BBB don't handle NeoPixels very well.

The trouble is that those kinds of machines use a 'time slicing' operating system model: each process gets a certain amount of time on the CPU (usually 10ms) then the OS suspends it, swaps in the next process, and gives that one a turn.

That's great for basic number-crunching and human-interface work (the OS can swap half a dozen processes in and out between the moment your finger hits a key and the moment the keyboard registers a keypress) but it causes problems when you want to talk to other hardware.. especially hadware whose signals are time-critical like the NeoPixel's.

The pulses in a NeoPixel signal train have to be timed to within about 10ns, and the strip sees a gap of 50 microseconds as a signal to end that set of commands and start a new one. A time-slicing OS swapping the process generating those signals out for a significant fraction of a second would have about the same effect as a pilediver on a game of Operation.

The usual solution for such jobs is to use an Arduino (or similar single-task microcontroller) as a driver for the NeoPixel strip, and let the BBB or RasPi do the heavy thinking. You can arrange a UART connection between the BBB/RasPi and the microcontroller that isn't timing critical, but feeds the microcontroller the information it needs to keep the strip going.

User avatar
pburgess
 
Posts: 4161
Joined: Sun Oct 26, 2008 2:29 am

Re: Beagle Bone & NeoPixels

Post by pburgess »

Update: have a look at Trammell Hudson's LEDscape.
https://trmm.net/LEDscape

Locked
Please be positive and constructive with your questions and comments.

Return to “Beagle Bone & Adafruit Beagle Bone products”