Raspberry Pi with WS2812b strips

I have been looking into the feasibility of this too, I already have several Arduino custom solution running WS2811/2B LEDs, some on custom boards and some using the 60 LEDs per strip stuff. the issue you will find is that the PI can not guarantee maintaining the required 800Khz data rate reliably (A common issue with micro-processors running a multitasking OS like Linux, windows or other os), If you where to do this you will probably need to use C and directly interact with the hardware GPIO and may not be able to get more than a few LEDs working because of the above mentioned issue

What most people are doing in this space is to have an Arduino (ATMega ) or other Micro-controller do the refreshing of the LEDS and have the PI instructing the controller what pattern it requires. All the clasic micro-controllers have SPI or I2C support (TI MSP430, ATMEL ATMEGA etc) and are easy to interface to. by nature the micro-controllers are much more reliable at this kind of task (From a timing perspective)

A good platform to learn this technology and with the added benefit of learning distributed automation (More than one cpu in the system co-operating to perform a task) would be to get a Gertduino board from Element 14 ( http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/gertduino ), they are currently under review in the Road tests and there is plenty of information on how to use them. The AdaFruit Arduino libraries are the best I have found for driving the LED chips and I have tried quite a few) you can find the library here ( http://learn.adafruit.com/adafruit-neopixel-uberguide/arduino-library )

The issue with the Micro-Controllers is typically how much memory or lack there of and so if you get them to do too much thinking vs simply running the lights then you will run into problems. Have the PI or PC do the thinking and simply upload the patterns to the controller and you'll be able to do amazing things

If you need to know more, please let me know, ill see about digging out my code and stuff to share on the forum

Peter

I have been looking into the feasibility of this too, I already have several Arduino custom solution running WS2811/2B LEDs, some on custom boards and some using the 60 LEDs per strip stuff. the issue you will find is that the PI can not guarantee maintaining the required 800Khz data rate reliably (A common issue with micro-processors running a multitasking OS like Linux, windows or other os), If you where to do this you will probably need to use C and directly interact with the hardware GPIO and may not be able to get more than a few LEDs working because of the above mentioned issue

What most people are doing in this space is to have an Arduino (ATMega ) or other Micro-controller do the refreshing of the LEDS and have the PI instructing the controller what pattern it requires. All the clasic micro-controllers have SPI or I2C support (TI MSP430, ATMEL ATMEGA etc) and are easy to interface to. by nature the micro-controllers are much more reliable at this kind of task (From a timing perspective)

A good platform to learn this technology and with the added benefit of learning distributed automation (More than one cpu in the system co-operating to perform a task) would be to get a Gertduino board from Element 14 ( http://www.element14.com/community/community/raspberry-pi/raspberry-pi-accessories/gertduino ), they are currently under review in the Road tests and there is plenty of information on how to use them. The AdaFruit Arduino libraries are the best I have found for driving the LED chips and I have tried quite a few) you can find the library here ( http://learn.adafruit.com/adafruit-neopixel-uberguide/arduino-library )

The issue with the Micro-Controllers is typically how much memory or lack there of and so if you get them to do too much thinking vs simply running the lights then you will run into problems. Have the PI or PC do the thinking and simply upload the patterns to the controller and you'll be able to do amazing things

If you need to know more, please let me know, ill see about digging out my code and stuff to share on the forum

Peter

At 54kbytes per "frame" the arduino-like processors are quite quickly "too small" for the intended number of leds. I think an STM32F4xx microcontroller has the DMA-capabilities to handle a significant number of led-chains in parallel. If I remember the specs correctly I'd say up to about 20kbytes of video-data per chip would be doable (you'd need to expand the raw video data to three bits-per-bit to allow the DMA engine to do its work (i.e. provide accurate timing) while the CPU does other things like expand the video data from one bit-per-bit to three bits-per-bit.)

But with $7500 in led strips it sounds like an interesting project with a larger budget than what I have available for my projects... :-)