twp / pixelbot

Tasty integration of neopixels and web services

What is this?

A small ruby web service for controlling NeoPixels attached to a RaspberryPi.

Is it any good?

Yes.

How do I run it?

Clone the repository to your RaspberryPi, and install all the dependencies:

git clone https://github.com/TwP/pixelbot.git
cd pixelbot
script/bootstrap

Open the pixelbot.yml file in your favorite editor and set the number of leds to the number of NeoPixels you have connected to your RaspberryPi. Set the gpio pin number to match the GPIO pin where the NeoPixels are connected to your RaspberryPi. Please read the RaspberryPi NeoPixel guide from Adafruit for all the details on setting up your NeoPixel circuit.

To start the web service run:

sudo script/pixelbot

Enjoy the blinkenlights!

It won't run!

Yes it will.

The ws2811 driver is using direct memory addressing (DMA) via /dev/mem to control the NeoPixels. Only the root user has permission to read and write to this hardware device. So any time your work with NeoPixels, your code will need to be run as the super user.

But I don't have a RaspberryPi

You're in luck!

When running on an architecture other than linux-arm (the RaspberryPi architecture), a fake LEDs class is used to simulate the NeoPixels. This set of fake LEDs is provided by the pixel_pi gem, and the fake LEDs are automatically used where needed.

The fake LEDs are displayed in the terminal using a UTF-8 fisheye "◉" character, and the fake LEDs are colorized using the rainbow gem. So you can work with the LEDs even when a RaspberryPi is not handy.