LedStrip.py

# Simple Python Library for accessing WS2801 LED stripes
# Copyright (C) 2013  Philipp Tiefenbacher <wizards23@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# For more information about this project please visit:
# http://www.hackerspaceshop.com/ledstrips/raspberrypi-ws2801.html

class LedStrip(object):
    def __init__(self, nLeds, nBuffers=1):
        self.nLeds = nLeds
        self.nBuffers = nBuffers
        self.buffers = []
        for i in range(0, nBuffers):
            ba = bytearray()
            for l in range(0, nLeds):
                ba.extend([0,0,0])
            self.buffers.append(ba)

    def close(self):
        ""
    def update(self, bufferNr=0):
        ""
    def setAll(self, color, bufferNr=0):
        for i in range(0, self.nLeds):
            self.setPixel(i, color, bufferNr)

    def setPixel(self, index, color, bufferNr=0):
        self.buffers[bufferNr][index*3:index*3+3] = (color[0], color[2], color[1])

    def getPixel(self, index, bufferNr=0):
        return [self.buffers[bufferNr][index*3],
                self.buffers[bufferNr][index*3+2],
                self.buffers[bufferNr][index*3+1]]

class LedStrip_Dummy(LedStrip):
    def __init__(self, nLeds, nBuffers=1):
        super(LedStrip_Dummy, self).__init__(nLeds, nBuffers)

class LedStrip_WS2801(LedStrip):
    def __init__(self, spiDevice, nLeds, nBuffers=1):
        self.f = open(spiDevice, "w")
        super(LedStrip_WS2801, self).__init__(nLeds, nBuffers)

    def close(self):
        if (self.f != None):
            self.f.close()
            self.f = None

    def update(self, bufferNr=0):
        self.f.write(self.buffers[bufferNr])
        self.f.flush()