• raspberry PI
• WS2801 LEDs (http://www.ebay.de/sch/?_nkw=WS2801%20RGB%20LED)
• stärkeres 5V Netzteil (je nach Anzahl der LEDs 2-4 Watt)

import httplib2 as http
import json
from pprint import pprint
import argparse
import csv
import socket
import time

try:
    from urlparse import urlparse
except ImportError:
    from urllib.parse import urlparse

headers = {
    'Accept': 'application/json',
    'Content-Type': 'application/json; charset=UTF-8'
}

targetELW =     urlparse('http://sqlserver/middleware.php/data/f2059450-bbbe-11e3-aabc-7bfab5f4b02e.json?from=now')
targetHeizung = urlparse('http://sqlserver/middleware.php/data/26bce7c0-bbc2-11e3-b634-3334d2c934ae.json?from=now')
targetHaus =    urlparse('http://sqlserver/middleware.php/data/32e8d3d0-bbc2-11e3-8f42-eb76d7115f4b.json?from=now')
targetPV =      urlparse('http://sqlserver/middleware.php/data/4186f3e0-bbc2-11e3-a87a-8b10388c97ce.json?from=now')
gamma = bytearray(256)
spi_dev_name = '/dev/spidev0.0'
PIXEL_SIZE = 3
SCALE = 500
BLACK = bytearray(b'\x00\x00\x00')
BLUE = bytearray(b'\x00\x00\xff')
CYAN = bytearray(b'\x00\xff\xff')
FUCHSIA = bytearray(b'\xff\x00\xff')
GREEN = bytearray(b'\x00\xff\x00')
RED = bytearray(b'\xff\x00\x00')
WHITE = bytearray(b'\xff\xff\xff')
YELLOW = bytearray(b'\xff\xff\x00')

# Apply Gamma Correction and RGB / GRB reordering
# Optionally perform brightness adjustment
def filter_pixel(input_pixel, brightness):
    output_pixel = bytearray(PIXEL_SIZE)
    input_pixel[0] = int(brightness * input_pixel[0])
    input_pixel[1] = int(brightness * input_pixel[1])
    input_pixel[2] = int(brightness * input_pixel[2])
    output_pixel[0] = gamma[input_pixel[0]]
    output_pixel[1] = gamma[input_pixel[1]]
    output_pixel[2] = gamma[input_pixel[2]]
    return output_pixel

def write_stream(pixels):
    spidev.write(pixels)
    return

# MAIN
spidev = file(spi_dev_name, "wb")
for i in range(256):
    gamma[i] = int(pow(float(i) / 255.0, 2.5) * 255.0)
Blinker = 0
pixel_output = bytearray(16 * PIXEL_SIZE + 3)
method = 'GET'
body = ''
h = http.Http()

while True:
   responseELW, contentELW = h.request(targetELW.geturl(),method,body,headers)
   ELW = json.loads(contentELW)
   ELWled = int(float(ELW["data"]["tuples"][0][1])) / SCALE
   responseHeizung, contentHeizung = h.request(targetHeizung.geturl(),method,body,headers)
   Heizung = json.loads(contentHeizung)
   Heizungled = int(float(Heizung["data"]["tuples"][0][1])) / SCALE
   responseHaus, contentHaus = h.request(targetHaus.geturl(),method,body,headers)
   Haus = json.loads(contentHaus)
   Haus["data"]["tuples"][0][1] = Haus["data"]["tuples"][0][1] - ELW["data"]["tuples"][0][1]
   Hausled = int(float(Haus["data"]["tuples"][0][1])) / SCALE
   responsePV, contentPV = h.request(targetPV.geturl(),method,body,headers)
   PV = json.loads(contentPV)
   PVled = int(float(PV["data"]["tuples"][0][1])) / SCALE

   led = 0
   print "Haus: ", int(float(Haus["data"]["tuples"][0][1])), "  Hausled: ",Hausled, "PV: ", int(float(PV["data"]["tuples"][0][1])) , "  PVled ",PVled
   for led in range(19):
        pixel_output[led * PIXEL_SIZE:] = filter_pixel(BLACK, 1)
        if Hausled > led:
                pixel_output[(led * PIXEL_SIZE)+0] = '\xff'
        elif (Hausled == led) and (int(float(Haus["data"]["tuples"][0][1])) > 440):
                pixel_output[(led * PIXEL_SIZE)+0] = int(( float(Haus["data"]["tuples"][0][1]) % SCALE) / SCALE * 255)
        if -Hausled > led:
                pixel_output[(led * PIXEL_SIZE)+1] = '\xff'
        elif (-Hausled == led) and ( int(float(Haus["data"]["tuples"][0][1])) < -440):
                pixel_output[(led * PIXEL_SIZE)+1] = int(( float(Haus["data"]["tuples"][0][1]) % SCALE) / SCALE * 255)

        if (PVled > led) and (PVled > -Hausled) and (PVled > Hausled):
                pixel_output[(led * PIXEL_SIZE)+2] = '\xff'
        elif PVled == led:
                pixel_output[(led * PIXEL_SIZE)+2] = int(( float(PV["data"]["tuples"][0][1]) % SCALE) / SCALE * 255)

        if (led == 18):
                if (Blinker == 0):
                        Blinker = 1
                        pixel_output[led * PIXEL_SIZE:] = filter_pixel( bytearray(b'\x00\x1C\x00'), 1)
                else:
                        Blinker = 0
                        pixel_output[led * PIXEL_SIZE:] = filter_pixel(BLACK, 1)

   for c in pixel_output: print(c),
   print('\n')

   write_stream(pixel_output)
   spidev.flush()
   time.sleep(2)