cheertree.py

import urllib2
import json
import time
import unicornhat as UH

lastID = 0      #most recent entry_id
refresh = 15    #refresh time in secs
urlRoot = "http://api.thingspeak.com/channels/1417/"
pixels = []    #list of pixels and their colours
pattern =        [[3,0],
  	    [2,1],[3,1],[4,1],
      [1,2],[2,2],[3,2],[4,2],[5,2],
            [2,3],[3,3],[4,3],
      [1,4],[2,4],[3,4],[4,4],[5,4],
[0,5],[1,5],[2,5],[3,5],[4,5],[5,5],[6,5],
		  [3,6],
		  [3,7]]

lights = [[3,0],[2,2],[4,2],[3,4],[1,5],[5,5]]
mode = 1	#0=all pixels, 1=lights list only, 2=star only

if mode == 0:
    maxPixels = len(pattern)
elif mode == 1:
    maxPixels = len(lights)
elif mode == 2:
    maxPixels = 1

namesToRGB = {'red': [0xFF, 0, 0],
                'green': [0, 0x80, 0],
                'blue': [0, 0, 0xFF],
                'cyan': [0, 0xFF, 0xFF],
                'white': [0xFF, 0xFF, 0xFF],
                'warmwhite': [0xFD, 0xF5, 0xE6],
                'purple': [0x80, 0, 0x80],
                'magenta': [0xFF, 0, 0xFF],
                'yellow': [0xFF, 0xFF, 0],
                'orange': [0xFF, 0xA5, 0],
                'pink': [0xFF, 0xC0, 0xCB],
                'oldlace': [0xFD, 0xF5, 0xE6]}


#retrieve and load the JSON data into a JSON object
def getJSON(url):
	try:
		jsonFeed = urllib2.urlopen(urlRoot + url)
		feedData = jsonFeed.read()
		#print feedData
		jsonFeed.close()
		data = json.loads(feedData)
		return data
	except urllib2.HTTPError, e:
		print 'HTTPError = ' + str(e.code)
	except urllib2.URLError, e:
		print 'URLError = ' + str(e.reason)
	except httplib.HTTPException, e:
		print 'HTTPException'
	except Exception:
		import traceback
		print 'generic exception: ' + traceback.format_exc()

	return []		

#use the JSON object to identify the colour in use,
#update the last entry_id processed
def parseColour(feedItem):
    global lastID
    global pixels

    for name in namesToRGB.keys():
        if feedItem["field1"] == name:
            if mode != 0 and name == 'green':	#ignore green when in lights or star mode
                name = "yellow" 
            pixels.insert(0, namesToRGB[name])    #add the colour to the head
            break

    lastID = getEntryID(feedItem)

#read the last entry_id
def getEntryID(feedItem):
    if len(feedItem) == 0:
        return -1
    return int(feedItem["entry_id"])

#refresh the displayed pixels
def showPixels():
    global pixels
    index = 0

    if mode != 0:		#green tree
        for coords in pattern:
            UH.set_pixel(coords[0],coords[1], 0, 0xFF, 0)
	
    for pixel in pixels:
        if mode == 0:
            coords = pattern[index]
        else:
            coords = lights[index]
        UH.set_pixel(coords[0],coords[1], pixel[0], pixel[1], pixel[2])
        index += 1
        if index >= maxPixels:
            #print index, maxPixels
            pixels = pixels[:maxPixels-1]    #trim the list as we've maxed out
            break
    UH.show()

#show all pixels one colour
def showColour(c):
    for coords in pattern:
        UH.set_pixel(coords[0], coords[1], c[0], c[1], c[2])
    UH.show()
                  
#main program

UH.rotation(180)
UH.brightness(0.4)

#process the currently available list of colours
data = getJSON("feed.json")
if mode != 2 and len(data) > 0:
    for feedItem in data["feeds"]:
        parseColour(feedItem)
    showPixels()

#check for new colour requests
while True:
    data = getJSON("field/1/last.json")
    
    if getEntryID(data) > lastID:   #Has this entry_id been processed before?
        parseColour(data)
        showColour(pixels[0])
        #if mode != 2:
        time.sleep(5)
        showPixels()
    else:
        time.sleep(refresh)