OlaLED

Introduction

In this topic, you will learn how to install a python script to permit to control a LED / RGB system via webcontrol (or other python script)

prerequisites

You need to have a fully functional ola system

Install script

create a directory to store all these new functionnality

 mkdir -p /srv/dmx/

write a this new python script in this folder :

 nano /srv/dmx/server.py

 #!/usr/bin/python
 
 import SocketServer
 import threading
 import time
 from ola_send_dmx import *
 
 my_thread = 0
 my_command = 'start'
 
 actual_program = 'color'  ## program wanted
 param1 = 'red'  ## first param
 intensity = 100 ## current intensity
 actual_fixed_color = 0 ## if fixed color choice, put args here to remember (if having to change intensity)
 R_before = 0  # current color state
 G_before = 0  
 B_before = 0

 pitch = 1

 class MyTCPHandler(SocketServer.BaseRequestHandler):
   """
   The RequestHandler class for our server.

   It is instantiated once per connection to the server, and must
   override the handle() method to implement communication to the
   client.
   """
 
   def handle(self):
       # self.request is the TCP socket connected to the client

global my_thread

       self.data = self.request.recv(1024).strip()

# was a test #if self.data == 'reset' : # global my_command # my_command = 'reset' #else :

command = self.data.split() command = command[0]

if command == 'intensity': # We separe intensity because should lauch in parallel another_thread = Thread_dmx(self.data) # thread named different for able controlling mythread another_thread.start() print "thread intensite lance" # just send back the same data, but upper-cased self.request.send(self.data.upper()) else: if my_thread != 0 : #if thread is already launched and is not about intensity try: my_thread.stop() #stop thread my_thread.join() #stop program to be sure thread is stopped except NameError: print "An error occured when trying to stop previous thread." print "launching thread " + self.data my_thread = Thread_dmx(self.data) my_thread.start() # just send back the same data to the client, but upper-cased self.request.send(self.data.upper())

 class Thread_dmx(threading.Thread):
 

def __init__(self, nom = ): threading.Thread.__init__(self) self.nom = nom self.Terminated = False def run(self): global actual_program global intensity global fixed_color ## separate command and arguments ## words = self.nom.split() if len(words) == 0: print('Error: empty request\n') return

command = words[0] args = words[1:]

methodname = 'do_' + command

## relauch sending DMX for fixed color, if intensity changed if command=='intensity':

intensity = abs(int(args[0])) if intensity > 100: return if actual_program == 'fade': method = getattr(self, 'do_fade') method(*fixed_color)

else:

actual_program = command

## take care of inexistent function if not hasattr(self, methodname): print('Error: ',command,' is not a valid command') return

## save color if fixed color if command=='fade': fixed_color = args

## launch corresponding function method = getattr(self, methodname) method(*args)

## Stop the thread if called def stop(self): self.Terminated = True

## Go to specified DMX adresses from previous adresses in fade def do_fade(self,R_after,G_after,B_after,speed):

global R_before global G_before global B_before global intensity

R_after=int(round((int(R_after)*intensity)/100)) G_after=int(round((int(G_after)*intensity)/100)) B_after=int(round((int(B_after)*intensity)/100))

if(R_after==R_before and G_after==G_before and B_after==B_before): print('Etat deja atteint') return

speed=float(speed)

actual_intensity = intensity time_to_sleep=(speed/max(abs(R_before-R_after),abs(G_before-G_after),abs(B_before-B_after)))

               # count to know wich pitch to apply (processor free)
 
               speed_reference=float(0.01)
               print(time_to_sleep)
               pitch=int(speed_reference/time_to_sleep)
               print(pitch)
               if pitch == 0:
                       pitch = int(1)
               print(pitch)
 
 

## while ending color are not reached or no order for stopping, increment data while (R_before-R_after!=0 or G_before-G_after!=0 or B_before-B_after!=0) and (not self.Terminated) : ## If intensity was changed, take care of this if actual_intensity != intensity: R_after=int(round((int(R_after)*intensity)/100)) G_after=int(round((int(G_after)*intensity)/100)) B_after=int(round((int(B_after)*intensity)/100)) actual_intensity = intensity

R_diff=R_before-R_after G_diff=G_before-G_after B_diff=B_before-B_after

if R_diff <= -pitch : R_before += pitch elif R_diff >= pitch : R_before-= pitch else : R_before = R_after if G_diff <= -pitch : G_before += pitch elif G_diff >= pitch : G_before -= pitch else : G_before=G_after if B_diff <= -pitch : B_before += pitch elif B_diff >=pitch : B_before -= pitch else : B_before=B_after

#print('AFTER : ',R_after,G_after,B_after) print('values =',R_before,G_before,B_before) print('sleep =',time_to_sleep*pitch) print('pitch =',pitch) dmx_send(R_before,G_before,B_before) time.sleep(time_to_sleep*pitch)

## make a chase from red to blue, indefinitely def do_chase(self,speed): intensity = 255 speed = float(speed) while not self.Terminated :

                       self.do_fade(intensity,0,intensity,speed)
                       print("7")

print("1") self.do_fade(intensity,0,0,speed) print("2") self.do_fade(intensity,intensity,0,speed) print("3") self.do_fade(0,intensity,0,speed) print("4") self.do_fade(0,intensity,intensity,speed) print("5") self.do_fade(0,0,intensity,speed) print("6") #self.do_fade(intensity,0,intensity,speed) #print("7")

 if __name__ == "__main__":
   HOST, PORT = "localhost", 9999
 
   # Create the server, binding to localhost on port 9999
   server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)
 
   # Activate the server; this will keep running until you
   # interrupt the program with Ctrl-C
   server.serve_forever()

copy client_wrapper.py in this folder :

 cp /usr/src/ola-0.7.4/python/examples/client_wrapper.py /srv/dmx/

create a new python file function : ola_send_dmx.py

 nano /srv/dmx/ola_send_dmx.py