#Script collection demonstrating UDP socket communication in Scorpion.

Central Start:
  import socket
  receivedFromAddress = None # will be set when receiving data
  receivePort = 1501 # listen on this port
  sendToAddress = (sendToIPAddress, sendToPort) # target for sending data
  udp = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
  udp.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
  udp.bind(('', receivePort))
  udp.settimeout(0.01)

Central Stop:
  udp = None

# to be called at short intervals from a timer
# ensure no time-consuming tasks are done inside this function.
def Receive():
  global udp
  global receivedFromAddress
  if udp == None:
    print 'no udp object'
    return
  bufsize = 16384
  try:
    data, receivedFromAddress = udp.recvfrom(bufsize)
  except socket.timeout:
    return # no data waiting in buffer
  except Exception, err:
    print 'recv exception:', err
    return
  print 'Received %d bytes from' % len(data), receivedFromAddress
  #use the data string

def Send(data):
  global udp
  sendToIPAddress = '127.0.0.1'
  sendToPort = 1500
  sendToAddress = (sendToIPAddress, sendToPort)
  if udp <> None:
    try:
      udp.sendto(data, sendToAddress)
    except Exception, err:
      print 'Send exception: ', err
      return
  else:
    print 'Send: No socket object'