A simple TCP server written in Python to control the Arduino board, it receives the signals over TCP connection, and sends them to the Arduino board using serial.

Arduino TCP Server

#!/usr/bin/env python
#
# Copyright 2011 Abdulrahman Alotaiba
# http://www.mawqey.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 3 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.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import SocketServer
import serial
import time

HOST = ''
PORT = 50000
BAUD_RATE = 9600
SERIAL_PORT = '/dev/tty.usbmodem411'

class ArduinoTCPHandler(SocketServer.BaseRequestHandler):
	def handle(self):
		try:
			arduino = serial.Serial(SERIAL_PORT, BAUD_RATE)
			print "Connected to Arduino successfully.\n"
			print "%s" % (arduino.readline())
		except:
			print "Failed to connect Arduino on %s" % (SERIAL_PORT)
		
		self.request.send("\r\nType a number between 0 and 9 - 'Q' to quit!\n\r")
		
		print "%s is connected" % self.client_address[0]
		try:
			while True:
				self.data = self.request.recv(1024).strip()
				print self.data
				try:
					char = int(self.data)
					if (0 <= char < 10):
						arduino.write(str(char))
					else:
						continue
				except ValueError:
					if self.data.upper() == 'Q':
						break
					else:
						pass
		except IOError:
			print "Connection to peer has been lost.\r\n"

try:
	print 'Waiting for a connection...'
	server = SocketServer.TCPServer((HOST, PORT), ArduinoTCPHandler, False)
	server.allow_reuse_address = True
	server.server_bind()
	server.server_activate()
	server.serve_forever()
except KeyboardInterrupt:
	print 'Terminating Server...'
	server.socket.close()