int outPin = 11;
int val;
int arpPoison = 0;
int red;

void setup()
{
  pinMode(outPin, OUTPUT); // sets the digital pin as output
  Serial.begin(9600);
  Serial.flush();
}

void loop()
{
  // Read from serial port
  if (Serial.available())
  {
    val = Serial.read();
    Serial.print(val);
    if (val == 'A')
    {
       arpPoison = 1;
       for(red = 0; red <= 255; red+=5)
       {
         analogWrite(outPin, red);
         delay(30);
       }
       while (arpPoison == 1)
       {
         for(red = 255; red >= 25; red-=5)
         {
           analogWrite(outPin, red);
           delay(30);
         }
         for(red = 25; red <= 255; red+=5)
         {
           analogWrite(outPin, red);
           delay(30);
         }
         val = Serial.read();
         Serial.print(val);
         if (val == 'R')
         {
           arpPoison = 0;
           for(red = 255; red >= 0; red-=5)
           {
             analogWrite(outPin, red);
             delay(30);
           }
         }
       }
    }
  }
}

import sys, subprocess, serial
if len(sys.argv) != 3:
   print "syntax: " + sys.argv[0] + " <Network Interface> <Serial Interface>\n"
   exit()
try:
   ser = serial.Serial(sys.argv[2], 9600)
except serial.SerialException:
   print "Error: Could not setup Serial Port!"
   sys.exit()
ettercap = subprocess.Popen("ettercap -i " + sys.argv[1] + " -TQP arp_cop //", shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
try:
   while 1:
      inPut = ettercap.stdout.readline()
      inPut = inPut.split(' ')
      for msg in inPut:
         if msg == "(WARNING)":
            print "Arp Poisoning Detected!"
            ser.write('A')
except:
   ser.write('R')
   print "Terminated!"
#out = ettercap.communicate('q')[0]
#print "Done!"