void setup() 
{ 
  long i;
  Serial.begin(9600);  
  i=analogRead(0); // any analog channel will do 
  randomSeed(i); 
  Serial.print("Noise voltage: "); 
  Serial.println(i); 
} 
void loop() 
{
  long a; 
  a = random(50,1000); 
  Serial.println(a); 
  delay(2000); 
}