// Master code 

int PO = A0;        

int A = 0;          

void setup() {
  // put your setup code here, to run once:
Serial.begin(38400);
}

void loop() {
  // put your main code here, to run repeatedly:
//communication
int x=analogRead(PO);     
if (x==0){
 A = 1 ;                     
}

if (x>400){
  A = 2 ;
}
  Serial.write (A);       //send the value of A to the other chip
  Serial.print (A);
  Serial.print ("    ");
Serial.println(x);
}