connection between two ARDUINO with xbee I have a setup where two XBEES modules are talking to each other, both using XBEE shields, one attached to an UNO ARDUINO and the other a MEGA ARDUINO. One XBEE sends the data and the other receives it and switch on or off a LED. 
The problem is the receiver one don't work. 
This is the sender code 

int led = 13;
const int bouton = 2; String inputString;
void setup() {
pinMode(led, OUTPUT);
Serial1.begin(9600);
Serial.begin(9600);
digitalWrite(led, LOW);
}
void loop() {
while (Serial.available() ) {
// get the new byte:
delay(3);  
char inChar = Serial.read();
// add it to the inputString:
inputString += inChar;
}
if (inputString.length() &gt;0) {
Serial.println(inputString);
Serial1.println(inputString);
inputString=""; 
}
} 


This the receiver one 

int led = 13;
String inputString;
void setup() {
// put your setup code here, to run once:
pinMode(led, OUTPUT);
Serial.begin(9600);
}
void loop() {
while (Serial.available() ) {
// get the new byte:
delay(3);  
char inChar = Serial.read();
// add it to the inputString:
inputString += inChar;   
}

if (inputString.length() &gt;0) {
Serial.println(inputString);
if (inputString == "on"){
digitalWrite(led,HIGH);
Serial.println("LED ON");
}

if (inputString == "off"){
digitalWrite(led,LOW);
   Serial.println("LED OFF");
}
inputString=""; 
}
}


I get on the serial monitor of ARDUINO UNO what i wrote in the serial monitor of ARDUINO MEGA but the LED don't switch on or off :/
Probably you are getting a new character/carrier return (\n or \n\r) in your receivers' string, that is why it won't match exactly "on" or "off", it will be "on\n", "on\r\n" or similar.