user2824: I am following this tutorial to learn about Arduino wireless communication. I have 2 Arduino unos with Xbee S1s sitting on Xbee Pro shields. 
I've programmed the Xbee S1s by screening into the /dev/tty/* and configuring them with: +++, ATID1234, ATMY1000 (ATMY1001), ATDL1001 (ATDL1000) and ATWR. I've double checked the values to ensure they are correct. 
So i've created a super simple Sender and Receiver package:
Sender.ino
int counter = 0;

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println(counter++);
  delay(1000);
}

Receiver.ino:
void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println("Looping");
  while (Serial.available() == 0);    // wait
  int counter = Serial.parseInt();
  Serial.println(counter);
  Serial.flush();
  delay(500);
}

So first of all, when I upload my program to my arduino, I make sure that the S1s are not attached to the Pro shields which is attached to the unos. 
When both of my unos are powered, I see a red light blinking but no indication of "busy blinking" which is supposed to happen when two XBee S1s are connected to the same channel. I am currently seeing a consistent blinking at about 1 second frequency.
Can someone tell me why I am only able to see "Looping" in my Serial monitor on my receiver? 

user10794: blah reported:

So I was just hacking around and I finally figured out what went wrong! Apparently, there's a switch "XBEE/USB" that needs to be switched to XBEE for BOTH shields. After that, everything works as planned.

Can someone vote this up please to remove it from the unanswered queue?

2824: <p>I am following this <a href="https://www.youtube.com/watch?v=vKVNmA8C6m8" rel="nofollow">tutorial</a> to learn about Arduino wireless communication. I have 2 Arduino unos with Xbee S1s sitting on Xbee Pro shields. </p>

<p>I've programmed the Xbee S1s by screening into the /dev/tty/* and configuring them with: <code>+++, ATID1234, ATMY1000 (ATMY1001), ATDL1001 (ATDL1000)</code> and <code>ATWR</code>. I've double checked the values to ensure they are correct. </p>

<p>So i've created a super simple Sender and Receiver package:</p>

<p>Sender.ino</p>

<pre><code>int counter = 0;

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println(counter++);
  delay(1000);
}
</code></pre>

<p>Receiver.ino:</p>

<pre><code>void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println("Looping");
  while (Serial.available() == 0);    // wait
  int counter = Serial.parseInt();
  Serial.println(counter);
  Serial.flush();
  delay(500);
}
</code></pre>

<p>So first of all, when I upload my program to my arduino, I make sure that the S1s are not attached to the Pro shields which is attached to the unos. </p>

<p>When both of my unos are powered, I see a red light blinking but no indication of "busy blinking" which is supposed to happen when two XBee S1s are connected to the same channel. I am currently seeing a consistent blinking at about 1 second frequency.</p>

<p>Can someone tell me why I am only able to see "Looping" in my Serial monitor on my receiver? </p>
 10794: <p><strong>blah</strong> reported:</p>

<blockquote>
  <p>So I was just hacking around and I finally figured out what went wrong! Apparently, there's a switch "XBEE/USB" that needs to be switched to XBEE for BOTH shields. After that, everything works as planned.</p>
</blockquote>

<p>Can someone vote this up please to remove it from the unanswered queue?</p>
