several unit communication problem

Hi i am working on a project and i have a really big problem in coding
I am working with 10 arduinos using 8 channels on each working
i need a way to send different codes to them all at once
For example send "mp" to board1 and "mn" to board 2 at the same second without any delay between them
am using xbee s1 as a radio module

Connect the Master's Tx to the Rx on the slaves. All can 'listen' while 1 talks.

If you need the slaves to be able to talk back, then a different hardware solution is needed.

this is a piece of the code present on the master board
void setup() {
Serial.begin(9600);
}

void loop() {

Serial.print('w1'); Serial.print('w2');
delay(1000);
Serial.print('off1');
delay(100);
Serial.print('w1');
delay(1000);
Serial.print('off1');
delay(100);
Serial.print('w1');
delay(1000);
Serial.print('off1');
delay(100);
}

and this is a piece of the code present on one of the slave boards

if(val=="w1"){
digitalWrite(mk,HIGH);
}

But what happens is that the action doesn't happen on the two boards at once

this is a piece of the code present on the master board
void setup() {
Serial.begin(9600);
}

void loop() {

Serial.print('w1'); Serial.print('w2');
delay(1000);
Serial.print('off1');
delay(100);
Serial.print('w1');
delay(1000);
Serial.print('off1');
delay(100);
Serial.print('w1');
delay(1000);
Serial.print('off1');
delay(100);
}

and this is a piece of the code present on one of the slave boards

if(val=="w1"){
digitalWrite(mk,HIGH);
}

and this one is found on the second board

if(val=="w2"){
digitalWrite(mk,HIGH);
}

But what happens is that the action doesn't happen on the two boards at once there is a slight delay

any help would be appreciated
am using xbee s1 for communication
If someone would be able to help me through a skype conference it would be great

This is the same question as in your other Thread.

Don't Double Post.

I am asking the Moderator to merge them.

...R

I am not familiar with the XBee but I have done this sort of thing with another 2.4GHz transceiver.

In my system the slaves are always listening. The master sends a message with an ID number for a particular slave. When the slave detects its own ID number it replies before it does anything else and the master will listen for a very short period for that reply. It would be easy to have a special ID number that all the slaves would treat as a message for themselves that should be acted on but not replied to.

In my system each slave expects to get a message within X seconds and if i doesn't it will stop working, but will keep listening.

...R

  Serial.print('w1'); Serial.print('w2');

Single quotes are for single characters!

Robin2:
This is the same question as in your other Thread.

Don't Double Post.

I am asking the Moderator to merge them.

...R

Merged