xbee transmitter and receiver

Questions » xbee transmitter and receiver

9 years, 10 months ago.

i'm testing a simple Xbee wireless communication, while the receiver can only receive the data in the first second, and it will not receive any data any more after that, can anybody check my code.

transmitter

#include "mbed.h"
#include "C12832.h"

C12832 lcd(p5, p7, p6, p8, p11);
Serial pc(USBTX, USBRX);
Serial xbee1(p9,p10);
 DigitalOut rst1(p30); //Digital reset for the XBee, 200ns for reset
 DigitalOut myled(LED3);//Create variable for Led 3 on the mbed
 
int main() { 
 
    rst1 = 0; //Set reset pin to 0
    myled = 0;//Set LED3 to 0
    wait_ms(1);//Wait at least one millisecond
    rst1 = 1;//Set reset pin to 1
    wait_ms(1);//Wait another millisecond

     
    while (1) {//Neverending Loop
        
        myled = 1; //Turn Led 3 Off
        float a;
      
        a=10.655;
       
        xbee1.printf("%f",a); //XBee write whatever the PC is sending
       // xbee1.putc(b);
            wait(0.5);
            myled = 0; //Turn Led 3 on for succcessfull communication
            wait(0.5);
            
          
    lcd.cls();
    lcd.locate(0,3);
    lcd.printf("%f",a);
          
        }
    }

receiver

#include "mbed.h"
#include "C12832.h"

C12832 lcd(p5, p7, p6, p8, p11);
 Serial xbee(p9, p10);
 Serial pc(USBTX, USBRX);
 
 DigitalOut rst1(p30);

 DigitalOut myled2(LED2);

 int main() {
 
     rst1 = 0;   //Set reset pin to 0
     myled2=0;
     wait_ms(1);
     rst1 = 1;   //Set reset pin to 1
     wait_ms(1);
     float X; 
  
     while (1) {

        if(xbee.readable()){
             
            xbee.scanf("%f", &X);
        //    X = xbee.getc();
            // wait(1);
             myled2 = 1;   
                
              wait(0.5);
              myled2 = 0;
              wait(0.5);
    lcd.cls();
    lcd.locate(0,3);
    lcd.printf("%f",X);        
           }      
         } 
     }

Could you please wrap your code in << code >><</ code >> (without the spaces between the word and the brackets)? I'm not sure what is a comment and what is code

posted by Brian Daniels 18 Mar 2015

oh sry about that, i will show you the image, thanks for your reply!

posted by qi mao 18 Mar 2015

2 Answers

9 years, 10 months ago.

Still no good, check the 'Editing tips' to add your code to the questions.

However, using Xbee as a receiver, code needs to be implemented on an 'interrupt' serial basis with your program checking the responses otherwise the data will be sent but the receiver may well 'miss' the transmission. Ideally both transmitter and receiver should be using interrupt serial with some form of handshaking.

can u see it now? when i change the printf() to putc(), the receiver could receive the integer number. while when transmit a float number the scanf() only show the number after the decimal point

posted by qi mao 18 Mar 2015

I don't use scanf, but you could try lcd.printf("%2.3f",X);

posted by Paul Staron 18 Mar 2015

-deleted-

9 years, 10 months ago.

The following related question might help: http://developer.mbed.org/questions/6745/How-to-use-an-Interrupt-ISR-for-receivin/

i added \r\n in the printf() function and it works now, but only the third and sixth is not currect.

posted by qi mao 21 Mar 2015

qi mao

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9 years, 10 months ago.