ritika krishna

Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

10 years ago.

confused about xbee mbed rx code

hey ppl.. i need to write a code where one xbee+mbed is trasmitting a particular character (say "A") and the other mbed+xbee is receiver and if it receives "A" then any one of the Led shld glow

i tried writing the code of tx.. but confused abt the RX code

TX code

#include "mbed.h"

Serial xbee1(p9, p10); 
DigitalOut rst1(p11); 

DigitalOut myled(LED3);
DigitalOut myled2(LED4);

Serial pc(USBTX, USBRX);

int main() {
    rst1 = 0; //Set reset pin to 0
    myled = 0;//Set LED3 to 0
    myled2= 0;//Set LED4 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
        if (pc.readable()) {//Checking for serial comminication
            myled = 0; //Turn Led 3 Off
            xbee1.printf("A"); //XBee writes "A"
            myled = 1; //Turn Led 3 on for succcessfull communication
        }
    }
}

RX code 

#include "mbed.h"
 Serial xbee1(p9, p10);
 DigitalOut rst1(p8);
 
 DigitalOut myled(LED1);
 DigitalOut myled2(LED2);
 //TextLCD lcd(p15, p16, p17, p18, p19, p20);
 int main() {

     rst1 = 0;   //Set reset pin to 0
     myled = 0;
     myled2=0;
     wait_ms(1);
     rst1 = 1;   //Set reset pin to 1
     wait_ms(1);
     char X; 

     while (1) {
        if(xbee1.readable()){
             wait(1);
              myled = 1;
             
            xbee1.scanf("%c", &X);
           // X = xbee1.getc();
             wait(1);
             myled = 0;    
             if(X=='A')    
             myled2=1;        
             
             
           }
         }
     }

is the code correct for RX??

3 Answers

Paul Staron
10 years ago.

You could try this; The RTC time is sent from one Mbed to another every 5 seconds.

You can remove oled code and use the TextLCD code instead, I have tried on both.

My Xbee's are on p13 and p14

Xbee RTC TX code

#include "mbed.h"
#include "TextLCD.h"
#include "OLED32028P1T.h"

OLED32028P1T oled(p28, p27, p29);   // Oled Display tx, rx, rs
//TextLCD lcd(p12, p21, p11, p8, p7, p6, p5); // rs, rw, e, d4, d5, d6, d7

DigitalOut myled(LED1);
Serial xbee(p13,p14);  // tx, rx

Ticker t;

 void send(){
        myled=1;           
        time_t seconds = time(NULL);       
        xbee.printf("%d",seconds);       
        myled=0;        
     }

int main() {
    
    oled.init();oled.clear();oled.setTextBackgroundType(TEXT_OPAQUE);
    oled.setFontColor(oled.toRGB(255,255,255));oled.setFontSize(FONT8X12); 
    
    //lcd.cls()
    oled.printf("Send Time every\n");
    //lcd.printf("Send Time every\n");
    
    oled.printf("5 Seconds ");
    //lcd.printf("5 Seconds ");
    
    wait(2);
    
        t.attach(&send, 5);
        
        while (1) {
        
        time_t seconds = time(NULL);
        char buffer[40];
        oled.locate(0,0);
        //lcd.locate(0,0);
        strftime(buffer, 40, "%I:%M:%S %p\n", localtime(&seconds));
        oled.printf("Time %s",buffer);
        //lcd.printf("Time %s\n",buffer);
            
        strftime(buffer, 40, "%a %d %b %Y", localtime(&seconds));
        oled.printf("Date %s",buffer);
        //lcd.printf("Date %s",buffer);  
            
        }
}

Xbee RTC RX code

#include "mbed.h"
#include "TextLCD.h"
#include "OLED32028P1T.h"

//TextLCD lcd(p12, p24, p24, p30, p22, p23, p11); // rs, rw, e, d4, d5, d6, d7
OLED32028P1T oled(p28, p27, p29);   // Oled Display tx, rx, rs

Serial xbee1(p13, p14);
DigitalOut led1(LED1);
DigitalOut led4(LED4);

struct tm t;
int x; 
int count;
char data_buf[10];

int main() {
    
    oled.init();oled.clear();oled.setTextBackgroundType(TEXT_OPAQUE);
    oled.setFontColor(oled.toRGB(255,255,255));oled.setFontSize(FONT8X12);
        
    //lcd.cls();
    wait_ms(10);          

while(1){        
        
        oled.locate(0,0);
        //lcd.locate(0,0);
        
        time_t seconds = time(NULL);
        char buffer[40];
        
        strftime(buffer, 40, "%I:%M:%S %p", localtime(&seconds));
        oled.printf("Time %s\n",buffer);
        //lcd.printf("Time %s\n",buffer); 
           
        strftime(buffer, 40, "%a %d %b %Y", localtime(&seconds));
        oled.printf("Date %s",buffer);
        //lcd.printf("Date %s",buffer); 
       
        if(xbee1.readable())  {
        led1 = 1;count=0;        
        while (count < 10 ) {            
            data_buf[count] = xbee1.getc();
            count++;
            }         
            x = atol(data_buf);   
            set_time(x+1); led4 = 1; // add 1 second for tx/rx delay          
            led1 = 0;     
      } 
     }
   }

i dont have lcd .. i just have two mbed and 2 xbee S2.. so tell me how can i code the program now?

posted by ritika krishna 28 Mar 2014

How do you want to display your output results?

posted by Paul Staron 28 Mar 2014
ritika krishna
10 years ago.

The mbed board has led so i wish that one of the led shuld glow...and hence i wrote the program (led 3) isit not possible??

Aaron Minner
10 years ago.

Are your Xbees configured properly? Are they using the same PAN ID? Is the Node Identifier correct? Can you check these values with the X-CTU tool?