sending and receiving bytes

[butters]

#include <p18f452.h>
#include <usart.h>
#include <delays.h>

void rx_handler (void);//declare the ISR function.HIGH
void pull_chord (void);//declare the ISR function.LOW


#define BUF_SIZE 25

/*
 * Step #1  The data is allocated into its own section.
 */

#pragma idata bigdata
char data[11][BUF_SIZE+1] = {
  { "String #0\n\r" },
  { "String #1\n\r" },
  { "String #2\n\r" },
  { "String #3\n\r" },
  { "String #4\n\r" },
  { "String #5\n\r" },
  { "String #6\n\r" },
  { "String #7\n\r" },
  { "String #8\n\r" },
  { "String #9\n\r" },
  { "Invalid key (0-9 only)\n\r" }
};
#pragma idata


//location of the ISR.(HIGH)
#pragma code rx_interrupt = 0x8
void rx_int (void)
{
  _asm goto rx_handler _endasm
}
#pragma code  //return to default code section


//location of the ISR.(LOW)
#pragma code low_pull = 0x18
void low_pull (void)
{
  _asm goto pull_chord _endasm
}
#pragma code  //return to default code section





#pragma interruptlow pull_chord
void pull_chord (void)
{

/*  OMG WHAT TO PUT?     */

}



#pragma interrupt rx_handler
void rx_handler (void)
{
  unsigned char c;

  /* Get the character received from the USART */
 c = ReadUSART() ;
  if (c >= '0' && c <= '9')
    {
      c -= '0';
      /* Display value received on LEDs */
      PORTB = c;


	  //enables driver so it can transmit value to hyperterm
      PORTCbits.RC5 = 1;
      putsUSART (data[c]);// writes string of character from data[c]
         
      //disables
      PORTCbits.RC5 = 0;

}
  else
    {
	  //enable driver
      PORTCbits.RC5 = 1;

      putsUSART (data[11]);

      /* Display value received on LEDs */
      PORTB = c;

	  //disable driver
	  PORTCbits.RC5 = 0;
    }


    /* Clear the interrupt flag */
    PIR1bits.RCIF = 0;
}



void main (void)
{
ADCON1 = 0x0F;
TRISCbits.TRISC5 = 0;

//LED
TRISB = 0;


  OpenUSART (USART_TX_INT_OFF &
             USART_RX_INT_ON &
             USART_ASYNCH_MODE &
             USART_EIGHT_BIT &
             USART_CONT_RX &
             USART_BRGH_HIGH, 25);


//lighting up LED at RB0
PORTCbits.RC5 = 1;

	//value sent
	putcUSART(0x31);//1st byte
Delay10KTCYx(50);

PORTCbits.RC5 = 0;


PORTCbits.RC5 = 1;

	//value sent
	putcUSART(0x41);//2nd byte
Delay10KTCYx(50);

PORTCbits.RC5 = 0;


PORTCbits.RC5 = 1;

	//value sent
	putcUSART(0x4f);//3rd byte
Delay10KTCYx(50);

PORTCbits.RC5 = 0;


PORTCbits.RC5 = 1;

	//value sent
	putcUSART(0x65);//4th byte
Delay10KTCYx(50);

PORTCbits.RC5 = 0;




/* Enable interrupt priority */
 RCONbits.IPEN = 1;

  /* Make receive interrupt high priority */
  IPR1bits.RCIP = 1;

  /* Enable all high priority interrupts */
  INTCONbits.GIEH = 1;

/* Enable all low priority interrupts */
  INTCONbits.GIEL = 1;

  /* Loop forever */
  while (1)
    ;
}

i am currently able to send 4 static bytes to hyperterminal via rs-485.. whereby if PORTCbits.RC5 = 1 is present, the rs-485 sending part would be activated and send the respective static hex values... and when PORTCbits.RC5 = 0, it would enable the rs-485 receiving part and would interrupt the main programme... and hence serve the interrupt...

my problem is that how do i send dynamic hex values...? do i need arrays?

 

[Pommie]

What do you mean by "dynamic hex values"? What do you want to send and how should it appear at the PC end.

Mike.

 

[butters]

its suppose to display "fame"

 

[Pommie]

There are two ways to do that depending on whether the message is in Ram or Rom.

void PutMessage(rom char *Message){		//send a ROM message
    while(*Message!=0)
        putcUSART(*Message++);
} 

void main(){
char RamBuffer[]="Hello World\0x0d\0x0a";	//Message in RAM
char i;
    PutMessage((rom char*)"fame\0x0d\0x0a");	//Message in ROM
    i=0;
    while(RamBuffer[i]!=0){
        putcUSART(RamBuffer[i++]);
    }
}

I added the new line characters.

Mike.