Receive hex data and string using UART communication in Mplab x

[ajit.nayak]

I am using Mplab x Ide with v3.61 on Xc8 compiler, PIC18F24K40. I used MCC generated UART code for send and receive data. For understanding I am clubling my code and posting part of it.

My main code look like this

#include "mcc_generated_files/mcc.h"
#define EUSART_TX_BUFFER_SIZE 8
#define EUSART_RX_BUFFER_SIZE 8

/**
  Section: Global Variables
*/

volatile uint8_t eusartTxHead = 0;
volatile uint8_t eusartTxTail = 0;
volatile uint8_t eusartTxBuffer[EUSART_TX_BUFFER_SIZE];
volatile uint8_t eusartTxBufferRemaining;

volatile uint8_t eusartRxHead = 0;
volatile uint8_t eusartRxTail = 0;
volatile uint8_t eusartRxBuffer[EUSART_RX_BUFFER_SIZE];
volatile uint8_t eusartRxCount;

#define LED_RX RC7 // Pin assigned RX LED
#define LED_TX RC6 // Pin assigned TX LED
#define LED RC2 // Pin assigned for LED 
#define DE RC5

unsigned int count=0;
char data=0;
static int DEVICE_ID=1;
char rxbuf[50]=" ";
unsigned char Function_code=0X03;
static int index=0;
static int rec_flag = 0;
static int check_flag = 1;

unsigned char buff[10];

char data1[10];
unsigned char buf[20]; //array to hold twenty bytes

void EUSART_Initialize(void)
{
    // disable interrupts before changing states
    PIE3bits.RCIE = 0;
    PIE3bits.TXIE = 0;

    // Set the EUSART module to the options selected in the user interface.

    // ABDOVF no_overflow; SCKP Non-Inverted; BRG16 16bit_generator; WUE disabled; ABDEN disabled; 
    BAUD1CON = 0x08;

    // SPEN enabled; RX9 8-bit; CREN enabled; ADDEN disabled; SREN enabled; 
    RC1STA = 0xB0;

    // TX9 8-bit; TX9D 0; SENDB sync_break_complete; TXEN enabled; SYNC asynchronous; BRGH hi_speed; CSRC master; 
    TX1STA = 0xA4;

    TRISCbits.TRISC7 = 1; //As Prescribed in Datasheet
    TRISCbits.TRISC6 = 1; 
    RC1STAbits.CREN=1;
    TX1STAbits.TXEN=1;

    // Baud Rate = 9600; SP1BRGL 207; 
    SP1BRGL = 0xCF;

    // Baud Rate = 9600; SP1BRGH 0; 
    SP1BRGH = 0x00;

    // initializing the driver state
    eusartTxHead = 0;
    eusartTxTail = 0;
    eusartTxBufferRemaining = sizeof(eusartTxBuffer);

    eusartRxHead = 0;
    eusartRxTail = 0;
    eusartRxCount = 0;

    // enable receive interrupt
    PIE3bits.RCIE = 1;
}

uint8_t EUSART_Read(void)
{
    uint8_t readValue = 0;

    while(0 == eusartRxCount)
    {
    }

    readValue = eusartRxBuffer[eusartRxTail++];
    if(sizeof(eusartRxBuffer) <= eusartRxTail)
    {
        eusartRxTail = 0;
    }
    PIE3bits.RCIE = 0;
    eusartRxCount--;
    PIE3bits.RCIE = 1;
    eusartRxBuffer[8];

    return readValue;
}

void EUSART_Write(uint8_t txData)
{
    while(0 == eusartTxBufferRemaining)
    {
    }

    if(0 == PIE3bits.TXIE)
    {
        TX1REG = txData;
    }
    else
    {
        PIE3bits.TXIE = 0;
        eusartTxBuffer[eusartTxHead++] = txData;
        if(sizeof(eusartTxBuffer) <= eusartTxHead)
        {
            eusartTxHead = 0;
        }
        eusartTxBufferRemaining--;
    }
    PIE3bits.TXIE = 1;
}

char getch(void)
{
    return EUSART_Read();
}

void putch(char txData)
{
    EUSART_Write(txData);
}

void EUSART_Transmit_ISR(void)
{

    // add your EUSART interrupt custom code
    if(sizeof(eusartTxBuffer) > eusartTxBufferRemaining)
    {
        TX1REG = eusartTxBuffer[eusartTxTail++];
        if(sizeof(eusartTxBuffer) <= eusartTxTail)
        {
            eusartTxTail = 0;
        }
        eusartTxBufferRemaining++;
    }
    else
    {
        PIE3bits.TXIE = 0;
    }
}

void EUSART_Receive_ISR(void)
{

    if(1 == RC1STAbits.OERR)
    {
        // EUSART error - restart

        RC1STAbits.CREN = 0;
        RC1STAbits.CREN = 1;
    }

    // buffer overruns are ignored
    eusartRxBuffer[eusartRxHead++] = RC1REG;
    if(sizeof(eusartRxBuffer) <= eusartRxHead)
    {
        eusartRxHead = 0;
    }
    eusartRxCount++;
}

/* Send Data Serially */
 void send_string(const char *x)
 {
     while(*x)
     {
        EUSART_Write(*x++); 
     }
 }

/* Timer Interrupt Service Routine Program*/
void Blink_Count()
{
   if(PIR0bits.TMR0IF == 1)
   { 
       PIR0bits.TMR0IF =0;
       count=count+1;
       if(count>=15)
       {
          // LED=!LED;
           count=0;

       }

   }

}

void main(void)
{

    while (1)
    {
   data= EUSART_Read();
     rxbuf[10]=data;
     printf("%s\n",&rxbuf[10]);
     __delay_ms(150);

    }

} 

And tested Serial communication. with this code i could print welcome on Serial Monitor

void main(void)
{
  EUSART_Initialize();
    while (1)
    {
     char array[20] = "Hello World";
     printf("%s\n",array);
      __delay_ms(150);

    }

}

The problem i am facing is. When i try to send data 0103000000Ac5CD In ASCii format i receice as charcter ,but when i try to send in hex format i could not able to receive nothing. If am printing data like i used in working hello print example i got garbage value

[rproffitt]

What I wonder if you are actually clubling the most common reason for serial woes is the setting of the baud rates on the terminal to match your transmit speed. This is the usual the trial by fire for the new embedded programmer.

clubling (plural clublings) (rare) One who frequents or belongs to a club; club attender or member

I usualy see code to set the clock rate but haven't written code on the PIC for about a decade. Be sure to post in their forums:
http://www.microchip.com/forums/f165.aspx

[itnavigate]

The output doesn't look like garbage to me, it looks like the input characters separated by a line feed character. Possible you have a '\n' in a loop.