[PIC] REceive uart data as hex value

[ajit_nayak87]

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.

my questions:

1) how to receive data from uart as string
2) how to receive hex value.

 

[KlausST]

Hi,

When i try to send data 0103000000Ac5CD In ASCii

What is "0103000000Ac5CD"?
I assume it is a string...and a string already is a array of ASCII characters.

I don't kniw if this is your problem..
But there are (at least) two types of how a string is stored:
* one type has only one byte per character
* and the other has two bytes per character.

You need to read compiler documentation. Maye you can adjust it.

Klaus

 

[paulfjujo]

hello,



Where is defined Lt ?

i don't undestand this

if(sizeof(eusartRxBuffer) <= eusartRxTail)

maybe this could be more correct ?

if((sizeof(eusartRxBuffer) & lt )== eusartRxTail)

 

[rajat2905]

use sprintf of c stdio library