uart communication on pic16F886A

[ajit]

I am testing UART communication using 20Mhz crystal, 16Bit.Asyn mode.9600 baudarte.

With below setting i am getting garbage value . kindly letme know if any mistake done 

 

 

#include <htc.h>

#include <stdio.h>

#include<pic.h>

#include<stdint.h>

#include "delay.h"

#define _XTAL_FREQ 20000000

unsigned int i=0;   

  unsigned char c=0;

  unsigned char ch;

 

#define SBIT_TXEN     5

#define SBIT_SPEN     7

#define SBIT_CREN     4

 

 

 

 

#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

#define RECEIVE     0

#define TRANSMIT 1

#define READ_REG     3

#define WRITE_REG   6

#define ILLEGAL_DATAVALUE 0x03

#define FALSE   0

#define TRUE 1

#define METER_ID        1

unsigned int j=0;

unsigned char* str;

unsigned int count = 0;

char data = 0;

unsigned char rxbuf[50];

unsigned char ser_data[95];

unsigned char crc_data[95];

unsigned char Max_scroll = 0;

unsigned char buff[10];

volatile uint8_t index = 0, rec_flag = 0, Delay_count = 0, Id[10], Buffer_count = 0, Cal_count = 0, Disp_count = 0, inc = 0, One_sec_update = 0, Auto_scroll_count = 0;

char data1[10];

unsigned char buf[20];

 

 

unsigned short int cnt, num,Dgt=0;

 

unsigned int j;

#define  Notes_Index 25

 

unsigned int Toff_counter=0;

unsigned int POn_Flag=1;

unsigned int Poff_Flag=0;

 

 

 

 

void Serial_1_Send_byte(uint8_t trbuf1) 

{

 TXREG = trbuf1;

  while(TXIF==0);    // Wait till the transmitter register becomes empty

}

 

 

void Send_string_uart1(const unsigned char *string) 

{

    unsigned char i = 0;

 

    do {

        TXREG = string[i++];

        while(!TXIF);    // Wait till the transmitter register becomes empty

    } while (string != '');

}

 

char Serial_Receive_byte()

{

   

   while(!RCIF);

    return RCREG;

    

}

 

char usart_RxString()

{

 

   while(*str !='')

   {            // while not end of string

      while(0==PIR1bits.RCIF);

       RCREG = *str;            // read next character 

       str++;                    // increment pointer to next character

   }

       return RCREG;    // return the contents of uart

}

 

 

void UART_TxChar(char ch)

{

    while(TXIF==0);    // Wait till the transmitter register becomes empty

    TXIF=0;            // Clear transmitter flag

    TXREG=ch;          // load the char to be transmitted into transmit reg

}

 

 

char UART_RxChar()

{

    while(RCIF==0);    // Wait till the data is received 

    RCIF=0;            // Clear receiver flag

    return(RCREG);     // Return the received data to calling function

}

 

 

 

void Timer1_Interrupt()

{

 

INTCON = 0b00000000;

PIE1=0b00000001;

PIR1=0x01;

TMR1H=0x0B;

TMR1L=0xDC; 

T1CON=0x31;

    TMR1IE = 1;

TMR1IF = 0;

//  T1CON=0x01;

}

 

 

void Init_Controller()

{

  cnt=100;

    TRISC  = 0x80; //RX port configured as input

PORTC  = 0x80;

TRISB=0X00;

PORTB = 0X00;

TRISA=0X00; 

    PORTA=0X00;

    ANSELH=0x00;

ADCON0 = 0b00000000;

ANSEL = 0b00000000;

Timer1_Interrupt();

    LED=0;

 

}

 

//Below code make Ton and Toff time in equal Interval

 

 

void interrupt isr(void)

{

if(TMR1IF==1)

{

 

                    //EA60=45ms CB20 =107ms  

           TMR1H=0xEA; //load the time value(0x0BDC) for 100ms delay

TMR1L=0x60; //Timer1 Interrupt for 65000

TMR1IF=0; // Clear timer interrupt flag

       Dgt++;

           if(  Dgt>=10)

                  {

                   //  LED = !LED; 

                   

                  } 

                  

          

}      

              

  }  

 

 

 

 

 

void Serial_1_Init()

{ 

 

 /* BAUDCTL=0b01001000; //16bit baudrate has used

INTCON = 0b00000000;

    RCIE=1;

RCIF=0;

     CCP1IE=1;

    RCSTA=0b10010000;

    SPBRG = 0x81;

    SPBRGH= 0x00; // 9600 Baud Rate for 64Mhz

TXSTA=0b00100010; // Low Speed mode 

    */

  SPBRG = 32; //9600 baud rate 8Mhz

   RCSTA=0b10010000;

 RCSTA=0b10010000;

  TXEN  = 1;

  BRGH  = 0;

  TXIE  = 0;

  SYNC=0;

  RCSTA = 0;

  SPEN  = 1;

  RX9   = 0;

  CREN  = 1;

 

   

 

}

 

 

void EUSART_Initialize(void)

{

    // disable interrupts before changing states

    RCIE = 0;

    TXIE = 0;

    BAUDCTL=0X09; //16bit baudrate has used

 

    // SPEN enabled; RX9 8-bit; CREN enabled; ADDEN disabled; SREN disabled; 

    RCSTA = 0x90;

 

    // TX9 8-bit; TX9D 0; SENDB sync_break_complete; TXEN enabled; SYNC asynchronous; BRGH hi_speed; CSRC slave; 

    TXSTA = 0x22;

 

    SPBRG=81;

 

SPBRGH=00;

RCIE = 1;

}

 

 

void main(void)

  {

 

             Init_Controller();

            Serial_1_Init();

       //UART_Init(9600);

    /* GIE=1;

 PEIE=1;

 TMR1IE=1; */

 

   

 

while(1)

{

 

    Send_string_uart1("hello");

 

 

 

}

 

 

}

 

 

 

[Abhishek]

you need to provide delays in ISR routines, otherwise this woon't work

[Author]

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