UART sending wrong characters on pic18 - send

Question

I'm trying to simply send characters trough my UART Interface by calling the funktion: UART_Write_Text("hello");
this is the code executed in the the uart.c file:
void UART_Init(void)
{
//115200bps deafult value for RN4678
BRGH = 0; //Setting High Baud Rat
BRG16 = 0; //8-Bit mode
SPBRG = 8; //Writing SPBRG Register
TXSTAbits.SYNC = 0; //Setting Asynchronous Mode, ie UART
RCSTAbits.SPEN = 1; //Enables Serial Port
RCSTAbits.CREN = 1; //Enables Reception
TXSTAbits.TXEN = 1; //Enables Transmission
}
/******************************************************************************/
//-----UART write byte
/******************************************************************************/
void UART_Write(char data)
{
while(!TRMT);
TXREG = data;
}
/******************************************************************************/
//-----UART check tx queue
/******************************************************************************/
char UART_TX_Empty(void)
{
return TRMT;
}
/******************************************************************************/
//-----UART write string
/******************************************************************************/
void UART_Write_Text(char *text)
{
for(int i=0; text[i]!='\0' || text[i] !=0x00; i++){
UART_Write(text[i]);
}
UART_Write('\n');
}
/******************************************************************************/
//-----UART data ready to read
/******************************************************************************/
char UART_Data_Ready(void)
{
return RCIF;
}
/******************************************************************************/
//-----UART read byte
/******************************************************************************/
char UART_Read(void)
{
while(!RCIF);
return RCREG;
}
/******************************************************************************/
//-----UART read string
/******************************************************************************/
void UART_Read_Text(char *Output, unsigned int length)
{
unsigned int i;
for(int i=0;i<length;i++)
Output[i] = UART_Read();
}
Now when I'm debugging it, I see that it writes the wright charakters into the TXREG. At the end it sended the following characters: 'h', 'e', 'l', 'l', 'o', '\n'.
I send them to the bluetooth module RN4678 with a baud rate of 115200bps which is also the default baud rate of the BT module. However when I read the sended character on my phone with a Bluetooth terminal i get only some characters wright and the other ones are questionmarks, so it doesn't recognise them (not always the same character unrecognised).
I already experimented with the baud rate, but it looks like its the right value I writed into the SPBRG.
I'm also polling the TRMT so there shouldn't be any collisions...
Someone knows what I'm doing wrong?

Answer 1

#include "Configuration_bits.h"
#include <xc.h>
#include <stdio.h>
#include <p18f67k22.h>
#include <string.h>
#include <stdlib.h>
#define _XTAL_FREQ 16000000
void UART_Init_1(){
TRISCbits.TRISC6=1; // TX1 Pin-31
TRISCbits.TRISC7=1; // RX1 Pin-32
RC1IE=1;
SPBRG1=34; // Baud Rate 115200
BAUDCON1bits.BRG16=1;
TXSTA1bits.BRGH=1;
//TXSTA 1 Register
TXSTA1bits.TX9=0; // 8-bit transmission
TXSTA1bits.TXEN=0;
TXSTA1bits.TXEN=1; // Transmit is enabled
TXSTA1bits.SYNC=0; // Asynchronous mode
TXSTA1bits.TRMT=1; // Transmit Shift Register Status bit
//RXSTA 1 Register
RCSTA1bits.SPEN=1; // Serial Port Enable bit
RCSTA1bits.RX9=0; // 8-bit reception
RCSTA1bits.CREN=1; // Continuous Receive Enable bit
}
void UART_Tx_1(unsigned char z[])
{
unsigned int uart_tx1=0;
while(z[uart_tx1]!='\0')
{
while(!TX1IF);
TXREG1=z[uart_tx1];
uart_tx1++;
}
}
void UART_Rx_1()
{
string_rx1[uart_rx1]=RCREG1;
uart_rx1++;
}
void interrupt ISR(void)
{
if(RC1IF && RC1IE) // UART_1
{
}
}
void main(void)
{
System_Initialization();
UART_Init_1();
while(1)
{
UART_Tx_1("HELLO\r\n"); // Transmit Hello
}
}