c - PIC 打印垃圾字符而不是预期字符

Question

我想用我的PIC18F4550、蓝牙模块HC-06和电脑做一个简单的测试。我的意思是，我想使用蓝牙模块将一个简单的字符从 PIC 发送到 PC。

它应该在终端中出现一个“A”，但出现的是十六进制的 F8(ASCII:看起来像一个内部有斜杠的“o”)。我尝试使用 printf、puts 或 fputs 来代替，但 F8 仍然显示加上这个符号“€”。

接下来是我的代码和原理图...有人可以帮助我找到我的错误吗？

(我正在使用 RCom Serial 或 CoolTerminal)

#include <18f4550.h>
#include <stdio.h> 

#fuses XT, NOWDT, NOPROTECT, PUT, BROWNOUT, NOLVP, NOCPD, NOWRT

#use delay (clock=4000000)

#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, bits=8, parity=N)

void main() {
    while (1) {
        printf("A");
    }
}

Answer 1

这是在 UART 端口上打印调试消息的通用代码。注意:

#include <xc.h>
// Use your uC header file
#include <pic16f877a.h>
#include <stdio.h>
#include <string.h>

#define _XTAL_FREQ 20000000
#define FREQ _XTAL_FREQ
#define baud 9600
#define spbrg_value (((FREQ/64)/baud)-1)

unsigned char UARTdata;

void serial_init()
{
    SPBRG=spbrg_value;
    //SPBRG=31;
    //TXSTAbits.TXEN = 1;
    //CSRC: Clock Source Select bit            0
    //TX9 : 9-bit Transmit Enable bit          0
    //TXEN: Transmit Enable                    0  
    //SYNC: EUSART Mode Select bit             0
    //SENDB: Send Break Character bit          0
    //BRGH: High Baud Rate Select bit          0
    //TRMT: Transmit Shift Register Status bit 1
    //TX9D: Ninth bit of Transmit Data         0
    TXSTA=0x20;

    //RCSTAbits.SPEN = 1;
    //RCSTAbits.CREN = 1    
    //bit 7 SPEN: Serial Port Enable bit        1
    //bit 6 RX9: 9-bit Receive Enable bit       0
    //bit 5 SREN: Single Receive Enable bit     0
    //bit 4 CREN: Continuous Receive Enable bit 1
    //bit 3 ADDEN: Address Detect Enable bit    0
    //bit 2 FERR: Framing Error bit             0
    //bit 1 OERR: Overrun Error bit             0
    //bit 0 RX9D: 9th bit of Received Data      0
    RCSTA=0x90;
    //Setting 
    TRISCbits.TRISC6=0;
    TRISCbits.TRISC7=1;
}

void putch(unsigned char UARTdata)
{
    while( ! TXIF)
        continue;
    TXREG = UARTdata;
}



// CONFIG
#pragma config FOSC  = HS      // Oscillator Selection bits (HS oscillator)
#pragma config WDTE  = OFF     // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF    // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = ON    // Brown-out Reset Enable bit (BOR disabled)
#pragma config LVP   = OFF      // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)
#pragma config CPD   = OFF      // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off)
#pragma config WRT   = OFF      // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control)
#pragma config CP    = OFF       // Flash Program Memory Code Protection bit (Code protection off)


void main()
{
  serial_init();

  printf("DRIVER Enjoy Direct print method!");

  while(1)
  {

    __delay_ms(1000);
    printf("A");
    __delay_ms(1000);     

  }                    
}