我正在尝试从 pic16f887 传输一个字符“a”并在终端上查看结果,但我得到的只是一个问号(使用 USART 终端),或者什么都没有(腻子,超级终端)。我对 C 不是很好,因为我只是一个初学者,但我真的需要让它为我的学校项目工作。我尝试了很多我在互联网上找到的代码,我确实设法收到了来自终端的字符,比如说,打开一个 LED,但我无法让它发送任何东西。我有一种强烈的感觉,它在代码的某个地方。我使用 MPLAB 和 Hi-Tech C 编译器来构建项目。这里是:
unsigned char cUART_char;
unsigned char cUART_data_flg;
void init_uart(void);
void UART_putc(unsigned char c);
void InterruptHandlerLow ();
void main()
{
TRISA = 0;
PORTA = 0;
TRISB = 0;
PORTB = 0;
TRISD = 0;
PORTD = 0;
ANSELH = 0;
init_uart();
while (1)
{
if (cUART_data_flg==1)
{
UART_putc(cUART_char);
cUART_data_flg=0;
}
}
}
void InterruptHandlerLow ()
{
if (RCIF==1)//is interrupt occured by EUSART receive?,
//then RCREG is full we have new data (cleared when RCREG is read)
{
if(RCSTA&0x06) //more efficient way than following commented method to check for reception error
//if(RCSTAbits.FERR==1 || RCSTAbits.OERR==1 )
{
CREN=0; //Overrun error (can be cleared by clearing bit CREN)
cUART_char=RCREG; //clear Framing error
CREN=1;
}
else
{
cUART_char = RCREG; // read new data into variable
cUART_data_flg = 1; // new data received. so enable flg
}
}
}
void init_uart(void) // init UART module for 9600bps boud, start bit 1, stopbit 1, parity NONE
{
// init data receive flag to zero (no data)
TRISC7=1; //Make UART RX pin input
TRISC6=0; //Make UART TX pin output
SYNC = 0; // enables for asynchronous EUART
SPEN = 1; // enables EUSART and sets TX (RC6) as output; ANSEL must be cleared if shared with analog I/O
CREN = 1;
TX9 = 0; // 8bit mode
RX9 = 0;
TXEN = 1; // enables Transmitter
BRGH = 1; // baud rate select
BRG16 = 0;
SPBRG = 25; //baud rate select 9600@4Mhz
SPBRGH = 0;
RCIE=1; // receive interrupt enable
GIE=1; // global interrupt enable
PEIE=1 ; // Peripheral Interrupt Enable bit
}
void UART_putc(unsigned char c)
{
TXEN=0;// disable transmission
TXREG=0x61; // load txreg with data
TXEN=1; // enable transmission
while(TRMT==0) // wait here till transmit complete
{
}
}
请如果有人在此代码中看到问题(或更多问题),请帮我解决这个问题;)哦,当按下连接到 TX 引脚(RC6)的按钮时,我正在传输..