UART.rar_UART通信

#include<p18f452.h> #include<delays.h> #pragma config OSC=HS #pragma config WDT=OFF #pragma config LVP=OFF #define EN PORTBbits.RB3 #define RW PORTBbits.RB4 #define RS PORTBbits.RB5 #define STA PORTDbits.RD7 void busy(void); void delay(int n); void LCD1602_Init(void); void write_cmd(unsigned char m); void write_data(unsigned char x,unsigned char y,unsigned char k); //异步发送 void UART_send_init(void) { TXSTA=0x00; RCSTAbits.SPEN=1; SPBRG=25; //异步模式，波特率设置为2400 } //异步接收 void UART_rec_init(void) { TXSTA=0x00; RCSTAbits.SPEN=1; RCSTAbits.CREN=1; //异步接受，允许连续接收字节 SPBRG=25; //异步模式，波特率设置为2400 } void main() { int num=1,flag=1; TRISC|=0x80; TRISC&=0xbf; TRISD=0; PORTD=0; TRISB&=0x01; TRISB|=0x01; LCD1602_Init(); busy(); while(1) { while(flag==1) { UART_send_init(); TXSTAbits.TXEN=1; TXREG=1; //为什么没有这条指令就不能传送数据？照理说TXREG为空时TXUF位为1，进入死循环后就给TXREG赋值的？ while(flag==1) { if(PIR1bits.TXIF==1) { TXREG=num; num++; while(PIR1bits.TXIF==1); } if(num==256)num=0; if(PORTBbits.RB0==0) { flag=1-flag; while(PORTBbits.RB0==0); } } } while(flag==0) { UART_rec_init(); while(flag==0) { if(PIR1bits.RCIF==1) { num=RCREG; } write_data(1,0,'1'+num); if(PORTBbits.RB0==0) { flag=1-flag; while(PORTBbits.RB0==0); } } } } } void busy(void) { TRISDbits.TRISD7=1; RS=0; RW=1; EN=1; while(STA==1); EN=0; TRISDbits.TRISD7=0; } void LCD1602_Init(void) { Delay1KTCYx(15); write_cmd(0x38); Delay1KTCYx(5); write_cmd(0x38); Delay1KTCYx(5); write_cmd(0x38); write_cmd(0x38); write_cmd(0x08); write_cmd(0x01); write_cmd(0x06); write_cmd(0x0c); } void write_cmd(unsigned char m) { busy(); RS=0; RW=0; PORTD=m; EN=1; Delay1KTCYx(2); EN=0; } void write_data(unsigned char x,unsigned char y,unsigned char k) { x&=0x0f; y&=0x01; if(y==0x00)write_cmd(x|0x80); else write_cmd((x+0x40)|0x80); busy(); RS=1; RW=0; PORTD=k; EN=1; Delay1KTCYx(2); EN=0; } /* void UART_init(void) { TRISC|=0x80; TRISC&=0xbf; TXSTA=0x90; RCSTAbits.SPEN=1; SPBRG=103; //同步模式下设置波特率为9600 // TXREG=0xff; } void main() { int num=1; UART_init(); TXSTAbits.TXEN=1; // TXREG=1; while(1) { if(PIR1bits.TXIF==1) { TXREG=num++; while(PIR1bits.TXIF==1); } if(num==256)num=0; } } */