AVR_M8单片机串口控制应用程序

#include #include #include "Io_define.h"unsigned char RX_data[4]={0};       //串口接收的数据unsigned char keyb_state=0;unsigned char keyc_state=0;unsigned char RX_counter=0;         //串口接收到的字节数计数器void UART_init        (void);void putchar          (unsigned char c);void puts             (unsigned char *s);void UART_rx          (void);void delay_nms        (unsigned int n);void Key_control      (unsigned char comm);void Read_Pin         (void);void putchar(unsigned char c)        //字符输出函数  {     while (!(UCSRA&(1 << UDRE)));   //判断上次发送有没有完成     UDR = c;     }#pragma interrupt_handler UART_rx: iv_USART_RXvoid UART_rx(void)                   //串口接收中断函数  {     RX_data[RX_counter] = UDR;         if (RX_data[RX_counter]=='s')       {          RX_data[0]=RX_data[RX_counter];          RX_counter=0;       }         RX_counter++;                   //接收的字节数计数  }void puts(unsigned char *s)          //字符串发送函数  {     while (*s)       {          putchar(*s);          s++;       }  } void UART_init(void)  {     UCSRB = BIT(RXCIE)| BIT(RXEN) |BIT(TXEN);   //允许串口发送和接收，并响应接收完成中断     UBRR = 51;                                  //时钟8Mhz，波特率9600     UCSRC = BIT(URSEL)|BIT(UCSZ1)|BIT(UCSZ0);   //8位数据＋1位stop位  } void main(void)  {     //unsigned char keyb_state=0;     //unsigned char keyc_state=0;     unsigned char i=0;         OSCCAL=0xa3;         DDRB  = 0B11000111;       //初始化继电器控制端口          PORTB = 0B00000000;     DDRC  = 0B00111111;     PORTC = 0B00000000;     DDRD  = 0B10000000;     PORTD = 0B00000000;         DDRB |= 0b00111000;           //初始化键盘接口，行为低电平       PORTB&= 0b11000111;         DDRD &= ~0b01111000;            //列为高电平     PORTD|= 0b01111000;        DDRD  &= ~BIT(2);         //设置INT0为输入，高电平状态     PORTD |= BIT(2);     GICR  |= BIT(INT0);        //允许INT0外部低电平中断         UART_init();         SEI();         while (1)       {         if (RX_counter==4)           {                 RX_counter=0;             if (RX_data[3] == 't')     //接收到PC机发的状态请求指令，则发送               {                        //控制板的key状态数据给PC                 putchar(0);            //控制板地址码                 delay_nms(10);                 putchar(keyb_state);                 delay_nms(10);                 putchar(keyc_state);                 delay_nms(10);                 putchar('t');          //状态数据标志位                 delay_nms(10);               }             else             if ((RX_data[0] == 's')&&(RX_data[3] == 'p'))   //检验指令格式是否正确               {                  if ((RX_data[1] == 'u') &&(RX_data[2]=='0'))//是否是软件升级指令                   {                     //puts("upready");                     asm("jmp 0xe00");                   }                 else                  if (RX_data[1]=='0')                        //地址码是否正确                   {                      Key_control(RX_data[2]);                                  }               }          }     }  } void Key_control(unsigned char comm)  {     CLI();     switch (comm)       {         case '0':  key0  ^= key0_open;  break;         case '1':  key1  ^= key1_open;  break;         case '2':  key2  ^= key2_open;  break;  case '3':  key3  ^= key3_open;  break;         case '4':  key4  ^= key4_open;  break;         case '5':  key5  ^= key5_open;  break;         case '6':  key6  ^= key6_open;  break;         case '7':  key7  ^= key7_open;  break;         case '8':  key8  ^= key8_open;  break;         case '9':  key9  ^= key9_open;  break;         case ':':  key10 ^= key10_open; break;         case ';':  key11 ^= key11_open; break;          case 'a': {                    PORTB |= 0B11000111;                    PORTC |= 0B00111111;                    PORTD |= 0B10000000;                  }  break;          case 'b': {                       PORTB &= 0B00111000;                    PORTC &= 0B11000000;                    PORTD &= 0B01111111;                  }  break;                                             }           Read_Pin();      putchar(0);           //发送控制板地址码和key状态数据      delay_nms(10);      putchar(keyb_state);      delay_nms(10);      putchar(keyc_state);      delay_nms(10);      putchar('t');      delay_nms(10);      SEI();  }void Read_Pin(void)  {    asm("nop");    keyb_state = ((PINB & 0B11000111)|((PINC & 0B00110000)>>1)|                  ((PIND & 0B10000000)>>2));    keyc_state = (PINC & 0B00001111);  }