m8单片机串口通讯程序

ID:1104531 · 发表于 2024-1-11 21:08

个人认为，AVR系列的串口使用还是比较容易出错，如果采用传统的查询方式太耗系统时间，而且现在关于AVR的教材大多给你的是查询发送方式，中断接收方式。
本例子是采用中断接收，中断发送方式。希望对大家有所帮助。

//ICC-AVR
// Target : M8
// Crystal: 4.0000Mhz

#include <iom8v.h>
#include <macros.h>

#define DISABLE_UARTTX()       UCSRB&=~BIT(TXCIE)
#define ABLE_UARTTX()             UCSRA|=BIT(TXC);UCSRB|=BIT(TXCIE)

unsigned char ucRecv;
unsigned char ucRecvOk;

unsigned char ucSendData[8]="Recv OK!";
unsigned char ucComSendCnt,ucComSendPtr;

void InitPort(void)
{
      PORTB = 0xFF;
      DDRB  = 0x00;
      PORTC = 0x7F; //m103 output only
      DDRC  = 0x00;
      PORTD = 0xFE;
      DDRD  = 0x02;
}

//UART0 initialize
// desired baud rate: 2400
// actual: baud rate:2404 (0.2%)
void InitUart0(void)
{
      UCSRB = 0x00; //disable while setting baud rate
      UCSRA = 0x00;
      UCSRC = BIT(URSEL) | 0x06;
      UBRRL = 0x67; //set baud rate lo
      UBRRH = 0x00; //set baud rate hi
      UCSRB = 0x98;
}

#pragma interrupt_handler uart0_rx_isr:iv_USART0_RXC
void uart0_rx_isr(void)
{
      unsigned char ucTmp;
//uart has received a character in UDR
      ucTmp=UDR;
      if (ucTmp=='A')
      {
            ucRecv=ucTmp;
            ucRecvOk=0x01;
      }
}

#pragma interrupt_handler uart0_tx_isr:iv_USART0_TXC
void uart0_tx_isr(void)
{
//character has been transmitted
      if (ucComSendCnt!=0)
      {
               ucComSendPtr+=1;
               UDR=ucSendData[ucComSendPtr];
            ucComSendCnt-=1;
      }else
      {
            //PORTB&=~BIT(PB_COM_LED);                                     //串口指示灯灭
            DISABLE_UARTTX();
            //PORTB^=BIT(PB_COM_LED);                                     //串口指示灯灭
      }
}

//call this routine to initialize all peripherals
void InitMcu(void)
{
//stop errant interrupts until set up
      CLI();                      //disable all interrupts
      InitPort();
      InitUart0();

      MCUCR = 0x00;
      GICR  = 0x00;
      TIMSK = 0x00;       //timer interrupt sources
      SEI();                      //re-enable interrupts
                                       //all peripherals are now initialized
}

void main(void)
{
      unsigned char i;
      InitMcu();
      while(1)
      {
            if (ucRecvOk==0x01)
            {
                     CLI();
                     ucRecvOk=0;
                     SEI();

                     ucComSendCnt=7;
                     ucComSendPtr=0;
                     ABLE_UARTTX();
                     UDR=ucSendData[0];
            }
      }
}

ID:229502 · 发表于 2024-2-11 21:18

楼主能否有个注解，对初学者更友好

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m8单片机串口通讯程序

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