Simulate serial port to realize MCU IO port

Use EBOX to send data to our power line debugging module, but a control interface is required, but EBOX does not provide it, so we have to use MCU as a server.

Generally, microcontrollers only have one serial port, so one must be simulated.

 

/*

  sbit TXD1 = P1^4; //define p14 as the analog transmit port

  sbit RXD1 = P1^2; //define p12 as the analog recieve port

*/

#include "REG52.H"

#define uint unsigned int

#define uchar unsigned char

#include

 void WaitTF0(void);

 

 void TIMEINI(void) //counter initial

  {

    TMOD=0x02;

    TH0=0xA0; , //9600 BPS

       TL0=TH0;

       TR0=1;

       TF0=0;

   }

 

 

   void WByte(uchar input) // send function

   {

         uchar i=8;

              TR0=1;

              TXD1=0; //begin bit

              WaitTF0();

                                                 //send the Byte

           while(i--)

            {

                     TXD1=input&0x01; //send Byte from low bit to high bit

 

                      WaitTF0();                               

                      input=input>>1; //right shift

          }

               TXD1=1; //stop bit

              WaitTF0();

              TR0=0; //stop the counter

   }

   

       uchar RByte() //the recieve function

   {

         uchar Output=0;

          uchar i=8;

                                      

               while(RXD1);                          

                    i=i;

                     i=i;

                     i=i;

                     i=i;

                     i=i;

                     i=i;

                     i=i;

                     TR0=1; //The counter starts working

                  WaitTF0();

                                                       

           while(i--) // Receive 8 bits of data

            {

                      Output>>=1;

                      if(RXD1)Output=Output|0x80; //recieve from the high bit to low bit

             WaitTF0();

          }

      

              TR0=0;

               return Output;

   }

 

  void WaitTF0(void) //check the counter

  {

             while(!TF0);

             TF0=0;

  }