Single chip infrared transmitting and receiving circuit

The microcontroller source program is as follows:

/*******************************************************************

        Work: Infrared Emission

  Microcontroller: STC89C52RC

    Crystal: 12M

Compilation environment: Keil uVision4 V9.00

*******************************************************************/

//

// Emitting pin (connected to the PNP transistor B)

//PNP transistor e-pole connected to 2Ω resistor, c-pole connected to infrared emitting tube

#include

#include

#define uchar unsigned char

#define uint unsigned int

#define SBM 0x80 //Identification code

#define m9 (65536-9000) //about 9mS

#define m4_5 (65536-4500) //about 4.5mS

#define m1_6 (65536-1630) //about 1.65mS

#define m_65 (65536-580) //about 0.65mS

#define m_56 (65536-560) //about 0.56mS

#define m40 (65536-40000) //about 40mS

#define m56 (65536-56000) //56mS

#define m2_25 (65536-2250) //about 2.25mS

sbit IR = P3^6; //Define the emission pin (connected to the base of the PNP transistor)

sbit LED = P3^7; //Transmit indicator light

uchar KEY(void);

void SanZhuan(void);

void ZZ(uchar x);

void Z0(uchar temp);

void TT0(bit BT,uint x);

void YS(uchar time);

/*┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈

Function: Main function

┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈*/

void main(void)

{

  TMOD = 0x01; //T0 16-bit working mode

  IR=1; //The transmitting port is normally high level

  while(1)

  {

   SanZhuan();

  }

}

/*******************************************************************

Function: 4×4 matrix keyboard

                           Key-value                    

P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7

│ │ │ │ │ │ │ │ ┃

│ │ │ └────13 14 15 16 ┃   

│ │ └─────────9 10 11 12 ┃   

│ └──────────────5 6 7 8 ┃   

└────────────────────1 2 3 4 ┃  

*******************************************************************/

uchar KEY(void)

{

uchar H,L; //row value, column value

H=0;

L=0;

P1 = 0xf0; //Set the keyboard port row value to 1 and the column value to 0

if(P1!= 0xf0) //Check if a key is pressed, if so, hangval must not be 0x0f

   {

    YS(10); //key debounce, delay 10 milliseconds

    if(P1!=0xf0) //A key is pressed

      {

       H = P1&0xf0; //After pressing the key, get the row flag of the key and assign the row flag to hangval

       P1 = 0x0f; //Flip keyboard interface output

       L = P1&0x0f; //Get the column flag

      }

        return (H+L);

   }

  return 0;

}

/*******************************************************************

Function: Scatter program

Entry parameter: v

//

// 13 14 15 16

// 9 10 11 12

// 5 6 7 8

// 1 2 3 4

*******************************************************************/

void SanZhuan(void)

{

uchar v;

v = KEY();

switch(v)

{

  case 0x77:ZZ(0x01);v=0;break; //" "

  case 0xb7:ZZ(0x02);v=0;break; //" "

  case 0xd7:ZZ(0x03);v=0;break; //" "

  case 0xe7:ZZ(0x04);v=0;break; //" "

  case 0x7b:ZZ(0x05);v=0;break; //" "

  case 0xbb:ZZ(0x06);v=0;break; //" "

  case 0xdb:ZZ(0x07);v=0;break; //" "

  case 0xeb:ZZ(0x08);v=0;break; //" "

  case 0x7d:ZZ(0x09);v=0;break; //" "

  case 0xbd:ZZ(0x10);v=0;break; //" "

  case 0xdd:ZZ(0x11);v=0;break; //" "

  case 0xed:ZZ(0x12);v=0;break; //" "

  case 0x7e:ZZ(0x13);v=0;break; //" "

  case 0xbe:ZZ(0x14);v=0;break; //" "

  case 0xde:ZZ(0x15);v=0;break; //" "

  case 0xee:ZZ(0x16);v=0;break; //" "

  default:v=0;

}

}

/*┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈

Function: Send the main program

┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈*/

void ZZ(uchar x)

{

  TT0(1,m9); //High level 9mS

  TT0(0,m4_5); //Low level 4.5mS

  /*┈ Send 4 frames of data┈*/

  Z0(SBM);                                                                                                                                       

  Z0(~SBM);

  Z0(x);

  Z0(~x);

  /*┈┈ End code┈┈*/

  TT0(1,m_65);

  TT0(0,m40);

  /*┈┈ Repeat code┈┈*/

  while(KEY())

   {

        TT0(1,m9);

        TT0(0,m2_25);

        TT0(1,m_56);

        TT0(0,m40);

                TT0(0,m56);

                LED = !LED; //Indicator light                                          

    }

   LED = 1;                    

}

/*┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈

Function: Single frame sending program

Entry parameters: 1 frame of data

┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈*/

void Z0(uchar temp)

{

  uchar v;

  for (v=0;v<8;v++) //Loop 8 times shift

       {     

                 TT0(1,m_65); //High level 0.65mS         

                         if(temp&0x01) TT0(0,m1_6); //Send the lowest bit

                         else TT0(0,m_56);     

                         temp >>= 1; //Shift right one bit

        }   

}

/*┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈

Function: 38KHz pulse transmission + delay program

Entry parameters: (whether to emit pulses, delay of about x (uS))

┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈*/

void TT0(bit BT,uint x)

{

  TH0 = x>>8; // Input T0 initial value

  TL0 = x;

  TF0=0; //clear to 0

  TR0=1; //Start timer 0

  if(BT == 0) while(!TF0); //When BT=0, 38KHz pulse is not emitted and only delay is performed; when BT=1, 38KHz pulse is emitted and delayed;

  else while(1) //38KHz pulse, duty cycle 5:26

         {

                  IR = 0;

                  if(TF0)break;

               if(TF0)break;

                  IR = 1;

                if(TF0)break;

                 if(TF0)break;

……………………