前言
本篇文章属于STC89C52单片机（以下简称单片机）的学习笔记，来源于B站教学视频。下面是这位up主的视频链接。本文为个人学习笔记，只能做参考，细节方面建议观看视频，肯定受益匪浅。
[1-1] 课程简介_哔哩哔哩_bilibili
一、红外遥控介绍
二、硬件电路
其中的三极管是低电平导通，红外信号发送时要进行调制，接受时要进行解调，OUT输出的就是解调后的方波，OUT要接到单片机的外部中断上，保证单片机能捕捉到这个信号
三、基本发送与接受
四、NEC编码
注意Data的逻辑0和逻辑1，不是单纯的高低电平，而是高低电平的组合，Repeat信号是当一个按键一直处于按下状态，就重复操作这个按键
五、遥控器键码
六、51单片机的外部中断
七、外部中断寄存器
八、实例一（红外遥控）
主要有Timer0.c 和 Int0.c 和IR.c 和 main.c
1.Timer0.c模块，主要用于计时，来判断信号类型
#include <REGX52.H>void Timer0_Init(void)
{TMOD &= 0xF0; //设置定时器模式TMOD |= 0x01; //设置定时器模式TL0 = 0; //设置定时初值TH0 = 0; //设置定时初值TF0 = 0; //清除TF0标志TR0 = 0; //定时器0不计时
}void Timer0_SetCounter(unsigned char Value)
{TH0=Value/256;TL0=Value%256;
}unsigned int Timer0_GetCounter(void)
{return (TH0<<8)|TL0;
}void Timer0_Run(unsigned char Flag)
{TR0=Flag;
}2.Int0.c 外部中断模块，使红外遥控的命令处于较高的优先级，保证数据不丢失
#include <REGX52.H>void Int0_Init(void)
{IT0=1;IE0=0;EX0=1;EA=1;PX0=1;
}/*中断函数模板
void Int0_Routine(void) interrupt 0
{}
*/3.IR.c 红外遥控模块 ，解码过程
#include <REGX52.H>
#include "Int0.h"
#include "Timer0.h"unsigned int IR_Time;
unsigned char IR_State;unsigned char IR_Data[4];
unsigned char IR_pData;unsigned char IR_DataFlag;
unsigned char IR_RepeatFlag;
unsigned char IR_Address;
unsigned char IR_Command;void IR_Init(void)
{Timer0_Init();Int0_Init();
}unsigned char IR_GetDataFlag(void)
{if (IR_DataFlag){IR_DataFlag=0;return 1;}return 0;
}unsigned char IR_GetRepeatFlag(void)
{if (IR_RepeatFlag){IR_RepeatFlag=0;return 1;}return 0;
}unsigned char IR_GetAddress(void)
{return IR_Address;
}unsigned char IR_GetCommand(void)
{return IR_Command;
}void Int0_Routine(void) interrupt 0
{if(IR_State==0){Timer0_SetCounter(0);Timer0_Run(1);IR_State=1;}else if (IR_State==1){IR_Time=Timer0_GetCounter();Timer0_SetCounter(0);if (IR_Time>13500-1000 && IR_Time<13500+1000){IR_State=2;}else if (IR_Time>11250-1000 && IR_Time<11250+1000){IR_RepeatFlag=1;Timer0_Run(0);IR_State=0;}else {IR_State=1;}}else if (IR_State==2){IR_Time=Timer0_GetCounter();Timer0_SetCounter(0);if (IR_Time>1120-500 && IR_Time<1120+500){IR_Data[IR_pData/8]&=~(0x01<<(IR_pData%8));IR_pData++;}else if (IR_Time>2250-500 && IR_Time<2250+500){IR_Data[IR_pData/8]|=(0x01<<(IR_pData%8));IR_pData++;}else{IR_pData=0;IR_State=1;}if (IR_pData>=32){IR_pData=0;if ((IR_Data[0]==~IR_Data[1]) && (IR_Data[2]==~IR_Data[3])){IR_Address=IR_Data[0];IR_Command=IR_Data[2];IR_DataFlag=1;}Timer0_Run(0);IR_State=0;}}}IR.h中定义键码值
#ifndef __IR_H__
#define __IR_H__#define IR_POWER 0x45
#define IR_MODE 0x46
#define IR_MUTE 0x47
#define IR_START_STOP 0x44
#define IR_PREVIOUS 0x40
#define IR_NEXT 0x43
#define IR_EQ 0x07
#define IR_VOL_MINUS 0x15
#define IR_VOL_ADD 0x09
#define IR_0 0x16
#define IR_RPT 0x19
#define IR_USD 0x0D
#define IR_1 0x0C
#define IR_2 0x18
#define IR_3 0x5E
#define IR_4 0x08
#define IR_5 0x1C
#define IR_6 0x5A
#define IR_7 0x42
#define IR_8 0x52
#define IR_9 0x4Avoid IR_Init(void);
unsigned char IR_GetDataFlag(void);
unsigned char IR_GetRepeatFlag(void);
unsigned char IR_GetAddress(void);
unsigned char IR_GetCommand(void);#endif4.main.c 主函数调用模块
#include <REGX52.H>
#include "LCD1602.h"
#include "Delay.h"
#include "IR.h"unsigned char Address;
unsigned char Command;
unsigned char Num;void main()
{LCD_Init();LCD_ShowString(1,1,"ADD");LCD_ShowString(1,6,"CMD");LCD_ShowString(1,11,"Num");LCD_ShowString(2,1,"00");LCD_ShowString(2,6,"00");LCD_ShowString(2,11,"000");IR_Init();while(1){if(IR_GetDataFlag() || IR_GetRepeatFlag()){Address=IR_GetAddress();Command=IR_GetCommand();LCD_ShowHexNum(2,1,Address,2);LCD_ShowHexNum(2,6,Command,2);if (Command==IR_VOL_MINUS){Num--;}if (Command==IR_VOL_ADD){Num++;}LCD_ShowNum(2,11,Num,3);}}
}九、实例二（红外遥控电机调速）
先把电机模块化
Motor.c
#include <REGX52.H>
#include "Timer1.h"sbit Motor=P1^0;unsigned char Counter,Compare;void Motor_Init(void)
{Timer1_Init();
}void Motor_SetSpeed(unsigned char Speed)
{Compare=Speed;
}void Timer1_Rountine() interrupt 3
{TH1=0xFF; TL1=0xA4; Counter++;Counter%=100;if (Counter<Compare){Motor=1;}else{Motor=0;}
}
然后在主程序中应用红外模块和马达模块
main.c
#include <REGX52.H>#include "Nixie.h"
#include "Motor.h"
#include "Timer1.h"
#include "IR.h"unsigned char Command,Speed;void main()
{Motor_Init();IR_Init();while(1){if(IR_GetDataFlag()){Command=IR_GetCommand(); if (Command==IR_0){Speed=0;}if (Command==IR_1){Speed=1;}if (Command==IR_2){Speed=2;}if (Command==IR_3){Speed=3;}switch(Speed){case 0:Motor_SetSpeed(0);break;case 1:Motor_SetSpeed(50);break;case 2:Motor_SetSpeed(75);break;case 3:Motor_SetSpeed(100);break;}}Nixie(1,Speed);}
}
