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1 Introduction

1.1 integrated infrared receiver
1.2 IR remote control

2. The common method
3. Experiment
4. Summary

1 Introduction

Infrared communication using infrared light is a data transmission coding wireless communication system, is currently very widely used. The common life of the TV remote control, air conditioning, remote control, DVD remote control (now estimated to be old as the hills), both use an infrared remote control. Infrared remote control, mainly integrated infrared receiver and infrared remote control.

1.1 integrated infrared receiver

Internal integrated receiver integrated infrared receiver circuit. It can receive an infrared signal and restore a waveform signal transmitting end. Integrated receiver are commonly used infrared signal of 38KHz.

1.2 IR remote control

Take the following experiment remote control

Each has its own coding key, press the button, it will send the corresponding coded infrared waves. Most of the NEC code.

To use an infrared remote control, infrared remote control we use third-party libraries - irRemote (if it is 8266, please use IRremoteESP8266 library).

2. The common method

Here are some IRremote library
1) IRrecv class for receiving infrared signals and decode. Before use to instantiate a class object.

IRrecv (recvpin) constructor recvpin connected to the receiving head pin
enableIRIn () to initialize the decoding IR
decode () checks whether the received encoded
resume () receives the next encoded

3. Experiment

Experiment content : An infrared remote control signal input, displays the corresponding symbols;

Experiment code :

/**
* @Desc  测试红外通信
* @author 单片机菜鸟
* @Date  2016/12/29
* 
*/
#include <IRremote.h>
 
#define MAX 22
 
int RECV_PIN = 7;      //定义红外接收模块输出口接arduino数字引脚11
  
IRrecv irrecv(RECV_PIN);
decode_results results;
//Car mp3编码
unsigned long rremote_code[MAX] = {
    0xFFA25D,0xFF629D,0xFFE21D,//CH- CH CH+
    0xFF22DD,0xFF02FD,0xFFC23D,//PREV NEXT PLAY
    0xFFE01F,0xFFA857,0xFF906F,//VOL- VOL+ EQ
    0xFF6897,0xFF9867,0xFFB04F,// 0 100+ 200+
    0xFF30CF,0xFF18E7,0xFF7A85,// 1  2  3
    0xFF10EF,0xFF38C7,0xFF5AA5,// 4  5  6
    0xFF42BD,0xFF4AB5,0xFF52AD, // 7  8  9
    0xFFFFFFFF//长按
};
 
//Car mp3对应的字符串
String rremote_string[MAX] = {
   "CH-","CH","CH+",
   "PREV","NEXT","PLAY/PAUSE",
   "VOL-","VOL+","EQ",
   "0","100+","200+",
   "1","2","3",
   "4","5","6",
   "7","8","9",
   "longPress"
};
  
void setup()
{
  Serial.begin(9600);
  irrecv.enableIRIn(); //初始化红外遥控
}
  
void loop() {
  if (irrecv.decode(&results)) {
    //打印字符串
    String codeString = getRremoteString(results.value);
    if(codeString.length()!=0)
      Serial.println(codeString);
    irrecv.resume(); // 接收下一个值
  }
}
 
/**
* 解析红外编码并返回对应的字符串
*/
String getRremoteString(unsigned long code){
  String rremotestring = "";
  int i = 0;
  for(i = 0;i<MAX-1;i++){
    if(code == rremote_code){
      break;  
    }
  }
  //过滤掉长按
  if(i==MAX-1) return "";
  else return rremote_string;
}

The results :

4. Summary

By using this library we can resolve to a specific key code, so that we can do things that we want to do this based on the infrared remote control (you can look at what I wrote Bluetooth colorful lights posts).

Arduino study notes ⑧ infrared communication