首页 › Arduino › Digispark红外接收器

smching 发表于 2013-6-1 19:02:33

Digispark红外接收器

之前的红外遥控制作都是使用别人的代码或程序库完全。其中Ken Shirriff 的Arduino红外程序库，更是许多Arduino发烧友使用之设计红外制作。

不过这个适合不同红外协议的Ken Shirriff红外程序库並不适合用在Digispark，因为代码复杂，工作繁重，根本不能置入Digispark。没有办法之下唯有自行研究。

由于不熟悉红外原理，花费了一些时间在网站浏览资料，同时一面阅读资料一面测试，终于大功告成。

了觧一下Digispark自带的红外例子
Digispark自带了一个infrared例子，却没有对红外协议分析，按下任何遥控器按钮，只能触发同一事件。以下例子按下任何按钮，都会点亮LED，一秒后关灯。
int irPin=2;//digital 2 (ATTINT85 pin 7)
int ledPin=0; //digital 0 (ATTINY85 pin 5)

void setup()
{
pinMode(irPin,INPUT);
pinMode(ledPin,OUTPUT);
digitalWrite(0,HIGH);
}

void loop()
{
if(pulseIn(irPin,LOW)) //reads a pulse on a pin
{
   //button pressed
   delay(100);
   digitalWrite(ledPin,HIGH);
   delay(1000);
   digitalWrite(ledPin,LOW);
}
}

代码运用了pulseIn来侦察红外信号。pulseIn是用来侦察谋个引脚的脉冲升高或降低，以便测量其长度，而长度则以微秒（microseconds）计算。

根据以上代码(Sketch)，我设计了以下线路图。




下面例子使用Arduino(不是Digispark)作红外解码，毎一个脉冲的长度将从串行监控器(Serial monitor)显示在屏幕上

int irPin = 2; //IR detector connected to digital 2
const byte BIT_PER_BLOCK = 32;

void setup() {
pinMode(irPin, INPUT);
Serial.begin(9600);
}
void loop() {
int data;
int i;

for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    //Start measuring bits, I only want high pulses
    //you may want to use LOW pulse --> pulseIn(irPin, LOW)
    data = pulseIn(irPin, HIGH);   
}

delay(100);
for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    Serial.println(data);
}
Serial.println("=========");
}

以下是我的红外数据採样


更完整的数据採样



当然你也可以使用Digispark，将获取的红外资料，通过模拟键盘发送数据至电脑，同时打开文本编辑器（如Windows Notepad）来查看数据，但是此方式的显示速度要比使用串行监视慢许多。


#include "DigiKeyboard.h"
int irPin = 2; //IR receiver wired to digital 2 (ATTINY pin7)
const byte BIT_PER_BLOCK = 32;
void setup() {
pinMode(irPin, INPUT);
Serial.begin(9600);
}
void loop() {
int data;
int i;

// this is generally not necessary but with some older systems it seems to
// prevent missing the first character after a delay:
DigiKeyboard.sendKeyStroke(0);

for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    //Start measuring bits, I only want high pulses
    //you may want to use LOW pulse --> pulseIn(irPin, LOW)
    data = pulseIn(irPin, HIGH);
}

delay(100);
for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    DigiKeyboard.println(data);
}
DigiKeyboard.println("=========");
}


这里发放完整且可以运行的源代码(针对NEC协议)，如想要知道如何工作及分析其他的红外协议，去浏览我的个人网站吧！

以下代码把处理了的NEC红外信号，转换成整数(decimal)，通过模拟键盘发送数据至电脑，从而显示各按钮的值。#include "DigiKeyboard.h"
int irPin = 2; //Sensor pin connect to digital pin2 (ATINY85 pin7)
int start_bit = 2200; //Start bit threshold (Microseconds)
int bin_1 = 1000; //Binary 1 threshold (Microseconds)
int bin_0 = 400; //Binary 0 threshold (Microseconds)
const byte BIT_PER_BLOCK = 32;

void setup() {
pinMode(irPin, INPUT);
}

void loop() {
DigiKeyboard.update(); //keep on updating the keyboard
// this is generally not necessary but with some older systems it seems to
// prevent missing the first character after a delay:
DigiKeyboard.sendKeyStroke(0);

int key = getIRKey();      //Fetch the key

if(key != 0) //Ignore keys that are zero
{
    DigiKeyboard.print("=>");//uncomment this if you want to
    DigiKeyboard.println(key); //print out the value of the button
}
}

/////////////////////////////////////////////////////////////
// decode infrared signal
/////////////////////////////////////////////////////////////
int getIRKey() {
int data;
int i;
while(pulseIn(irPin, HIGH) < start_bit); //Wait for a start bit

for(i = 0 ; i < BIT_PER_BLOCK ; i++)
    data = pulseIn(irPin, HIGH); //Start measuring bits, I only want HIGH pulses

delay(100);
for(i = 0 ; i < BIT_PER_BLOCK ; i++) //Parse them
{   
    if(data > bin_1) //is it a 1?
      data = 1;
    else if(data > bin_0) //is it a 0?
      data = 0;
    else
      return -1; //Flag the data as invalid; Return -1 on invalid data
}
//based on NEC protocol, command data started from bit 16
//and end with bit 24 (8 bits long)
int result = 0;
for(i = 16 ; i < 24; i++) {
    DigiKeyboard.print(data); //print out the value of button in binary form
    if(data == 1) result |= (1<<i-16); convert="" data="" bits="" to="" integer
}
return result; //Return key number
}


以下代码用于遥控电脑。我用来遥控点唱。此代码占用了4408 Byte Flash Memory，可以使用的Flash Memory剩下1604 Byte 。
#include "DigiKeyboard.h"
// not all keys are mapped in the DigiKeyboard.h file.
// you have to map it here
#define KEY_HOME   0x4A
#define KEY_PAGE_UP   0x4B
#define KEY_PAGE_DOWN   0x4E
#define KEY_ESCAPE   0x29
#define KEY_UP_ARROW   0x52
#define KEY_DOWN_ARROW   0x51
#define KEY_LEFT_ARROW   0x50
#define KEY_RIGHT_ARROW   0x4F

int irPin = 2; //Sensor pin connect to digital pin2 (ATINY85 pin7)
int start_bit = 2200; //Start bit threshold (Microseconds)
int bin_1 = 1000; //Binary 1 threshold (Microseconds)
int bin_0 = 400; //Binary 0 threshold (Microseconds)
const byte BIT_PER_BLOCK = 32;

void setup() {
pinMode(irPin, INPUT);
}

void loop() {
DigiKeyboard.update(); // keep updating the keyboard
// this is generally not necessary but with some older systems it seems to
// prevent missing the first character after a delay:
DigiKeyboard.sendKeyStroke(0);

int key = getIRKey();      //Fetch the key

if(key != 0) //Ignore keys that are zero
{
    //DigiKeyboard.print("=>");//uncomment this if you want to
    //DigiKeyboard.println(key); //print out the value of the button

    switch(key)
    {
      case 78: DigiKeyboard.println("1"); break;
      case 74: DigiKeyboard.println("2"); break;
      case 70: DigiKeyboard.println("3"); break;
      case 77: DigiKeyboard.println("4"); break;
      case 73: DigiKeyboard.println("5"); break;
      case 69: DigiKeyboard.println("6"); break;
      case 76: DigiKeyboard.println("7"); break;
      case 72: DigiKeyboard.println("8"); break;
      case 68: DigiKeyboard.println("9"); break;   
      case 12: DigiKeyboard.println("0"); break;
      case 15: DigiKeyboard.sendKeyStroke(KEY_SPACE); break;
      case6: DigiKeyboard.sendKeyStroke(KEY_ENTER); break;   
      case4: DigiKeyboard.sendKeyStroke(KEY_ESCAPE); break;
      case 81: DigiKeyboard.sendKeyStroke(KEY_HOME); break;
      case 14: DigiKeyboard.sendKeyStroke(KEY_LEFT_ARROW); break;
      case 10: DigiKeyboard.sendKeyStroke(KEY_RIGHT_ARROW); break;
      case 11: DigiKeyboard.sendKeyStroke(KEY_DOWN_ARROW); break;
      case7: DigiKeyboard.sendKeyStroke(KEY_UP_ARROW); break;   
    }   
}
}

/////////////////////////////////////////////////////////////
// decode infrared signal
/////////////////////////////////////////////////////////////
int getIRKey() {
int data;
int i;
while(pulseIn(irPin, HIGH) < start_bit); //Wait for a start bit

for(i = 0 ; i < BIT_PER_BLOCK ; i++)
    data = pulseIn(irPin, HIGH); //Start measuring bits, I only want HIGH pulses

delay(100);
for(i = 0 ; i < BIT_PER_BLOCK ; i++) //Parse them
{   
    if(data > bin_1) //is it a 1?
      data = 1;
    else if(data > bin_0) //is it a 0?
      data = 0;
    else
      return -1; //Flag the data as invalid; Return -1 on invalid data
}

//based on NEC protocol, command data started from bit 16
//and end with bit 24 (8 bits long)
int result = 0;
for(i = 16 ; i < 24; i++) {
    //DigiKeyboard.print(data); //print out the value of button in binary form
    if(data == 1) result |= (1<<i-16); convert="" data="" bits="" to="" integer
}
return result; //Return key number
}


最後一个是4路红外遥控
使用相同的红外遥控器来控制4个LED，按下各自按键将会切换各自相关LED。完成代码(Sketch)上载后 ，你可以除去1.5K电阻，两个68ohm电阻和两个Zener二极管。
此代码占用了1682Byte Flash Memory，可以使用的Flash Memory剩下4330 Byte

int irPin = 2;   //Sensor pin connect to digital pin2 (ATINY85 pin7)
int led1 = 0; //led connect to digital pin0 (ATTINY85 pin5)
int led2 = 1; //led connect to digital pin1 (ATTINY85 pin6)
int led3 = 3; //led connect to digital pin3 (ATTINY85 pin2)
int led4 = 4; //led connect to digital pin4 (ATTINY85 pin3)
int start_bit = 2200; //Start bit threshold (Microseconds)
int bin_1 = 1000; //Binary 1 threshold (Microseconds)
int bin_0 = 400; //Binary 0 threshold (Microseconds)
const byte BIT_PER_BLOCK = 32;

void setup() {
pinMode(irPin, INPUT);
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
digitalWrite(led1, LOW); //turn off LED
digitalWrite(led2, LOW);
digitalWrite(led3, LOW);
digitalWrite(led4, LOW);
}

void loop() {
int key = getIRKey();      //Fetch the key

if(key != 0) //Ignore keys that are zero
{
    switch(key)
    {
      case78: toggleLED(led1); break;
      case74: toggleLED(led2); break;
      case70: toggleLED(led3); break;
      case77: toggleLED(led4); break;
    }   
}
}

/////////////////////////////////////////////////////////////
// toggle led
/////////////////////////////////////////////////////////////
void toggleLED(byte ledPin) {
if(digitalRead(ledPin) != 1) //This toggles the led
    digitalWrite(ledPin, HIGH);
else
    digitalWrite(ledPin, LOW);   
}
/////////////////////////////////////////////////////////////
// decode infrared signal
/////////////////////////////////////////////////////////////
int getIRKey() {
int data;
int i;
while(pulseIn(irPin, HIGH) < start_bit); //Wait for a start bit

for(i = 0 ; i < BIT_PER_BLOCK ; i++)
    data = pulseIn(irPin, HIGH); //Start measuring bits, I only want HIGH pulses

delay(100);
for(i = 0 ; i < BIT_PER_BLOCK ; i++) //Parse them
{   
    if(data > bin_1) //is it a 1?
      data = 1;
    else if(data > bin_0) //is it a 0?
      data = 0;
    else
      return -1; //Flag the data as invalid;Return -1 on invalid data
}

//based on NEC protocol, command data started from bit 16
//and end with bit 24 (8 bits long)
int result = 0;
for(i = 16 ; i < 24; i++) {
    if(data == 1) result |= (1<<i-16); convert="" data="" bits="" to="" integer
}
return result; //Return key number
}

注：
如果你是根据我的方式自制Digispark，由于使用了以下熔丝位，只能拥有五个IO，重置(Reset)不能当着IO。

[*]Extended: 0xFE
[*]High: 0xDD
[*]Low: 0xE1

建议重置(Reset)引脚与Vcc(+5V)之间连接一个1K至10K的电阻器以防止电平漂动。而造成电路不稳定。

smfox10 发表于 2013-6-1 21:00:01

最近玩了下Digispark，挺强大的，我觉得连着电脑特别好玩，带USB，不用串口，谢谢你的分享

smching 发表于 2013-6-2 00:09:32

smfox10 发表于 2013-6-1 21:00 static/image/common/back.gif
最近玩了下Digispark，挺强大的，我觉得连着电脑特别好玩，带USB，不用串口，谢谢你的分享

之前喜欢玩这个最简单又最便宜的Arduino，基本上已经放弃了。现在玩Digispark。
来吧！一起研究Digispark吧。

查看完整版本: Digispark红外接收器