Digispark红外接收器

西门庆33

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。

1. int irPin=2;  //digital 2 (ATTINT85 pin 7)
   
2. int ledPin=0; //digital 0 (ATTINY85 pin 5)
   
3. 
   
4. void setup()
   
5. {
   
6. pinMode(irPin,INPUT);
   
7. pinMode(ledPin,OUTPUT);
   
8. digitalWrite(0,HIGH);
   
9. }
   
10. 
    
11. void loop()
    
12. {
    
13.   if(pulseIn(irPin,LOW)) //reads a pulse on a pin
    
14.   {
    
15.      //button pressed
    
16.      delay(100);
    
17.      digitalWrite(ledPin,HIGH);
    
18.      delay(1000);
    
19.      digitalWrite(ledPin,LOW);
    
20.   }  
    
21. }

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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。

1. int irPin = 2; //IR detector connected to digital 2
   
2. const byte BIT_PER_BLOCK = 32;
   
3. 
   
4. void setup() {
   
5.   pinMode(irPin, INPUT);
   
6.   Serial.begin(9600);
   
7. }
   
8. void loop() {
   
9.   int data[BIT_PER_BLOCK];
   
10.   int i;  
    
11. 
    
12.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    
13.     //Start measuring bits, I only want high pulses
    
14.     //you may want to use LOW pulse --> pulseIn(irPin, LOW)
    
15.     data[i] = pulseIn(irPin, HIGH);   
    
16.   }
    
17. 
    
18.   delay(100);
    
19.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    
20.     Serial.println(data[i]);
    
21.   }  
    
22.   Serial.println("=========");
    
23. }

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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。

1. #include "DigiKeyboard.h"
   
2. int irPin = 2; //IR receiver wired to digital 2 (ATTINY pin7)
   
3. const byte BIT_PER_BLOCK = 32;
   
4. void setup() {
   
5.   pinMode(irPin, INPUT);
   
6.   Serial.begin(9600);
   
7. }
   
8. void loop() {
   
9.   int data[BIT_PER_BLOCK];
   
10.   int i;  
    
11. 
    
12.   // this is generally not necessary but with some older systems it seems to
    
13.   // prevent missing the first character after a delay:
    
14.   DigiKeyboard.sendKeyStroke(0);  
    
15. 
    
16.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    
17.     //Start measuring bits, I only want high pulses
    
18.     //you may want to use LOW pulse --> pulseIn(irPin, LOW)
    
19.     data[i] = pulseIn(irPin, HIGH);
    
20.   }
    
21. 
    
22.   delay(100);
    
23.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) {
    
24.     DigiKeyboard.println(data[i]);
    
25.   }  
    
26.   DigiKeyboard.println("=========");
    
27. }

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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。

1. #include "DigiKeyboard.h"
   
2. int irPin = 2; //Sensor pin connect to digital pin2 (ATINY85 pin7)
   
3. int start_bit = 2200; //Start bit threshold (Microseconds)
   
4. int bin_1 = 1000; //Binary 1 threshold (Microseconds)
   
5. int bin_0 = 400; //Binary 0 threshold (Microseconds)
   
6. const byte BIT_PER_BLOCK = 32;
   
7. 
   
8. void setup() {
   
9.   pinMode(irPin, INPUT);
   
10. }
    
11. 
    
12. void loop() {
    
13.   DigiKeyboard.update(); //keep on updating the keyboard
    
14.   // this is generally not necessary but with some older systems it seems to
    
15.   // prevent missing the first character after a delay:
    
16.   DigiKeyboard.sendKeyStroke(0);
    
17. 
    
18.   int key = getIRKey();        //Fetch the key
    
19. 
    
20.   if(key != 0) //Ignore keys that are zero
    
21.   {
    
22.     DigiKeyboard.print("=>");  //uncomment this if you want to
    
23.     DigiKeyboard.println(key); //print out the value of the button
    
24.   }
    
25. }
    
26. 
    
27. /////////////////////////////////////////////////////////////
    
28. // decode infrared signal
    
29. /////////////////////////////////////////////////////////////
    
30. int getIRKey() {
    
31.   int data[BIT_PER_BLOCK];
    
32.   int i;
    
33.   while(pulseIn(irPin, HIGH) < start_bit); //Wait for a start bit
    
34. 
    
35.   for(i = 0 ; i < BIT_PER_BLOCK ; i++)
    
36.     data[i] = pulseIn(irPin, HIGH); //Start measuring bits, I only want HIGH pulses
    
37. 
    
38.   delay(100);  
    
39.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) //Parse them
    
40.   {   
    
41.     if(data[i] > bin_1) //is it a 1?
    
42.       data[i] = 1;
    
43.     else if(data[i] > bin_0) //is it a 0?
    
44.       data[i] = 0;
    
45.     else
    
46.       return -1; //Flag the data as invalid;  Return -1 on invalid data
    
47.   }
    
48.   //based on NEC protocol, command data started from bit 16
    
49.   //and end with bit 24 (8 bits long)
    
50.   int result = 0;
    
51.   for(i = 16 ; i < 24; i++) {
    
52.     DigiKeyboard.print(data[i]); //print out the value of button in binary form
    
53.     if(data[i] == 1) result |= (1<<i-16); //Convert data bits to integer
    
54.   }  
    
55.   return result; //Return key number
    
56. }

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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 。

1. #include "DigiKeyboard.h"
   
2. // not all keys are mapped in the DigiKeyboard.h file.
   
3. // you have to map it here
   
4. #define KEY_HOME   0x4A
   
5. #define KEY_PAGE_UP   0x4B
   
6. #define KEY_PAGE_DOWN   0x4E
   
7. #define KEY_ESCAPE   0x29
   
8. #define KEY_UP_ARROW   0x52
   
9. #define KEY_DOWN_ARROW   0x51
   
10. #define KEY_LEFT_ARROW   0x50
    
11. #define KEY_RIGHT_ARROW   0x4F
    
12. 
    
13. int irPin = 2; //Sensor pin connect to digital pin2 (ATINY85 pin7)
    
14. int start_bit = 2200; //Start bit threshold (Microseconds)
    
15. int bin_1 = 1000; //Binary 1 threshold (Microseconds)
    
16. int bin_0 = 400; //Binary 0 threshold (Microseconds)
    
17. const byte BIT_PER_BLOCK = 32;
    
18. 
    
19. void setup() {
    
20.   pinMode(irPin, INPUT);
    
21. }
    
22. 
    
23. void loop() {
    
24.   DigiKeyboard.update(); // keep updating the keyboard
    
25.   // this is generally not necessary but with some older systems it seems to
    
26.   // prevent missing the first character after a delay:
    
27.   DigiKeyboard.sendKeyStroke(0);
    
28. 
    
29.   int key = getIRKey();        //Fetch the key
    
30. 
    
31.   if(key != 0) //Ignore keys that are zero
    
32.   {
    
33.     //DigiKeyboard.print("=>");  //uncomment this if you want to
    
34.     //DigiKeyboard.println(key); //print out the value of the button
    
35. 
    
36.     switch(key)
    
37.     {
    
38.       case 78: DigiKeyboard.println("1"); break;
    
39.       case 74: DigiKeyboard.println("2"); break;
    
40.       case 70: DigiKeyboard.println("3"); break;
    
41.       case 77: DigiKeyboard.println("4"); break;
    
42.       case 73: DigiKeyboard.println("5"); break;
    
43.       case 69: DigiKeyboard.println("6"); break;
    
44.       case 76: DigiKeyboard.println("7"); break;
    
45.       case 72: DigiKeyboard.println("8"); break;
    
46.       case 68: DigiKeyboard.println("9"); break;   
    
47.       case 12: DigiKeyboard.println("0"); break;
    
48.       case 15: DigiKeyboard.sendKeyStroke(KEY_SPACE); break;
    
49.       case  6: DigiKeyboard.sendKeyStroke(KEY_ENTER); break;   
    
50.       case  4: DigiKeyboard.sendKeyStroke(KEY_ESCAPE); break;
    
51.       case 81: DigiKeyboard.sendKeyStroke(KEY_HOME); break;
    
52.       case 14: DigiKeyboard.sendKeyStroke(KEY_LEFT_ARROW); break;
    
53.       case 10: DigiKeyboard.sendKeyStroke(KEY_RIGHT_ARROW); break;
    
54.       case 11: DigiKeyboard.sendKeyStroke(KEY_DOWN_ARROW); break;  
    
55.       case  7: DigiKeyboard.sendKeyStroke(KEY_UP_ARROW); break;   
    
56.     }   
    
57.   }
    
58. }
    
59. 
    
60. /////////////////////////////////////////////////////////////
    
61. // decode infrared signal
    
62. /////////////////////////////////////////////////////////////
    
63. int getIRKey() {
    
64.   int data[BIT_PER_BLOCK];
    
65.   int i;
    
66.   while(pulseIn(irPin, HIGH) < start_bit); //Wait for a start bit
    
67. 
    
68.   for(i = 0 ; i < BIT_PER_BLOCK ; i++)
    
69.     data[i] = pulseIn(irPin, HIGH); //Start measuring bits, I only want HIGH pulses
    
70. 
    
71.   delay(100);  
    
72.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) //Parse them
    
73.   {   
    
74.     if(data[i] > bin_1) //is it a 1?
    
75.       data[i] = 1;
    
76.     else if(data[i] > bin_0) //is it a 0?
    
77.       data[i] = 0;
    
78.     else
    
79.       return -1; //Flag the data as invalid;  Return -1 on invalid data
    
80.   }
    
81. 
    
82.   //based on NEC protocol, command data started from bit 16
    
83.   //and end with bit 24 (8 bits long)
    
84.   int result = 0;
    
85.   for(i = 16 ; i < 24; i++) {
    
86.     //DigiKeyboard.print(data[i]); //print out the value of button in binary form
    
87.     if(data[i] == 1) result |= (1<<i-16); //Convert data bits to integer
    
88.   }  
    
89.   return result; //Return key number
    
90. }

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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。
有句广东话：打完齊唔要和尚
此代码占用了1682Byte Flash Memory，可以使用的Flash Memory剩下4330 Byte 。

1. int irPin = 2;   //Sensor pin connect to digital pin2 (ATINY85 pin7)
   
2. int led1 = 0; //led connect to digital pin0 (ATTINY85 pin5)
   
3. int led2 = 1; //led connect to digital pin1 (ATTINY85 pin6)
   
4. int led3 = 3; //led connect to digital pin3 (ATTINY85 pin2)
   
5. int led4 = 4; //led connect to digital pin4 (ATTINY85 pin3)
   
6. int start_bit = 2200; //Start bit threshold (Microseconds)
   
7. int bin_1 = 1000; //Binary 1 threshold (Microseconds)
   
8. int bin_0 = 400; //Binary 0 threshold (Microseconds)
   
9. const byte BIT_PER_BLOCK = 32;
   
10. 
    
11. void setup() {
    
12.   pinMode(irPin, INPUT);
    
13.   pinMode(led1, OUTPUT);
    
14.   pinMode(led2, OUTPUT);
    
15.   pinMode(led3, OUTPUT);
    
16.   pinMode(led4, OUTPUT);
    
17.   digitalWrite(led1, LOW); //turn off LED
    
18.   digitalWrite(led2, LOW);
    
19.   digitalWrite(led3, LOW);
    
20.   digitalWrite(led4, LOW);
    
21. }
    
22. 
    
23. void loop() {
    
24.   int key = getIRKey();        //Fetch the key
    
25. 
    
26.   if(key != 0) //Ignore keys that are zero
    
27.   {
    
28.     switch(key)
    
29.     {
    
30.       case  78: toggleLED(led1); break;
    
31.       case  74: toggleLED(led2); break;
    
32.       case  70: toggleLED(led3); break;
    
33.       case  77: toggleLED(led4); break;
    
34.     }   
    
35.   }
    
36. }
    
37. 
    
38. /////////////////////////////////////////////////////////////
    
39. // toggle led
    
40. /////////////////////////////////////////////////////////////
    
41. void toggleLED(byte ledPin) {
    
42.   if(digitalRead(ledPin) != 1) //This toggles the led
    
43.     digitalWrite(ledPin, HIGH);
    
44.   else
    
45.     digitalWrite(ledPin, LOW);   
    
46. }
    
47. /////////////////////////////////////////////////////////////
    
48. // decode infrared signal
    
49. /////////////////////////////////////////////////////////////
    
50. int getIRKey() {
    
51.   int data[BIT_PER_BLOCK];
    
52.   int i;
    
53.   while(pulseIn(irPin, HIGH) < start_bit); //Wait for a start bit
    
54. 
    
55.   for(i = 0 ; i < BIT_PER_BLOCK ; i++)
    
56.     data[i] = pulseIn(irPin, HIGH); //Start measuring bits, I only want HIGH pulses
    
57. 
    
58.   delay(100);  
    
59.   for(i = 0 ; i < BIT_PER_BLOCK ; i++) //Parse them
    
60.   {   
    
61.     if(data[i] > bin_1) //is it a 1?
    
62.       data[i] = 1;
    
63.     else if(data[i] > bin_0) //is it a 0?
    
64.       data[i] = 0;
    
65.     else
    
66.       return -1; //Flag the data as invalid;  Return -1 on invalid data
    
67.   }
    
68. 
    
69.   //based on NEC protocol, command data started from bit 16
    
70.   //and end with bit 24 (8 bits long)
    
71.   int result = 0;
    
72.   for(i = 16 ; i < 24; i++) {
    
73.     if(data[i] == 1) result |= (1<<i-16); //Convert data bits to integer
    
74.   }  
    
75.   return result; //Return key number
    
76. }

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