# Arduino读取键盘[转载]

- URL: https://wuming.si/blog/1047/
- Author: Aaron
- Published: 2015-11-09
- Language: zh-Hans
- Categories: Technology
- Originally published at: https://blog.wo.ai/archives/1047

## Arduino读取键盘

[![Arduino_and_Keypad](https://wuming.si/images/2015/11/Arduino_and_Keypad-300x78.jpg)](https://wuming.si/images/2015/11/Arduino_and_Keypad.jpg)

这里提供两种方式从Arduino读取键盘。第一种方式是使用矩阵式（Matrix）键盘，另一种方式是使用PS2键盘。

**矩阵键盘（Matrix keypad）**  
首先必须安装Arduino Keypad键盘库（Keypad library），Arduino Keypad键盘库可以从[Arduino Playground](http://playground.arduino.cc//Code/Keypad)下载。Arduino Keypad键盘库让你读取矩阵式键盘而不用编写复杂的代码，此键盘库可以读取3×4， 4×4以及各种矩阵结构的键盘。

**使用Arduino Keypad键盘库注意事项**

  * 该键盘库是属于无阻塞式，按下谋键不放，其余（接下来）的代码还是会继续运行
  * 如果编写控制键盘处运用到delay()，这将造成键盘反应迟顿
  * 按下谋键，getKey()只返回一个键值，而不是自动重复。松开按键时，可以追踪其RELEASED event

**安装Arduino Keypad键盘库**

  * [下载](http://playground.arduino.cc/uploads/Code/keypad.zip)Arduino Keypad键盘库
  * 将下载了的文件（keypad.zip）解压至Arduino软件的libraries文件夹，如图

[![Arduino_keypad_library](https://wuming.si/images/2015/11/Arduino_keypad_library-300x122.jpg)](https://wuming.si/images/2015/11/Arduino_keypad_library.jpg)

  * 打开Arduino软件
  * 选择File>Examples>Keypad，将会看见以下画面，表示Arduino Keypad键盘库安装成功

[![Arduino_keypad_examples](https://wuming.si/images/2015/11/Arduino_keypad_examples-246x300.jpg)](https://wuming.si/images/2015/11/Arduino_keypad_examples.jpg)

**4×4矩阵keypad示范**  
根据下面接线连接键盘至Arduino

[![4x4_matrix_membrane_keypad_pinout](https://wuming.si/images/2015/11/4x4_matrix_membrane_keypad_pinout-300x147.jpg)](https://wuming.si/images/2015/11/4x4_matrix_membrane_keypad_pinout.jpg)

**Arduino** |  **4×4 Keypad**  
---|---  
D2 |  1  
D3 |  2  
D4 |  3  
D5 |  4  
D6 |  5  
D7 |  6  
D8 |  7  
D9 |  8  
  
上载以下代码至Arduino

#include <Keypad.h> const byte ROWS = 4; // Four rows  
const byte COLS = 4; // Four columns //Define the keymap  
char keys[ROWS][COLS] = {  
{‘1′,’2′,’3′,’A’},  
{‘4′,’5′,’6′,’B’},  
{‘7′,’8′,’9′,’C’},  
{‘*’,’0′,’#’,’D’}  
}; //// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.  
byte rowPins[ROWS] = {6,7,8,9}; // Connect keypad COL0, COL1, COL2 and COL3 to these Arduino pins.  
byte colPins[COLS] = {2,3,4,5}; //connect to column pinouts // Create the Keypad  
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS ); void setup(){  
Serial.begin(9600);  
} void loop(){  
char key = keypad.getKey(); if (key != NO_KEY){  
Serial.println(key);  
}  
}  
---  
  
使用Arduino软件自带的串口监视器（Serial Monitor）来测试此程序（Baud rate必须设成9600）。当按下谋键时，其返回值将显示在串口监视器。

* * *

**PS2键盘**

首先必须安装Arduino PS2键盘库（PS2keyboard library)，Arduino PS2键盘库可以从[这里下载](http://www.pjrc.com/teensy/td_libs_PS2Keyboard.html)。

**安装Arduino PS2键盘库**

  * [下载](http://www.pjrc.com/teensy/arduino_libraries/PS2Keyboard.zip)Arduino PS2键盘库
  * 将下载了的文件（PS2keyboard.zip）解压至Arduino软件的libraries文件夹
  * 安装方法与安装keypad相似，请参考之。

********

****PS2键盘** 示范**  
根据下面接线连接键盘至Arduino

[![PS2_keyboarad_pinout](https://wuming.si/images/2015/11/PS2_keyboarad_pinout-300x74.jpg)](https://wuming.si/images/2015/11/PS2_keyboarad_pinout.jpg)

**Keyboard** |  **Arduino**  
---|---  
4 (+5V) |  5V  
3 (GND) | GND  
5 (Clock) |  Digital Pin 3  
1 (Datak) |  Digital Pin 4  
  
上载以下代码至Arduino

#include <PS2Keyboard.h> const int DataPin = 8;  
const int IRQpin = 5; PS2Keyboard keyboard; void setup() {  
delay(1000);  
keyboard.begin(DataPin, IRQpin);  
Serial.begin(9600);  
Serial.println(“Keyboard Test:”);  
} void loop() {  
if (keyboard.available()) { char c = keyboard.read(); // read the next key // check for some of the special keys  
if (c == PS2_ENTER) {  
Serial.println();  
} else if (c == PS2_TAB) {  
Serial.print(“[Tab]”);  
} else if (c == PS2_ESC) {  
Serial.print(“[ESC]”);  
} else if (c == PS2_PAGEDOWN) {  
Serial.print(“[PgDn]”);  
} else if (c == PS2_PAGEUP) {  
Serial.print(“[PgUp]”);  
} else if (c == PS2_LEFTARROW) {  
Serial.print(“[Left]”);  
} else if (c == PS2_RIGHTARROW) {  
Serial.print(“[Right]”);  
} else if (c == PS2_UPARROW) {  
Serial.print(“[Up]”);  
} else if (c == PS2_DOWNARROW) {  
Serial.print(“[Down]”);  
} else if (c == PS2_DELETE) {  
Serial.print(“[Del]”);  
} else {  
Serial.print(c); // otherwise, just print all normal characters  
}  
}  
}  
---  
  
使用Arduino软件自带的串口监视器（Serial Monitor）来测试此程序（Baud rate必须设成9600）。当按下谋键时，其返回值将显示在串口监视器。

* * *

**增加按键音效**  
按照下面图象连接PC扬声器（此PC扬声器可以从废棄的电脑主板拆岀来），然後稍微更改代码。由于没有此PC扬声器的规格说明，估计供电5V且功率非常小，能够直接由Arduino驱动。如果不放心，可以在Aruino pin10与扬声器之间添加一个100欧姆电阻器。

[![Connecting_PC_speaker_to_Arduino](https://wuming.si/images/2015/11/Connecting_PC_speaker_to_Arduino-300x222.jpg)](https://wuming.si/images/2015/11/Connecting_PC_speaker_to_Arduino.jpg)

代码方面使用了tone()函数，具体可以浏览Arduino Reference网站  
<http://arduino.cc/en/Reference/Tone>

tone()用法

  * tone(pin, frequency)
  * tone(pin, frequency, duration)

  1. pin是连接扬声器的引脚
  2. frequency是输出频率，频率越低，音频就越低。
  3. duration音频输出持续时间

  1. #include <Keypad.h>

  2. const byte ROWS = 4; // Four rows

  3. const byte COLS = 4; // Four columns

  4.   5. //Define the keymap

  6. char keys[ROWS][COLS] = {

  7. {‘1′,’2′,’3′,’A’},

  8. {‘4′,’5′,’6′,’B’},

  9. {‘7′,’8′,’9′,’C’},

  10. {‘*’,’0′,’#’,’D’}

  11. };

  12.   13. //// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.

  14. byte rowPins[ROWS] = {6,7,8,9};

  15.   16. // Connect keypad COL0, COL1, COL2 and COL3 to these Arduino pins.

  17. byte colPins[COLS] = {2,3,4,5}; //connect to column pinouts

  18.   19. // Create the Keypad

  20. Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

  21.   22. void setup(){

  23. Serial.begin(9600);

  24. }

  25.   26. void loop(){

  27. char key = keypad.getKey();

  28. if (key != NO_KEY){

  29. delay(50); //act as debounce

  30. beep();

  31. Serial.println(key);

  32. }

  33. }

  34.   35. #define SPEAKER_PIN 10

  36. void beep(){

  37. tone(SPEAKER_PIN,2000,90);

  38. delay(20);

  39. noTone(SPEAKER_PIN);

  40. }

转自

http://ediy.com.my/index.php/2012-10-21-15-15-03/2013-04-14-05-06-50/item/65-arduino%E8%AF%BB%E5%8F%96%E9%94%AE%E7%9B%98