Arduino简单实例十三_四位数码管

1)       说明：

数码管是一种半导体发光器件，其基本单元是发光二极管。因此也需要串联电阻，以防电流过大。每个数字由7条线组成，用a-g控制，同时用A1-A4控制当前设置的四个数字中的哪一个。

2)       硬件：

5461AS四位共阴数码管，Arduinouno，220欧电阻四个，线若干

3)       连接：

限流电阻（4个）串联在阴极。A1，A2，A3，A4用于选择显示哪个字符，也是阴极。

4)       代码

#define d_a 2  #define d_b 3  #define d_c 4  #define d_d 5  	#define d_e 6  #define d_f 7  #define d_g 8  #define d_h 9    #define COM1 10  #define COM2 11  #define COM3 12  #define COM4 13    unsigned char num[17][8] = {   //a  b  c  d  e  f  g  h     {1, 1, 1, 1, 1, 1, 0, 0},     //0    {0, 1, 1, 0, 0, 0, 0, 0},     //1    {1, 1, 0, 1, 1, 0, 1, 0},     //2    {1, 1, 1, 1, 0, 0, 1, 0},     //3    {0, 1, 1, 0, 0, 1, 1, 0},     //4    {1, 0, 1, 1, 0, 1, 1, 0},     //5    {1, 0, 1, 1, 1, 1, 1, 0},     //6    {1, 1, 1, 0, 0, 0, 0, 0},     //7    {1, 1, 1, 1, 1, 1, 1, 0},     //8    {1, 1, 1, 1, 0, 1, 1, 0},     //9    {1, 1, 1, 0, 1, 1, 1, 1},     //A    {1, 1, 1, 1, 1, 1, 1, 1},     //B    {1, 0, 0, 1, 1, 1, 0, 1},     //C    {1, 1, 1, 1, 1, 1, 0, 1},     //D    {1, 0, 0, 1, 1, 1, 1, 1},     //E    {1, 0, 0, 0, 1, 1, 1, 1},     //F    {0, 0, 0, 0, 0, 0, 0, 1},     //.  };    void setup()  {      pinMode(d_a,OUTPUT);      pinMode(d_b,OUTPUT);      pinMode(d_c,OUTPUT);      pinMode(d_d,OUTPUT);      pinMode(d_e,OUTPUT);      pinMode(d_f,OUTPUT);      pinMode(d_g,OUTPUT);      pinMode(d_h,OUTPUT);        pinMode(COM1,OUTPUT);      pinMode(COM2,OUTPUT);      pinMode(COM3,OUTPUT);      pinMode(COM4,OUTPUT);  }    void loop()  {   for(int l = 0;l < 10;l++ )    {      for(int k = 0; k < 10;k++)      {        for(int j = 0; j < 10; j++)        {          for(int i = 0;i < 10;i++)          {            //1000/8=125            for(int q = 0;q<125;q++)            {              Display(1,l);             delay(2);              Display(2,k);              delay(2);              Display(3,j);              delay(2);              Display(4,i);              delay(2);            }          }        }      }    }  }    void Display(unsigned char com,unsigned char n) {      digitalWrite(d_a,LOW);      digitalWrite(d_b,LOW);      digitalWrite(d_c,LOW);      digitalWrite(d_d,LOW);      digitalWrite(d_e,LOW);      digitalWrite(d_f,LOW);      digitalWrite(d_g,LOW);      digitalWrite(d_h,LOW);        switch(com) {          case 1:              digitalWrite(COM1,LOW);              digitalWrite(COM2,HIGH);              digitalWrite(COM3,HIGH);              digitalWrite(COM4,HIGH);              break;          case 2:              digitalWrite(COM1,HIGH);              digitalWrite(COM2,LOW);              digitalWrite(COM3,HIGH);              digitalWrite(COM4,HIGH);              break;          case 3:              digitalWrite(COM1,HIGH);              digitalWrite(COM2,HIGH);              digitalWrite(COM3,LOW);              digitalWrite(COM4,HIGH);              break;          case 4:              digitalWrite(COM1,HIGH);              digitalWrite(COM2,HIGH);              digitalWrite(COM3,HIGH);              digitalWrite(COM4,LOW);             break;          default:break;      }      digitalWrite(d_a,num[n][0]);	     digitalWrite(d_b,num[n][1]);      digitalWrite(d_c,num[n][2]);      digitalWrite(d_d,num[n][3]);      digitalWrite(d_e,num[n][4]);      digitalWrite(d_f,num[n][5]);      digitalWrite(d_g,num[n][6]);      digitalWrite(d_h,num[n][7]);  }  
（请注意：因各厂商硬件不同，引脚位置可能有差异,具体请见硬件说明书）