在51hei论坛吸取各位前辈的经验,将之前二极管用量多的问题优化一下,目前不用二极管能接6键,2只二极管能接12键,6只二极管能接18键,9只二极管能接21键,第22键要单独占用3只二极管最不化算。
实验用89S51作试验,电路接线就是P1.2,P1.3,P1.4接键盘,P1.0接显示器。
- /*==================================================================*
- * 3个IO接识别22键测试程序 *
- * ------------------------------------------------ *
- * MCU: AT89C2051 *
- * OSC: 12M cysytel *
- * 程序设计:Cowboy *
- * 程序版本:V1.0 *
- *==================================================================*/
- #include<reg52.h>
- //================== IO口线连接 ==================
- sbit Bus = P1^0;
- sbit IO_a = P1^4;
- sbit IO_b = P1^3;
- sbit IO_c = P1^2;
- //================== 变量声明 ====================
- unsigned char Disp_buf[3];
- unsigned char Dig;
- unsigned char Key_count;
- unsigned char bdata Key_state;
- sbit KB0 = Key_state^0;
- sbit KB1 = Key_state^1;
- sbit KB2 = Key_state^2;
- sbit KB3 = Key_state^3;
- sbit KB4 = Key_state^4;
- sbit KB5 = Key_state^5;
- //================== 表格数据 ====================
- code unsigned char LED_font[24]=
- {
- 0x84,0x9f,0xa2,0x8a,0x99,0xc8,0xc0,0x9e,0x80, //012345678
- 0x88,0x90,0xc1,0xe4,0x83,0xe0,0xf0,0xff,0xfb, //9abcdef -
- };
- code unsigned char Key_tab[64]= //键码映射表
- {// 0 1 2 3 4 5 6 7 8 9
- 22, 0, 2, 0, 0, 0, 0, 0, 4, 0, //0
- 0, 0, 0, 0, 0,18, 0, 0, 0, 0, //1X
- 0, 0, 0, 0, 0, 0, 3,14, 0, 0, //2X
- 20,10, 6, 0, 0, 0, 0, 0, 1,19, //3X
- 0, 5, 0, 0, 0,15, 0,11, 0, 0, //4X
- 0,17, 0, 0,13, 8, 0,21, 0, 9, //5X
- 16,12, 7, 0 //6X
- };
- //=============== 检测按键 =================
- void Key_scan()
- {
- unsigned char i;
- Key_count --; //扫描次序
- Key_count &= 3;
- switch (Key_count) //按次序处理
- {
- case 2: //第一轮扫描
- KB0 = IO_b;
- KB1 = IO_c;
- IO_a = 1;
- IO_b = 0;
- break;
- case 1: //每二轮扫描
- KB2 = IO_c;
- KB3 = IO_a;
- IO_b = 1;
- IO_c = 0;
- break;
- case 0: //每三轮扫描
- KB4 = IO_a;
- KB5 = IO_b;
- IO_c = 1;
- break;
- default: //每四轮扫描
- if (!IO_a) KB0 = 0;
- if (!IO_b) KB2 = 0;
- if (!IO_c) KB4 = 0;
- IO_a = 0;
- //======更新显示缓冲区=======
- i = Key_tab[Key_state];
- if (i == 0)
- {
- Disp_buf[2] = 0x11; //显示三横
- Disp_buf[1] = 0x11;
- Disp_buf[0] = 0x11;
- }
- else
- {
- Disp_buf[2] = 0x0c; //字符"C"
- Disp_buf[1] = i / 10; //键码十位
- Disp_buf[0] = B;于 //键码个位
- }
- Key_state = 0;
- }
- }
- /*===================================================================
- ONE WIRE 显示总线驱动程序
- ===================================================================*/
- //=============== 发送一位 =================
- void Send_bit(bit Dat)
- {
- unsigned char i = 3;
- if (!Dat) Bus = 0;
- else
- {
- Bus = 0;
- Bus = 1;
- }
- while(--i); //延时8us
- Bus = 1;
- }
- //=============== 总线驱动 =================
- void Bus_drive()
- {
- unsigned char i = 0;
- unsigned char Sdat;
- Send_bit(1); //Bit6消隐
- do Bus = 1; while(--i); //延时768us
- do Bus = 0; while(--i); //延时768us
- Bus = 1;
- Sdat = LED_font[Disp_buf[Dig++]]; //获取显示数据
- Send_bit(Sdat & 0x01); //发送位0
- Send_bit(Sdat & 0x02); //发送位1
- Send_bit(Sdat & 0x04); //发送位2
- Send_bit(Sdat & 0x08); //发送位3
- Send_bit(Sdat & 0x10); //发送位4
- Send_bit(Sdat & 0x20); //发送位5
- Send_bit(Dig & 0x01); //发送位选1
- Send_bit(Dig & 0x02); //发送位选2
- while(--i); //延时512us
- Send_bit(Sdat & 0x40); //发送位6
- for (i = 7;i> 0;i--) Send_bit(1); //位6移至Dout
- if (Dig == 3) Dig = 0;
- }
- /*===================================================================
- 延时 5ms 程序
- ===================================================================*/
- void Delay_5ms()
- {
- while(!TF1);
- TF1 = 0;
- TH1 = (- 5000) / 256;
- TL1 = (- 5000) % 256;
- }
- /*===================================================================
- 主程序
- ===================================================================*/
- void main()
- {
- TMOD = 0x10; //定时器1,16位模式
- TCON = 0xc0; //TR1=1;TF1=1;
- while(1) //主循环
- {
- Bus_drive(); //显示总线驱动
- Key_scan(); //检测按键
- Delay_5ms(); //延时5MS
- }
- }
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