一、LCD调试工具函数：

使用：

所有函数，前两个参数，均为指定显示位置。

四个参数的，第四个参数，为保留位数，少的保留后面（123,2 -> 23），多的前面补零。

二、矩阵键盘：

1、矩阵键盘的原理：

通过行和列来具体检测每个按键的情况：

如电脑分辨率1920*1080个LED，只需1920+1080个接口即可控制。

在单片机中，16个按键只需8个接口（4行+4列）。

使用方法：依次给行赋值 0111,1011,1101,1110，每次赋值后检测列的状态，列为0说明接通了。

2. 矩阵键盘判断函数封装：

/*
用途：读取矩阵键盘按键键码、
使用：按下按键，停留在此函数，松手返回键码，没按下返回0。
*/
unsigned char MatrixKey()
{unsigned char KeyNumber = 0;//第一列P1 = 0xFF;P1_3 = 0;if (P1_7 == 0) { Delay(20); while (P1_7 == 0); Delay(20); KeyNumber = 1; }if (P1_6 == 0) { Delay(20); while (P1_6 == 0); Delay(20); KeyNumber = 5; }if (P1_5 == 0) { Delay(20); while (P1_5 == 0); Delay(20); KeyNumber = 9; }if (P1_4 == 0) { Delay(20); while (P1_4 == 0); Delay(20); KeyNumber = 13; }//第二列P1 = 0xFF;P1_2 = 0;if (P1_7 == 0) { Delay(20); while (P1_7 == 0); Delay(20); KeyNumber = 2; }if (P1_6 == 0) { Delay(20); while (P1_6 == 0); Delay(20); KeyNumber = 6; }if (P1_5 == 0) { Delay(20); while (P1_5 == 0); Delay(20); KeyNumber = 10; }if (P1_4 == 0) { Delay(20); while (P1_4 == 0); Delay(20); KeyNumber = 14; }//第三列P1 = 0xFF;P1_1 = 0;if (P1_7 == 0) { Delay(20); while (P1_7 == 0); Delay(20); KeyNumber = 3; }if (P1_6 == 0) { Delay(20); while (P1_6 == 0); Delay(20); KeyNumber = 7; }if (P1_5 == 0) { Delay(20); while (P1_5 == 0); Delay(20); KeyNumber = 11; }if (P1_4 == 0) { Delay(20); while (P1_4 == 0); Delay(20); KeyNumber = 15; }//第四列P1 = 0xFF;P1_0 = 0;if (P1_7 == 0) { Delay(20); while (P1_7 == 0); Delay(20); KeyNumber = 4; }if (P1_6 == 0) { Delay(20); while (P1_6 == 0); Delay(20); KeyNumber = 8; }if (P1_5 == 0) { Delay(20); while (P1_5 == 0); Delay(20); KeyNumber = 12; }if (P1_4 == 0) { Delay(20); while (P1_4 == 0); Delay(20); KeyNumber = 16; }
}

3.实战：显示按键编号

void main()
{LCD_Init();LCD_ShowString(1, 1, "MatrixKey:");while (1){int KeyNum = MatrixKey();if (KeyNum){LCD_ShowNum(2, 1, KeyNum, 2);}}
}

4.实战：密码锁

四位密码锁，1-9号键为对应键码，10为0，11是确认，12是清除。

unsigned char KeyNum = 0;
unsigned int PassWord0 = 4359;//初始密码
unsigned int PassWord = 0;
unsigned int Count = 0;
void main()
{LCD_Init();LCD_ShowString(1, 1, "PassWord:");while (1){KeyNum = MatrixKey();if (KeyNum){if (KeyNum <= 10 && Count < 4)//按1-10输入{PassWord *= 10;PassWord += KeyNum % 10;LCD_ShowNum(2, 1, PassWord, 4);Count++;}else if (KeyNum == 11)//按11确认{if (PassWord == PassWord0){LCD_ShowString(1, 14, "OK ");break;}else{LCD_ShowString(1, 14, "ERR");PassWord = 0;Count = 0;LCD_ShowNum(2, 1, PassWord, 4);}}else if (KeyNum == 12)//按12取消{PassWord = 0;Count = 0;LCD_ShowNum(2, 1, PassWord, 4);}}}
}