基于CH451的键盘扫描程序设计.doc

基于CH451的键盘扫描程序设计简介：基于CH451的键盘扫描程序设计采用AVR单片机ATmega16进行读取CH451的接收到的按键值，CH451可以实现8*8矩阵键盘输入，且带有中断提醒，接收到的按键值在12864液晶上显示。程序中采用的是2*3矩阵。系统采用AVR Studio+WinAVR构成的AVR GCC编译环境。系统源程序如下：#define F_CPU 1000000UL#include #include #include #include #define nop() asm(NOP)/*液晶显示引脚定义*/*对rs引脚进行定义与设置*/#define rs_out DDRD|=_BV(PD5)#define rs_in DDRD&=_BV(PD5)#define rs_1 PORTD|=_BV(PD5)#define rs_0 PORTD&=_BV(PD5)/*对rw引脚进行定义与设置*/#define rw_out DDRD|=_BV(PD6)#define rw_in DDRD&=_BV(PD6)#define rw_1 PORTD|=_BV(PD6)#define rw_0 PORTD&=_BV(PD6)/*对使能en引脚进行定义与设置*/#define en_out DDRD|=_BV(PD7)#define en_in DDRD&=_BV(PD7)#define en_1 PORTD|=_BV(PD7)#define en_0 PORTD&=_BV(PD7)#define busy_1 DDRB|=_BV(PB7)#define busy_0 DDRB&=_BV(PB7)/*ch451引脚定义*/*数据输出与键盘中断*/#define dout_out DDRA|=_BV(PA2)#define dout_in DDRA&=_BV(PA2)#define dout_1 PORTA|=_BV(PA2)#define dout_0 PORTA&=_BV(PA2)#define dout_read (PINA&_BV(PA2) /*串行数据加载引脚*/#define load_out DDRA|=_BV(PA3)#define load_in DDRA&=_BV(PA3)#define load_1 PORTA|=_BV(PA3)#define load_0 PORTA&=_BV(PA3)/*数据输入引脚*/#define din_out DDRA|=_BV(PA4)#define din_in DDRA&=_BV(PA4)#define din_1 PORTA|=_BV(PA4)#define din_0 PORTA&=_BV(PA4)/*数据时钟线*/#define dclk_out DDRA|=_BV(PA5)#define dclk_in DDRA&=_BV(PA5)#define dclk_1 PORTA|=_BV(PA5)#define dclk_0 PORTA&=_BV(PA5)const unsigned char tabn=0123456789;unsigned char temp=0;/*检查引脚是否忙*/void checkbusy()rs_0;rw_1;en_1;_delay_us(200);busy_0;while(PINB&0x80)=1);en_0;busy_1;/*写命令*/void write_com(unsigned char cmd)checkbusy();rs_0;rw_0;en_1;_delay_us(1);PORTB=cmd;_delay_us(2);en_0;/*写数据*/void write_date(unsigned char dat)checkbusy();rs_1;rw_0;en_1;_delay_us(2);PORTB=dat;_delay_us(2);en_0;/*液晶初始化*/void init_lcd()DDRB=0xff;PORTB=0xff;DDRD=0xff;PORTB=0xff;write_com(0x30);_delay_us(2);write_com(0x0c);_delay_us(2);write_com(0x01);_delay_us(2);write_com(0x06);_delay_us(2);/*向lcd写入一个字符串*/void write_string(const unsigned char *s)while(*s0)write_date(*s);s+;_delay_us(1);_delay_ms(3);/*向lcd某个地址写入一个字符串*/void write_addstr(unsigned char add,const unsigned char *s)write_com(add);while(*s0)write_date(*s);s+;_delay_us(1);/*向ch451写命令*/void write_ch451(unsigned int cmd)unsigned char i;load_0;for(i=0;i1;dclk_1;load_1;/*初始化ch451*/void init_ch451()din_0;din_1;write_ch451(0x0201);/初始化芯片内部write_ch451(0x0402);/开键盘、关显示、关看门狗write_ch451(0x0508);/BCD译码write_ch451(0x0600);/不闪烁/*读取ch451的按键值*/unsigned char read_ch451() unsigned char i,date=0; din_1; /输入下拉load_1; dclk_1;for(i=0;i4;i+)dclk_0;if(i=3)din_0;dclk_1;load_0;load_1;for(i=0;i7;i+)date=1;if(dout_read)date|=0x01;dclk_0;din_1;dclk_1;return date;/*主函数*/int main()unsigned char i,j,k;DDRA=0xfb;PORTA=0x04;init_ch451();init_lcd();_delay_ms(1);while(1)temp=read_ch451();