56 lines
1.2 KiB
C
56 lines
1.2 KiB
C
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#include "hc165.h"
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//初始化74hc165
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void _74hc165_init(void)
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{
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HC165_INH_L(); //初始化使能时钟，后面就不需再使能
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HC165_LD_H(); //LD拉高，不读取按键状态
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HC165_CLK_H(); //时钟拉高，便于产生上升沿
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}
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unsigned int date_t = 0;
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//读取74HC165
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uint16_t _74hc165_read_byte(void)
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{
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unsigned char i;
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unsigned int temp = 0;
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HC165_LD_L(); //LD拉低，读取按键状态
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delay_tick(10);
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//delay_us(1);
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HC165_LD_H(); //LD拉高，停止按键读取
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delay_tick(10);
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//delay_us(1);
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if(HC165_DAT_OUT == 1) //等于1即并行输入D7引脚的按键被按下
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{
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temp |= 0x01; //最低位置1表示按键被按下，反之则没按键被按下
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}
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for(i = 0; i < 15; i ++) //因为最高位不用移位即可读取，故循环(8-1)次，依次把次高位移到最高位，第一级74HC165优先读取
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{
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temp = temp << 1;
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HC165_CLK_L(); //HC165_CLK = 0 ——> HC165_CLK = 1 产生上升沿，次高位D(n-1)移到高位D(n)
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delay_tick(10);
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//delay_us(1);
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HC165_CLK_H();
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delay_tick(5);
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//delay_us(1);
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if(HC165_DAT_OUT == 1)
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{
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temp |= 0x01;
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}
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delay_tick(5);
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//delay_us(5);
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}
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return temp;
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// date = temp;
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// date_t = temp;
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// //将16位数据分离为两个8位数据
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// date[0] = (unsigned char)(temp & 0x00ff); //第二级74HC165的数据
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// date[1] = (unsigned char)((temp >> 8) & 0x00ff);//第一级74HC165的数据
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}
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