#include "main.h" #include <string.h> #define DIGITAL_NUMBER ( 4 ) typedef struct{ char ch; uint8_t digital_code; }digital_code_t; static uint8_t display_buf[DIGITAL_NUMBER]; static code digital_code_t digital_code[] = { {' ', 0x00},///<固定为不显示 {'0', 0x3f}, {'1', 0x06}, {'2', 0x5b}, {'3', 0x4f}, {'4', 0x66}, {'5', 0x6d}, {'6', 0x7d}, {'7', 0x07}, {'8', 0x7f}, {'9', 0x6f}, {'A', 0x77}, {'b', 0x7c}, {'C', 0x39}, {'d', 0x5e}, {'E', 0x79}, {'F', 0x71}, {'-', 0x40}, {'H', 0x76}, {'L', 0x38}, }; static void send_digital_code(uint8_t pos, uint8_t digital_code) { P2 &= 0xf0; P2 |= (1 << pos); P0 = ~digital_code;///<发段选信号 } void digital_display_poll(void) { static uint8_t digital_channel = 0; send_digital_code(digital_channel, display_buf[digital_channel]); digital_channel = (++digital_channel) % DIGITAL_NUMBER; } static uint8_t find_digital_code(char ch) { uint8_t i; for(i = 0; i < (sizeof(digital_code) / sizeof(digital_code[0])); i++){ if(ch == digital_code[i].ch){ return digital_code[i].digital_code; } } return digital_code[0].digital_code;//} void update_digital_display(char *buf) { uint8_t len; uint8_t i; uint8_t point_num = 0; uint8_t display_len; uint8_t display_pos; if(buf == NULL){ return; } len = strlen(buf); for(i = 0; i < len; i++){ if(buf[i] == '.'){ ++point_num; } } display_len = len - point_num; if(display_len > DIGITAL_NUMBER){ return; } for(i = 0; i < (DIGITAL_NUMBER - display_len); i++){ display_buf[i] = digital_code[0].digital_code; } display_pos = i; for(i = 0; i < len; i++){ if(buf[i] != '.'){ display_buf[display_pos] = find_digital_code(buf[i]); ++display_pos; }else{ display_buf[display_pos - 1] |= 0x80;//display_buf[display_pos - 1] &= 0x7f; } } } 给这段程序加注释

这段程序是一个数字显示模块的驱动程序，通过控制数字管的段选和位选实现数字的显示。下面是注释：

#include "main.h"
#include <string.h>

#define DIGITAL_NUMBER    ( 4 )   ///<数字管的个数

typedef struct{   ///<数字对应的编码结构体
    char ch;   ///<数字或字符
    uint8_t digital_code; ///<编码值
}digital_code_t;

static uint8_t display_buf[DIGITAL_NUMBER]; ///<数字管的显示缓存
static code digital_code_t digital_code[] = {   ///<数字对应的编码表
    {' ', 0x00},///<固定为不显示
    {'0', 0x3f},
    {'1', 0x06},
    {'2', 0x5b},
    {'3', 0x4f},
    {'4', 0x66},
    {'5', 0x6d},
    {'6', 0x7d},
    {'7', 0x07},
    {'8', 0x7f},
    {'9', 0x6f},
    {'A', 0x77},
    {'b', 0x7c},
    {'C', 0x39},
    {'d', 0x5e},
    {'E', 0x79},
    {'F', 0x71},
    {'-', 0x40},
    {'H', 0x76},
    {'L', 0x38},
};

static void send_digital_code(uint8_t pos, uint8_t digital_code) {   ///<发送数字编码到数字管
    P2 &= 0xf0;///<清除位选信号
    P2 |= (1 << pos);///<设置当前位选信号
    P0 = ~digital_code;///<将数字编码取反作为段选信号
}

void digital_display_poll(void) {   ///<数字管轮询函数
    static uint8_t digital_channel = 0;///<当前位选通道
    send_digital_code(digital_channel, display_buf[digital_channel]);///<发送数字编码
    digital_channel = (++digital_channel) % DIGITAL_NUMBER;///<更新位选通道
}

static uint8_t find_digital_code(char ch) {   ///<根据数字或字符查找其编码值
    uint8_t i;
    for(i = 0; i < (sizeof(digital_code) / sizeof(digital_code[0])); i++){
        if(ch == digital_code[i].ch){
            return digital_code[i].digital_code;
        }
    }
    return digital_code[0].digital_code;
}

void update_digital_display(char *buf) {   ///<更新数字管显示
    uint8_t len;
    uint8_t i;
    uint8_t point_num = 0;///<小数点个数
    uint8_t display_len;///<显示长度
    uint8_t display_pos;///<当前显示位置

    if(buf == NULL){///<判断输入参数是否合法
        return;
    }

    len = strlen(buf);
    for(i = 0; i < len; i++){///<统计小数点个数
        if(buf[i] == '.'){
            ++point_num;
        }
    }
    display_len = len - point_num;///<计算显示长度
    if(display_len > DIGITAL_NUMBER){///<长度超过数字管个数则退出
        return;
    }
    for(i = 0; i < (DIGITAL_NUMBER - display_len); i++){///<在前面加空格
        display_buf[i] = digital_code[0].digital_code;
    }
    display_pos = i;
    for(i = 0; i < len; i++){
        if(buf[i] != '.'){///<不是小数点则查找数字编码值
            display_buf[display_pos] = find_digital_code(buf[i]);
            ++display_pos;
        }else{///<是小数点则标记当前数字编码为小数点
            display_buf[display_pos - 1] |= 0x80;///<将最高位设置为1
        }
    }
}