51单片机通过蓝牙对ds1302调时的代码

以下是一个简单的示例代码，使用51单片机通过蓝牙对DS1302实时时钟芯片进行调时：

#include <reg51.h>
#include <stdio.h>
#include <string.h>

#define FOSC 11059200L
#define BAUD 9600
#define TIMER0_RELOAD_VALUE 256 - (FOSC / 12 / BAUD)

sbit SCK = P1^0;
sbit DSIO = P1^1;
sbit RST = P1^2;

unsigned char time[7];
unsigned char receive_buf[20];
unsigned char receive_len;

void delay(unsigned int t)
{
    while(t--);
}

void send_byte(unsigned char byte)
{
    unsigned char i;

    for(i = 0; i < 8; i++)
    {
        DSIO = byte & 0x01;
        byte >>= 1;
        SCK = 1;
        SCK = 0;
    }
}

unsigned char receive_byte()
{
    unsigned char i;
    unsigned char byte = 0;

    for(i = 0; i < 8; i++)
    {
        byte >>= 1;
        if(DSIO)
            byte |= 0x80;
        SCK = 1;
        SCK = 0;
    }

    return byte;
}

void init_ds1302()
{
    RST = 0;
    delay(100);
    RST = 1;
    send_byte(0x8e);
    send_byte(0);
    send_byte(0x80);
}

void write_ds1302(unsigned char reg, unsigned char val)
{
    send_byte(0x8e);
    send_byte(reg);
    send_byte(val);
}

unsigned char read_ds1302(unsigned char reg)
{
    send_byte(0x8e);
    send_byte(reg);
    return receive_byte();
}

void read_time()
{
    unsigned char i;

    for(i = 0; i < 7; i++)
        time[i] = read_ds1302(i + 1);
}

void write_time()
{
    unsigned char i;

    write_ds1302(0x80, 0);
    for(i = 0; i < 7; i++)
        write_ds1302(i + 1, time[i]);
    write_ds1302(0x80, 0x80);
}

void uart_init()
{
    TMOD = 0x20;
    TH1 = TIMER0_RELOAD_VALUE;
    TL1 = TIMER0_RELOAD_VALUE;
    PCON = 0x00;
    TR1 = 1;
    SM0 = 0;
    SM1 = 1;
    REN = 1;
}

void uart_send(unsigned char byte)
{
    SBUF = byte;
    while(TI == 0);
    TI = 0;
}

void uart_send_string(unsigned char *str)
{
    unsigned char i;

    for(i = 0; i < strlen(str); i++)
        uart_send(str[i]);
}

void uart_receive() interrupt 4
{
    if(RI == 1)
    {
        receive_buf[receive_len] = SBUF;
        receive_len++;
        RI = 0;
    }
}

void parse_command()
{
    unsigned char i;

    if(strncmp(receive_buf, "time", 4) == 0)
    {
        read_time();
        for(i = 0; i < 6; i++)
            uart_send(time[i]);
    }
    else if(strncmp(receive_buf, "set", 3) == 0)
    {
        time[0] = receive_buf[4] & 0x7f;
        time[1] = receive_buf[6] & 0x7f;
        time[2] = receive_buf[8] & 0x3f;
        time[3] = receive_buf[10] & 0x3f;
        time[4] = receive_buf[12] & 0x1f;
        time[5] = receive_buf[14] & 0x7f;
        write_time();
        uart_send_string("OK");
    }
    else
        uart_send_string("Invalid command");
}

void main()
{
    uart_init();
    init_ds1302();
    EA = 1;
    ES = 1;

    while(1)
    {
        if(receive_len > 0)
        {
            parse_command();
            receive_buf[0] = 0;
            receive_len = 0;
        }
    }
}

在这个例子中，我们使用P1口的0、1、2三个引脚分别连接DS1302时钟芯片的SCLK、IO、RST引脚，使用串口通信模块进行蓝牙通信。我们可以通过发送类似“set 21 01 01 12 00 00”这样的指令来设置DS1302的时间，或者通过发送“time”指令来读取当前的时间。