[Raspberry Pi 3B+ Review] Open I2C peripheral interface & drive DS3231

donatello1996

[Raspberry Pi 3B+ Review] Open I2C peripheral interface & drive DS3231 [Copy link]

This post uses a very simple method to use the Raspberry Pi to communicate with the I2C device. The device is selected as the DS3231 with the I2C interface. Simply connect the DS3231 to the I2C-1 interface: First, enable the I2C peripheral interface of the Raspberry Pi, either in the desktop settings or in the BOOT configuration file: Then use the command line tool i2cdetect to detect the existence of the I2C interface and the I2C slave: i2cdetect -y 1 i2cdump -y 1 0x68 You can see that the first seven registers of DS3231 are time data, from 0x01 to 0x07, they are seconds, minutes, hours, days, months, and years. Then load the wiringPi library, read the time from the program and display it: #ifndef _DS3231_H_ #define _DS3231_H_ #include


unsigned char BCD_to_BYTE(unsigned char val)
//BCD转换为Byte
{
    return((val>>4)*10)+(val&0x0f);
}


unsigned char BYTE_to_BCD(unsigned char val)
//Byte码转换为BCD码
{
     return(((val%100)/10)<<4)|(val%10);
}


unsigned char fd_i2c_ds3231,hour,min,sec,day,year,month,date;


void DS3231_Init(int flag,unsigned char year,unsigned char month,unsigned char date,
                 unsigned char day,unsigned char hour,unsigned char min,unsigned char sec)
{
    fd_i2c_ds3231=wiringPiI2CSetup(0x68);
    if(flag)
    {
        wiringPiI2CWriteReg8(fd_i2c_ds3231,6,BYTE_to_BCD(year));
        wiringPiI2CWriteReg8(fd_i2c_ds3231,5,BYTE_to_BCD(month));
        wiringPiI2CWriteReg8(fd_i2c_ds3231,4,BYTE_to_BCD(date));
        wiringPiI2CWriteReg8(fd_i2c_ds3231,3,BYTE_to_BCD(day));
        wiringPiI2CWriteReg8(fd_i2c_ds3231,2,BYTE_to_BCD(hour));
        wiringPiI2CWriteReg8(fd_i2c_ds3231,1,BYTE_to_BCD(min));
        wiringPiI2CWriteReg8(fd_i2c_ds3231,0,BYTE_to_BCD(sec));
    }


}


void DS3231_Read()
{
    sec=wiringPiI2CReadReg8(fd_i2c_ds3231,0);
    sec=BCD_to_BYTE(sec);


    min=wiringPiI2CReadReg8(fd_i2c_ds3231,1);
    min=BCD_to_BYTE(min);


    hour=wiringPiI2CReadReg8(fd_i2c_ds3231,2);
    hour=BCD_to_BYTE(hour);


    day=wiringPiI2CReadReg8(fd_i2c_ds3231,3);


    date=wiringPiI2CReadReg8(fd_i2c_ds3231,4);
    date=BCD_to_BYTE(date);


    month=wiringPiI2CReadReg8(fd_i2c_ds3231,5);
    month=BCD_to_BYTE(month);


    year=wiringPiI2CReadReg8(fd_i2c_ds3231,6);
    year=BCD_to_BYTE(year);
}


#endif

看看效果：

lcofjp

Nice guy, well written, keep it up!