51 单片机 max30102 驱动代码

以下是基于51单片机的max30102驱动代码，仅供参考：

#include <reg52.h>
#include <intrins.h>

#define I2C_SCL_PIN P1_7
#define I2C_SDA_PIN P1_6
#define I2C_READ_ACK 0
#define I2C_READ_NACK 1

sbit PIN_SCL = I2C_SCL_PIN;
sbit PIN_SDA = I2C_SDA_PIN;

void delay_us(unsigned int us)
{
    while (us--)
    {
        _nop_();
        _nop_();
        _nop_();
        _nop_();
    }
}

void i2c_start()
{
    PIN_SDA = 1;
    delay_us(2);
    PIN_SCL = 1;
    delay_us(2);
    PIN_SDA = 0;
    delay_us(2);
    PIN_SCL = 0;
    delay_us(2);
}

void i2c_stop()
{
    PIN_SDA = 0;
    delay_us(2);
    PIN_SCL = 1;
    delay_us(2);
    PIN_SDA = 1;
    delay_us(2);
}

void i2c_write_byte(unsigned char data)
{
    unsigned char i;
    for (i = 0; i < 8; i++)
    {
        PIN_SCL = 0;
        delay_us(2);
        PIN_SDA = (data & 0x80) ? 1 : 0;
        delay_us(2);
        PIN_SCL = 1;
        delay_us(2);
        data <<= 1;
    }
    PIN_SCL = 0;
    delay_us(2);
    PIN_SDA = 1;
    delay_us(2);
}

unsigned char i2c_read_byte(unsigned char ack)
{
    unsigned char i, data = 0;
    for (i = 0; i < 8; i++)
    {
        PIN_SCL = 0;
        delay_us(2);
        PIN_SCL = 1;
        delay_us(2);
        data <<= 1;
        data |= PIN_SDA;
    }
    PIN_SCL = 0;
    delay_us(2);
    PIN_SDA = ack ? 1 : 0;
    delay_us(2);
    PIN_SCL = 1;
    delay_us(2);
    PIN_SCL = 0;
    delay_us(2);
    PIN_SDA = 1;
    delay_us(2);
    return data;
}

void max30102_write_reg(unsigned char reg, unsigned char data)
{
    i2c_start();
    i2c_write_byte(0xAE);
    i2c_write_byte(reg);
    i2c_write_byte(data);
    i2c_stop();
}

unsigned char max30102_read_reg(unsigned char reg)
{
    unsigned char data;
    i2c_start();
    i2c_write_byte(0xAE);
    i2c_write_byte(reg);
    i2c_start();
    i2c_write_byte(0xAF);
    data = i2c_read_byte(I2C_READ_NACK);
    i2c_stop();
    return data;
}

void max30102_init()
{
    max30102_write_reg(0x09, 0x03); // FIFO Configuration: Sample Average = 4, FIFO Rolls on Full, 16 bit ADC resolution
    max30102_write_reg(0x0A, 0x47); // LED1 pulse amplitude = 0x1F (max), LED2 pulse amplitude = 0x1F (max)
    max30102_write_reg(0x0C, 0x04); // MODE Configuration: Mode = Red + IR
    max30102_write_reg(0x02, 0x00); // Set RLED Current
    max30102_write_reg(0x03, 0x00); // Set IRLED Current
    max30102_write_reg(0x05, 0x00); // Set ADC Range
}

void max30102_read_fifo(unsigned char *data_buf)
{
    unsigned char i, data;
    i2c_start();
    i2c_write_byte(0xAE);
    i2c_write_byte(0x00);
    i2c_start();
    i2c_write_byte(0xAF);
    for (i = 0; i < 6; i++)
    {
        data = i2c_read_byte(I2C_READ_ACK);
        *data_buf++ = data;
    }
    data = i2c_read_byte(I2C_READ_NACK);
    *data_buf = data;
    i2c_stop();
}

void main()
{
    unsigned char data_buf[7];
    max30102_init();
    while (1)
    {
        max30102_read_fifo(data_buf);
        // 处理数据
    }
}

该代码使用了基于软件的I2C协议实现，如果需要使用硬件I2C，可以根据硬件的具体情况进行修改。同时，该代码只实现了max30102的读取功能，如果需要写入其他寄存器，可以根据需要进行修改。