Hi,
When reading the FIFO buffer though I2C read command, we typically retrieve 6 bytes of data: 3 bytes for the Red LED value and 3 bytes for the IR LED value.
The question is: how is the data arranged in the 6-byte buffer?
Is it organized such that bytes 0 to 2 represent the Red LED data, and bytes 3 to 5 represent the IR LED data?
I'm a bit confused about how the data is arranged when reading multiple bytes. Could you clarify the orientation of the data in the buffer?
uint8_t maxim_max30102_read_fifo(uint32_t *pun_red_led, uint32_t *pun_ir_led)
/**
* \brief Read a set of samples from the MAX30102 FIFO register
* \par Details
* This function reads a set of samples from the MAX30102 FIFO register
*
* \param[out] *pun_red_led - pointer that stores the red LED reading data
* \param[out] *pun_ir_led - pointer that stores the IR LED reading data
*
* \retval true on success
*/
{
uint32_t un_temp;
unsigned char uch_temp;
*pun_red_led=0;
*pun_ir_led=0;
unsigned char ach_i2c_data[6];
//read and clear status register
maxim_max30102_read_reg(REG_INTR_STATUS_1, &uch_temp);
maxim_max30102_read_reg(REG_INTR_STATUS_2, &uch_temp);
ach_i2c_data[0]=REG_FIFO_DATA;
HAL_I2C_GetState(&hi2c1);
//DMP library driver slave_addr address needs to be shifted 1 bit to the left when sending, the last bit or upper read/write bit
HAL_I2C_Mem_Read(&hi2c1, I2C_READ_ADDR, REG_FIFO_DATA, 1, ach_i2c_data, 6, HAL_MAX_DELAY);
un_temp=(unsigned char) ach_i2c_data[0];
un_temp<<=16;
*pun_red_led+=un_temp;
un_temp=(unsigned char) ach_i2c_data[1];
un_temp<<=8;
*pun_red_led+=un_temp;
un_temp=(unsigned char) ach_i2c_data[2];
*pun_red_led+=un_temp;
un_temp=(unsigned char) ach_i2c_data[3];
un_temp<<=16;
*pun_ir_led+=un_temp;
un_temp=(unsigned char) ach_i2c_data[4];
un_temp<<=8;
*pun_ir_led+=un_temp;
un_temp=(unsigned char) ach_i2c_data[5];
*pun_ir_led+=un_temp;
*pun_red_led&=0x03FFFF; //Mask MSB [23:18]
*pun_ir_led&=0x03FFFF; //Mask MSB [23:18]
return 1;
}
