bar_bmp585.c

Go to the documentation of this file.

/*
 * bar_bmp585.c
 *
 *  Created on: 16. 2. 2026
 *      Author: Milan
 */
 
#include "bar_bmp585.h"
 
#ifdef SENSOR_BAR_BMP585
 
#include "i2c.h"
#include "utils/mydefs.h"
#include "mymems.h"
#include "mysensors_base.h"
#include <stdio.h>
#include <math.h>
#include "tmphm_sht45.h"    // because of formula to sea level
 
// BMP585 I2C Address (SDO connected to GND by default)
#define BMP585_I2C_ADDR    (0x46 << 1)
 
// Register Map
#define REG_CHIP_ID          0x01
#define REG_STATUS           0x28
#define REG_DATA_0           0x20  // Pressure data start
#define REG_DATA_1           0x21
#define REG_DATA_2           0x22
#define REG_TEMP_DATA_0      0x1D  // Temperature data start
#define REG_TEMP_DATA_1      0x1E
#define REG_TEMP_DATA_2      0x1F
#define REG_OSR_CONFIG       0x36
#define REG_ODR_CONFIG       0x37
#define REG_INT_CONFIG       0x38
#define REG_IF_CONFIG        0x39
#define REG_CMD              0x7E
 
// Chip ID value
#define BMP585_CHIP_ID       0x50
 
// Power modes
#define BAR_MODE_STANDBY     0x00
#define BAR_MODE_NORMAL      0x01
#define BAR_MODE_FORCED      0x02
#define BAR_MODE_DEEP_SLEEP  0x00  // Deep sleep is achieved via standby with specific config
 
bar_bmp585_t _bar_bmp585Data = {};
bar_bmp585_t _bck_bar_bmp585Data = {};  // backup
static uint8_t _isBarometer = 0;
 
/**
 * @brief Check if sensor is turned on
 */
static HAL_StatusTypeDef bar_bmp585_IsOn(I2C_HandleTypeDef *hi2c, uint8_t *onOff)
{
    HAL_StatusTypeDef status = HAL_ERROR;
 
    if (_isBarometer)
    {
        // Reading power control register
        uint8_t pwr_ctrl = 0x00;
        status = HAL_I2C_Mem_Read(hi2c, BMP585_I2C_ADDR, REG_ODR_CONFIG, 1, &pwr_ctrl, 1, 100);
        if (status == HAL_OK)
            if (onOff != 0)
                *onOff = ((pwr_ctrl & 0x1F) != 0);  // Check if ODR is set (not in standby)
    }
    return status;
}
 
/**
 * @brief Control sensor power mode
 */
static HAL_StatusTypeDef barometer_onOff(I2C_HandleTypeDef *hi2c, uint8_t onOff)
{
    HAL_StatusTypeDef status = HAL_ERROR;
 
    if (_isBarometer)
    {
        // Configure ODR_CONFIG register
        // onOff = 0x00 for standby/deep sleep
        // onOff = 0x18 for normal mode with 50Hz ODR
        uint8_t odr_config = onOff;
        status = HAL_I2C_Mem_Write(hi2c, BMP585_I2C_ADDR, REG_ODR_CONFIG, 1, &odr_config, 1, 100);
        _isBarometer = (status == HAL_OK);
    }
    return status;
}
 
int8_t bar_bmp585_Is(I2C_HandleTypeDef *hi2c, int8_t tryInit)
{
    if (!_isBarometer && tryInit)
        bar_bmp585_Init(hi2c);
    return _isBarometer;
}
 
HAL_StatusTypeDef bar_bmp585_On(I2C_HandleTypeDef *hi2c)
{
    // Configure ODR_CONFIG for normal operation
    // 0x18 = 00011000 -> ODR: 50Hz (bits 0-4 = 11000)
    const uint8_t val = 0x18;
    HAL_StatusTypeDef status = barometer_onOff(hi2c, val);
 
    _bar_bmp585Data.IsDataValid = 0;
    if (status == HAL_OK)
    {
        _memsMainBlock.Sens_BarometerStart++;
        mems_WriteMainBlock();
    }
    return status;
}
 
HAL_StatusTypeDef bar_bmp585_Off(I2C_HandleTypeDef *hi2c)
{
    // Configure ODR_CONFIG for deep sleep (standby mode)
    // 0x00 = 00000000 -> ODR: standby/deep sleep
    return barometer_onOff(hi2c, 0x00);
}
 
HAL_StatusTypeDef bar_bmp585_Init(I2C_HandleTypeDef *hi2c)
{
    HAL_StatusTypeDef status = I2C_IsDeviceReadyMT(hi2c, BMP585_I2C_ADDR, 2, 2);    // first check
 
    if (status == HAL_OK)
        do
        {
            // Check CHIP_ID
            uint8_t data = 0;
            if ((status = HAL_I2C_Mem_Read(hi2c, BMP585_I2C_ADDR, REG_CHIP_ID, 1, &data, 1, 100)) != HAL_OK)
                break;
            if (data != BMP585_CHIP_ID)
            {
                status = HAL_ERROR;
                break;
            }
            _isBarometer = 1; // because On/Off needs it
 
            // Configure oversampling settings (OSR_CONFIG)
            // 0x00 = no oversampling for quick startup
            uint8_t osr_config = 0x00;
            if ((status = HAL_I2C_Mem_Write(hi2c, BMP585_I2C_ADDR, REG_OSR_CONFIG, 1, &osr_config, 1, 100)) != HAL_OK)
                break;
 
            // Check turning on/off
            if ((status = bar_bmp585_On(hi2c)) != HAL_OK)
                break;
            if ((status = bar_bmp585_Off(hi2c)) != HAL_OK)
                break;
        } while (0);
    _isBarometer = (status == HAL_OK);
 
    return status;
}
 
HAL_StatusTypeDef bar_bmp585_Read(I2C_HandleTypeDef *hi2c)
{
    uint8_t raw_data[6]; // 3 bytes for pressure, 3 for temperature
    HAL_StatusTypeDef status = HAL_ERROR;
 
    if (_isBarometer)
    {
        do
        {
            // Check if sensor is turned on
            if ((status = bar_bmp585_IsOn(hi2c, &raw_data[0])) != HAL_OK)
                break;
            if (!raw_data[0])
            {
                status = HAL_TIMEOUT;
                break;
            }
 
            // Read Pressure (3 bytes) starting from DATA_0
            if ((status = HAL_I2C_Mem_Read(hi2c, BMP585_I2C_ADDR, REG_DATA_0, 1, raw_data, 3, 100)) != HAL_OK)
                break;
 
            // Process Pressure (24-bit)
            uint32_t raw_press = ((uint32_t)raw_data[2] << 16) | ((uint32_t)raw_data[1] << 8) | raw_data[0];
            
            // Convert to hPa (output is in Pa * 64, so divide by 64 and then by 100 to get hPa)
            _bar_bmp585Data.PressureSEA = _bar_bmp585Data.PressureABS = (float)raw_press / 6400.0f;
 
            // Read Temperature (3 bytes) starting from TEMP_DATA_0
            if ((status = HAL_I2C_Mem_Read(hi2c, BMP585_I2C_ADDR, REG_TEMP_DATA_0, 1, &raw_data[3], 3, 100)) != HAL_OK)
                break;
 
            // Process Temperature (24-bit)
            uint32_t raw_temp = ((uint32_t)raw_data[5] << 16) | ((uint32_t)raw_data[4] << 8) | raw_data[3];
            
            // Convert to Celsius (output is in Celsius * 65536, so divide by 65536)
            _bar_bmp585Data.Temperature = (float)raw_temp / 65536.0f;
            _bar_bmp585Data.IsDataValid = 1;
 
            /*
             * Calculate Sea Level Pressure
             * Using barometric formula to convert station pressure to sea level pressure
             * Psea = Pstation * [1 - (0.0065 * h) / (T + 273.15 + 0.0065 * h)]^(-5.257)
             * 
             * Where:
             * Pstation = measured pressure in hPa
             * h = altitude in meters
             * T = temperature in °C
             */
            // Relative pressure needs temperature value
            if (_systemParams.SensAltitude > 0)
            {
#ifdef SENSOR_SHT45
                float temp = (_tmphm_sht45Data.IsDataValid) ? _tmphm_sht45Data.Temperature : _bar_bmp585Data.Temperature;
#else
                float temp = _bar_bmp585Data.Temperature;
#endif
                _bar_bmp585Data.PressureSEA = _bar_bmp585Data.PressureABS
                        * pow(1.0 - (0.0065 * _systemParams.SensAltitude) / (temp + (0.0065 * _systemParams.SensAltitude) + 273.15), -5.257);
            }
        } while (0);
    }
    return status;
}
 
void bar_bmp585_LogData(char *buf)
{
    if (buf != NULL)
        sprintf(buf, "|barometer ABS:" PRIf_02 ", SEA:" PRIf_02 ", temp:" PRIf_02 " ", PRIf_02D(_bar_bmp585Data.PressureABS), PRIf_02D(_bar_bmp585Data.PressureSEA),
                PRIf_02D(_bar_bmp585Data.Temperature));
}
 
#endif