This package contains the Bosch Sensortec's BMP3 pressure sensor driver (sensor API)
The sensor driver package includes bmp3.h, bmp3.c and bmp3_defs.h files
| File | Version | Date |
|---|---|---|
| bmp3.c | 1.1.3 | 01 July 2019 |
| bmp3.h | 1.1.3 | 01 July 2019 |
| bmp3_defs.h | 1.1.3 | 01 July 2019 |
- Integrate bmp3.h, bmp3_defs.h and bmp3.c file in to your project.
- Include the bmp3.h file in your code like below.
#include "bmp3.h"- bmp3_defs.h : This header file has the constants, macros and datatype declarations.
- bmp3.h : This header file contains the declarations of the sensor driver APIs.
- bmp3.c : This source file contains the definitions of the sensor driver APIs.
- SPI 4-wire
- I2C
To initialize the sensor, you will first need to create a device structure. You can do this by creating an instance of the structure bmp3_dev. Then go on to fill in the various parameters as shown below.
Regarding Compensation functions for temperature and pressure, we have two implementations.
- Double precision floating point version
- Integer version
If you want to use the floating point version, define the BMP3_DOUBLE_PRECISION_COMPENSATION macro in your makefile or uncomment the relevant line in the bmp3_defs.h file. By default, the integer version will be used. Below example code uses floating point representation.
struct bmp3_dev dev;
int8_t rslt = BMP3_OK;
/* Sensor_0 interface over SPI with native chip select line */
dev.dev_id = 0;
dev.intf = BMP3_SPI_INTF;
dev.read = user_spi_read;
dev.write = user_spi_write;
dev.delay_ms = user_delay_ms;
rslt = bmp3_init(&dev);struct bmp3_dev dev;
int8_t rslt = BMP3_OK;
dev.dev_id = BMP3_I2C_ADDR_PRIM;
dev.intf = BMP3_I2C_INTF;
dev.read = user_i2c_read;
dev.write = user_i2c_write;
dev.delay_ms = user_delay_ms;
rslt = bmp3_init(&dev);int8_t set_forced_mode(struct bmp3_dev *dev)
{
int8_t rslt;
/* Used to select the settings user needs to change */
uint16_t settings_sel;
/* Select the pressure and temperature sensor to be enabled */
dev->settings.press_en = BMP3_ENABLE;
dev->settings.temp_en = BMP3_ENABLE;
/* Assign the settings which needs to be set in the sensor */
settings_sel = BMP3_PRESS_EN_SEL | BMP3_TEMP_EN_SEL;
/* Write the settings in the sensor */
rslt = bmp3_set_sensor_settings(settings_sel, dev);
/* Select the power mode */
dev->settings.op_mode = BMP3_FORCED_MODE;
/* Set the power mode in the sensor */
rslt = bmp3_set_op_mode(dev);
return rslt;
}int8_t set_forced_mode_with_osr(struct bmp3_dev *dev)
{
int8_t rslt;
/* Used to select the settings user needs to change */
uint16_t settings_sel;
/* Select the pressure and temperature sensor to be enabled */
dev->settings.press_en = BMP3_ENABLE;
dev->settings.temp_en = BMP3_ENABLE;
/* Select the oversampling settings for pressure and temperature */
dev->settings.odr_filter.press_os = BMP3_OVERSAMPLING_2X;
dev->settings.odr_filter.temp_os = BMP3_OVERSAMPLING_2X;
/* Assign the settings which needs to be set in the sensor */
settings_sel = BMP3_PRESS_EN_SEL | BMP3_TEMP_EN_SEL | BMP3_PRESS_OS_SEL | BMP3_TEMP_OS_SEL;
/* Write the settings in the sensor */
rslt = bmp3_set_sensor_settings(settings_sel, dev);
/* Select the power mode */
dev->settings.op_mode = BMP3_FORCED_MODE;
/* Set the power mode in the sensor */
rslt = bmp3_set_op_mode(dev);
return rslt;
}int8_t set_normal_mode(struct bmp3_dev *dev)
{
int8_t rslt;
/* Used to select the settings user needs to change */
uint16_t settings_sel;
/* Select the pressure and temperature sensor to be enabled */
dev->settings.press_en = BMP3_ENABLE;
dev->settings.temp_en = BMP3_ENABLE;
/* Select the output data rate and oversampling settings for pressure and temperature */
dev->settings.odr_filter.press_os = BMP3_NO_OVERSAMPLING;
dev->settings.odr_filter.temp_os = BMP3_NO_OVERSAMPLING;
dev->settings.odr_filter.odr = BMP3_ODR_200_HZ;
/* Assign the settings which needs to be set in the sensor */
settings_sel = BMP3_PRESS_EN_SEL | BMP3_TEMP_EN_SEL | BMP3_PRESS_OS_SEL | BMP3_TEMP_OS_SEL | BMP3_ODR_SEL;
rslt = bmp3_set_sensor_settings(settings_sel, dev);
/* Set the power mode to normal mode */
dev->settings.op_mode = BMP3_NORMAL_MODE;
rslt = bmp3_set_op_mode(dev);
return rslt;
}int8_t get_sensor_data(struct bmp3_dev *dev)
{
int8_t rslt;
/* Variable used to select the sensor component */
uint8_t sensor_comp;
/* Variable used to store the compensated data */
struct bmp3_data data;
/* Sensor component selection */
sensor_comp = BMP3_PRESS | BMP3_TEMP;
/* Temperature and Pressure data are read and stored in the bmp3_data instance */
rslt = bmp3_get_sensor_data(sensor_comp, &data, dev);
/* Print the temperature and pressure data */
printf("Temperature in deg celsius\t Pressure in Pascal\t\n");
#ifdef BMP3_DOUBLE_PRECISION_COMPENSATION
printf("%0.2f\t\t %0.2f\t\t\n",data.temperature, data.pressure);
#else
/* for fixed point the compensated temperature and pressure output has a multiplication factor of 100 */
printf("%lld\t\t %llu\t\t\n",data.temperature, data.pressure);
#endif
return rslt;
}int8_t configure_and_get_fifo_data(struct bmp3_dev *dev)
{
int8_t rslt;
/* Loop Variable */
uint8_t i;
/* FIFO object to be assigned to device structure */
struct bmp3_fifo fifo;
/* Pressure and temperature array of structures with maximum frame size */
struct bmp3_data sensor_data[73] = {0};
/* Used to select the settings user needs to change */
uint16_t settings_sel;
/* try count for polling the watermark interrupt status */
uint8_t try_count;
/* Enable fifo */
fifo.settings.mode = BMP3_ENABLE;
/* Enable Pressure sensor for fifo */
fifo.settings.press_en = BMP3_ENABLE;
/* Enable temperature sensor for fifo */
fifo.settings.temp_en = BMP3_ENABLE;
/* Enable fifo time */
fifo.settings.time_en = BMP3_ENABLE;
/* No subsampling for FIFO */
fifo.settings.down_sampling = BMP3_FIFO_NO_SUBSAMPLING;
/* FIFO watemrmark interrupt enable */
fifo.settings.fwtm_en = BMP3_ENABLE;
/* Link the fifo object to device structure */
dev->fifo = &fifo;
/* Select the settings required for fifo */
settings_sel = BMP3_FIFO_MODE_SEL | BMP3_FIFO_TIME_EN_SEL | BMP3_FIFO_TEMP_EN_SEL |
BMP3_FIFO_PRESS_EN_SEL | BMP3_FIFO_DOWN_SAMPLING_SEL | BMP3_FIFO_FWTM_EN_SEL;
/* Set the selected settings in fifo */
rslt = bmp3_set_fifo_settings(settings_sel, dev);
/* Set the number of frames to be read so as to set the watermark length in the sensor */
dev->fifo->data.req_frames = 50;
rslt = bmp3_set_fifo_watermark(dev);
/* Set the power mode to normal */
rslt = set_normal_mode(dev);
/* TODO : To calculate the exact time for try count variable */
try_count = 0xFFFF;
/* Poll till watermark level is reached in fifo */
do {
rslt = bmp3_get_status(dev);
try_count--;
} while ((dev->status.intr.fifo_wm == 0) && (try_count > 0));
if (try_count > 0) {
rslt = bmp3_get_fifo_data(dev);
rslt = bmp3_extract_fifo_data(sensor_data, dev);
printf("FIFO data\n");
printf("Temp in deg celsius \tPress in Pascal\n");
/* Print the fifo data */
for (i = 0; i < dev->fifo->data.req_frames; i++) {
#ifdef BMP3_DOUBLE_PRECISION_COMPENSATION
printf("%0.2f\t%0.2f\n", sensor_data[i].temperature,sensor_data[i].pressure);
#else
/* for fixed point the compensated temperature and pressure output has a multiplication factor of 100 */
printf("%lld\t%llu\n", sensor_data[i].temperature,sensor_data[i].pressure);
#endif
}
} else {
rslt = BMP3_E_FIFO_WATERMARK_NOT_REACHED;
}
return rslt;
}