+# BME280 sensor API
+## Introduction
+This package contains the Bosch Sensortec's BME280 pressure sensor driver (sensor API)
-CONTENTS OF THIS FILE
-=======================
- * Introduction
- * Version
- * Integration details
- * Driver files information
- * Supported sensor interface
- * Copyright
-
-INTRODUCTION
-===============
- - This package contains the Bosch Sensortec MEMS humidity sensor driver(sensor API)
- - The sensor driver package includes bme280.h, bme280.c and bme280_support.c files
-
-VERSION
-=========
- - Version of bme280 sensor driver is:
- * bme280.c - V2.0.5
- * bme280.h - V2.0.5
- * bme280_support.c - V1.0.6
-
-INTEGRATION DETAILS
-=====================
- - Integrate bme280.h and bme280.c file in to your project.
- - The bme280_support.c file contains only examples for API use cases, so it is not required to integrate into project.
-
-DRIVER FILES INFORMATION
-===========================
- bme280.h
- -----------
- * This header file has the register address definition, constant definitions, data type definition and supported sensor driver calls declarations.
-
- bme280.c
- ------------
- * This file contains the implementation for the sensor driver APIs.
-
- bme280_support.c
- ----------------------
- * This file shall be used as an user guidance, here you can find samples of
- * Initialize the sensor with I2C/SPI communication
- - Add your code to the SPI and/or I2C bus read and bus write functions.
- - Return value can be chosen by yourself
- - API just passes that value to your application code
- - Add your code to the delay function
- - Change I2C address accordingly in bme280.h
- * Power mode configuration of the sensor
- * Get and set functions usage
- * Reading the sensor read out data
-
-SUPPORTED SENSOR INTERFACE
-====================================
- - This humidity sensor driver supports SPI and I2C interfaces
-
-
-COPYRIGHT
-===========
- - Copyright (C) 2013 - 2016 Bosch Sensortec GmbH
+The sensor driver package includes bme280.c, bme280.h and bme280_defs.h files.
+## Version
+File | Version | Date
+-----|---------|-----
+bme280.c | 3.2.0 | 21 Mar 2017
+bme280.h | 3.2.0 | 21 Mar 2017
+bme280_defs.h | 3.2.0 | 21 Mar 2017
-
+## Integration details
+* Integrate bme280.h, bme280_defs.h and bme280.c file in to the project.
+* Include the bme280.h file in your code like below.
+``` c
+#include "bme280.h"
+```
+
+## File information
+* bme280_defs.h : This header file has the constants, macros and datatype declarations.
+* bme280.h : This header file contains the declarations of the sensor driver APIs.
+* bme280.c : This source file contains the definitions of the sensor driver APIs.
+
+## Supported sensor interfaces
+* SPI 4-wire
+* I2C
+
+SPI 3-wire is currently not supported in the API.
+## Usage guide
+### Initializing the sensor
+To initialize the sensor, user need to create a device structure. User can do this by
+creating an instance of the structure bme280_dev. After creating the device strcuture, user
+need to fill in the various parameters as shown below.
+
+#### Example for SPI 4-Wire
+``` c
+struct bme280_dev dev;
+int8_t rslt = BME280_OK;
+
+/* Sensor_0 interface over SPI with native chip select line */
+dev.id = 0;
+dev.interface = BME280_SPI_INTF;
+dev.read = user_spi_read;
+dev.write = user_spi_write;
+dev.delay_ms = user_delay_ms;
+
+rslt = bme280_init(&dev);
+```
+#### Example for I2C
+``` c
+struct bme280_dev dev;
+int8_t rslt = BME280_OK;
+
+dev.id = BME280_I2C_ADDR_PRIM;
+dev.interface = BME280_I2C_INTF;
+dev.read = user_i2c_read;
+dev.write = user_i2c_write;
+dev.delay_ms = user_delay_ms;
+
+rslt = bme280_init(&dev);
+```
+Regarding compensation functions for temperature,pressure and humidity we have two implementations.
+1) Double precision floating point version
+2) Integer version
+
+By default, integer version is used in the API. If user needs double version, user has to
+enable FLOATING_POINT_REPRESENTATION macro in bme280_defs.h file.
+
+In integer compensation functions, we also have below two implementations for pressure.
+1) For 32 bit machine.
+2) For 64 bit machine.
+By default, 64 bit variant is used in the API. If user wants 32 bit variant, user can disable the
+macro MACHINE_64_BIT in bme280_defs.h file.
+### Get sensor data
+#### Get sensor data in forced mode
+
+``` c
+int8_t get_sensor_data_forced_mode(struct bme280_dev *dev)
+{
+ int8_t rslt;
+ uint8_t settings_sel;
+ struct bme280_data comp_data;
+
+ /* Continuously get the sensor data */
+ while (1) {
+ dev->settings.osr_h = BME280_OVERSAMPLING_4X;
+ dev->settings.osr_p = BME280_OVERSAMPLING_4X;
+ dev->settings.osr_t = BME280_OVERSAMPLING_4X;
+
+ settings_sel = BME280_OSR_PRESS_SEL|BME280_OSR_TEMP_SEL|BME280_OSR_HUM_SEL;
+
+ rslt = bme280_set_sensor_settings(settings_sel, dev);
+ rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
+ /* Give some delay for the sensor to go into force mode */
+ dev->delay_ms(5);
+ rslt = bme280_get_sensor_data(BME280_PRESS | BME280_HUM | BME280_TEMP, &comp_data, dev);
+ print_sensor_data(&comp_data);
+ }
+ return rslt;
+}
+
+void print_sensor_data(struct bme280_data *comp_data)
+{
+#ifdef FLOATING_POINT_REPRESENTATION
+ printf("%0.2f\t\t%0.2f\t\t%0.2f\t\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#else
+ printf("%ld\t\t%ld\t\t%ld\t\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#endif
+}
+
+```
+##### Get sensor data in normal mode
+``` c
+int8_t get_sensor_data_normal_mode(struct bme280_dev *dev)
+{
+ int8_t rslt;
+ uint8_t settings_sel;
+ struct bme280_data comp_data;
+
+ dev->settings.osr_h = BME280_OVERSAMPLING_4X;
+ dev->settings.osr_p = BME280_OVERSAMPLING_4X;
+ dev->settings.osr_t = BME280_OVERSAMPLING_4X;
+
+ settings_sel = BME280_OSR_PRESS_SEL|BME280_OSR_TEMP_SEL|BME280_OSR_HUM_SEL;
+ rslt = bme280_set_sensor_settings(settings_sel, dev);
+ rslt = bme280_set_sensor_mode(BME280_NORMAL_MODE, dev);
+ /* Give some delay for the sensor to go into normal mode */
+ dev->delay_ms(5);
+ while (1) {
+ rslt = bme280_get_sensor_data(BME280_PRESS | BME280_HUM | BME280_TEMP, &comp_data, dev);
+ print_sensor_data(&comp_data);
+ }
+
+ return rslt;
+}
+
+void print_sensor_data(struct bme280_data *comp_data)
+{
+#ifdef FLOATING_POINT_REPRESENTATION
+ printf("%0.2f\t\t%0.2f\t\t%0.2f\t\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#else
+ printf("%ld\t\t%ld\t\t%ld\t\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#endif
+}
+```
+
+## Copyright (C) 2016 - 2017 Bosch Sensortec GmbH
\ No newline at end of file
projects / BME280_driver / blobdiff