+# 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 - V2.0.3
- * bme280.h - V2.0.3
- * bme280_support.c - V1.0.4
-
-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 - 2014 Bosch Sensortec GmbH
-
-
-
-
-
-
+The sensor driver package includes bme280.c, bme280.h and bme280_defs.h files.
+
+## Version
+File | Version | Date
+--------------|---------|------------
+bme280.c | 3.3.6 | 08 Mar 2019
+bme280.h | 3.3.6 | 08 Mar 2019
+bme280_defs.h | 3.3.6 | 08 Mar 2019
+
+## 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.dev_id = 0;
+dev.intf = 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.dev_id = BME280_I2C_ADDR_PRIM;
+dev.intf = 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 the user needs the floating point version, the user has to uncomment BME280_FLOAT_ENABLE macro in bme280_defs.h file or add that to the compiler flags.
+
+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 the user wants 32 bit variant, the user can disable the
+macro BME280_64BIT_ENABLE in bme280_defs.h file.
+
+### Sensor data units
+> The sensor data units depends on the following macros being enabled or not,
+> (in bme280_defs.h file or as compiler macros)
+> * BME280_FLOAT_ENABLE
+> * BME280_64BIT_ENABLE
+
+In case of the macro "BME280_FLOAT_ENABLE" enabled,
+The outputs are in double and the units are
+
+ - °C for temperature
+ - % relative humidity
+ - Pascal for pressure
+
+In case if "BME280_FLOAT_ENABLE" is not enabled, then it is
+
+ - int32_t for temperature with the units 100 * °C
+ - uint32_t for humidity with the units 1024 * % relative humidity
+ - uint32_t for pressure
+ If macro "BME280_64BIT_ENABLE" is enabled, which it is by default, the unit is 100 * Pascal
+ If this macro is disabled, Then the unit is in Pascal
+
+### Stream sensor data
+#### Stream sensor data in forced mode
+
+``` c
+int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev)
+{
+ int8_t rslt;
+ uint8_t settings_sel;
+ struct bme280_data comp_data;
+
+ /* Recommended mode of operation: Indoor navigation */
+ dev->settings.osr_h = BME280_OVERSAMPLING_1X;
+ dev->settings.osr_p = BME280_OVERSAMPLING_16X;
+ dev->settings.osr_t = BME280_OVERSAMPLING_2X;
+ dev->settings.filter = BME280_FILTER_COEFF_16;
+
+ settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;
+
+ rslt = bme280_set_sensor_settings(settings_sel, dev);
+
+ printf("Temperature, Pressure, Humidity\r\n");
+ /* Continuously stream sensor data */
+ while (1) {
+ rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
+ /* Wait for the measurement to complete and print data @25Hz */
+ dev->delay_ms(40);
+ rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
+ print_sensor_data(&comp_data);
+ }
+ return rslt;
+}
+
+void print_sensor_data(struct bme280_data *comp_data)
+{
+#ifdef BME280_FLOAT_ENABLE
+ printf("%0.2f, %0.2f, %0.2f\r\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#else
+ printf("%ld, %ld, %ld\r\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#endif
+}
+```
+##### Stream sensor data in normal mode
+``` c
+int8_t stream_sensor_data_normal_mode(struct bme280_dev *dev)
+{
+ int8_t rslt;
+ uint8_t settings_sel;
+ struct bme280_data comp_data;
+
+ /* Recommended mode of operation: Indoor navigation */
+ dev->settings.osr_h = BME280_OVERSAMPLING_1X;
+ dev->settings.osr_p = BME280_OVERSAMPLING_16X;
+ dev->settings.osr_t = BME280_OVERSAMPLING_2X;
+ dev->settings.filter = BME280_FILTER_COEFF_16;
+ dev->settings.standby_time = BME280_STANDBY_TIME_62_5_MS;
+
+ settings_sel = BME280_OSR_PRESS_SEL;
+ settings_sel |= BME280_OSR_TEMP_SEL;
+ settings_sel |= BME280_OSR_HUM_SEL;
+ settings_sel |= BME280_STANDBY_SEL;
+ settings_sel |= BME280_FILTER_SEL;
+ rslt = bme280_set_sensor_settings(settings_sel, dev);
+ rslt = bme280_set_sensor_mode(BME280_NORMAL_MODE, dev);
+
+ printf("Temperature, Pressure, Humidity\r\n");
+ while (1) {
+ /* Delay while the sensor completes a measurement */
+ dev->delay_ms(70);
+ rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
+ print_sensor_data(&comp_data);
+ }
+
+ return rslt;
+}
+
+void print_sensor_data(struct bme280_data *comp_data)
+{
+#ifdef BME280_FLOAT_ENABLE
+ printf("%0.2f, %0.2f, %0.2f\r\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#else
+ printf("%ld, %ld, %ld\r\n",comp_data->temperature, comp_data->pressure, comp_data->humidity);
+#endif
+}
+```
+
+### Templates for function pointers
+``` c
+
+void user_delay_ms(uint32_t period)
+{
+ /*
+ * Return control or wait,
+ * for a period amount of milliseconds
+ */
+}
+
+int8_t user_spi_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
+{
+ int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
+
+ /*
+ * The parameter dev_id can be used as a variable to select which Chip Select pin has
+ * to be set low to activate the relevant device on the SPI bus
+ */
+
+ /*
+ * Data on the bus should be like
+ * |----------------+---------------------+-------------|
+ * | MOSI | MISO | Chip Select |
+ * |----------------+---------------------|-------------|
+ * | (don't care) | (don't care) | HIGH |
+ * | (reg_addr) | (don't care) | LOW |
+ * | (don't care) | (reg_data[0]) | LOW |
+ * | (....) | (....) | LOW |
+ * | (don't care) | (reg_data[len - 1]) | LOW |
+ * | (don't care) | (don't care) | HIGH |
+ * |----------------+---------------------|-------------|
+ */
+
+ return rslt;
+}
+
+int8_t user_spi_write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
+{
+ int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
+
+ /*
+ * The parameter dev_id can be used as a variable to select which Chip Select pin has
+ * to be set low to activate the relevant device on the SPI bus
+ */
+
+ /*
+ * Data on the bus should be like
+ * |---------------------+--------------+-------------|
+ * | MOSI | MISO | Chip Select |
+ * |---------------------+--------------|-------------|
+ * | (don't care) | (don't care) | HIGH |
+ * | (reg_addr) | (don't care) | LOW |
+ * | (reg_data[0]) | (don't care) | LOW |
+ * | (....) | (....) | LOW |
+ * | (reg_data[len - 1]) | (don't care) | LOW |
+ * | (don't care) | (don't care) | HIGH |
+ * |---------------------+--------------|-------------|
+ */
+
+ return rslt;
+}
+
+int8_t user_i2c_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
+{
+ int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
+
+ /*
+ * The parameter dev_id can be used as a variable to store the I2C address of the device
+ */
+
+ /*
+ * Data on the bus should be like
+ * |------------+---------------------|
+ * | I2C action | Data |
+ * |------------+---------------------|
+ * | Start | - |
+ * | Write | (reg_addr) |
+ * | Stop | - |
+ * | Start | - |
+ * | Read | (reg_data[0]) |
+ * | Read | (....) |
+ * | Read | (reg_data[len - 1]) |
+ * | Stop | - |
+ * |------------+---------------------|
+ */
+
+ return rslt;
+}
+
+int8_t user_i2c_write(uint8_t dev_id, uint8_t reg_addr, uint8_t *reg_data, uint16_t len)
+{
+ int8_t rslt = 0; /* Return 0 for Success, non-zero for failure */
+
+ /*
+ * The parameter dev_id can be used as a variable to store the I2C address of the device
+ */
+
+ /*
+ * Data on the bus should be like
+ * |------------+----------------------|
+ * | I2C action | Data |
+ * |------------+----------------------|
+ * | Start | - |
+ * | Write | (reg_addr) |
+ * | Write | (reg_data[0]) |
+ * | Write | (reg_addr + 1) |
+ * | Write | (reg_data[1]) |
+ * | Write | (....) |
+ * | Write | (reg_addr + len - 1) |
+ * | Write | (reg_data[len - 1]) |
+ * | Stop | - |
+ * |------------+----------------------|
+ */
+
+ return rslt;
+}
+
+```
+
+## Copyright (C) 2016 - 2017 Bosch Sensortec GmbH
projects / BME280_driver / blobdiff