BME280 Driver

For Doxygen documentation click <a href="https://juraszekl.github.io/BME280_Driver/index.html" >here</a>. (only latest version)

Offline doxygen documentation for current version is attached as Doc.zip file. Unzip this file and open index.html in your browser.

Driver for Bosch BME280 Combined sensor.

This version contains abstract layer only - user must develop platform-specific driver (just three functions are needed).

Features

• Communication with I2C and SPI bus
• Read all measured values in Normal and Forced mode
• Results returned as integers or floats
• Configurable use 32-bit variables only (when 64-bit are not avalible)
• No dynamic memory allocation used
• Multithread use not supported yet

Driver is still under development, next features will be add soon. Current version - v2.0.x

Sensor description

The BME280 is a humidity sensor especially developed for mobile applications and wearables where size and low power consumption are key design parameters. The unit combines high linearity and high accuracy sensors and is perfectly feasible for low current consumption, long-term stability and high EMC robustness. The humidity sensor offers an extremely fast response time and therefore supports performance requirements for emerging applications such as context awareness, and high accuracy over a wide temperature range. BME280 Datasheet

Motivation

This project is for learning purposes only. Feel free to use it.

How to use

To use this driver perform steps listed below:

1. Clone driver into your workign directory:

git clone https://github.com/JuraszekL/BME280_Driver.git

or use as submodule if your working directory is a git repo

git submodule add https://github.com/JuraszekL/BME280_Driver.git

2. Include **__bme280.h__** file:

#include "bme280.h"

3. Perform configuration in **__bme280.h__** file if needed:

 
#define USE_64BIT
#define USE_FLOATS_RESULTS
#define USE_INTEGER_RESULTS
#define USE_GETTERS
#define USE_SETTERS
#define USE_NORMAL_MODE
#define USE_FORCED_MODE

4. Create global BME280_Driver_t structure and fill it with platform specific data:

 
typedef struct {
 
    bme280_readregisters read;
    bme280_writeregister write;
    bme280_delayms delay;
    void *env_spec_data;
    uint8_t i2c_address;
 
} BME280_Driver_t;
 

5. Write platform-specific functions required by driver:

Read Function:

 
typedef int8_t (*bme280_readregisters)(uint8_t reg_addr, uint8_t *rxbuff, uint8_t rxlen, void *driver);

Write Function:

 
typedef int8_t (*bme280_writeregister)(uint8_t reg_addr, uint8_t value, void *driver);

Delay Function:

 
typedef void (*bme280_delayms)(uint8_t delay_time);

6. Use BME280_Init Function before any operation:

BME280_t *Dev structure is a reference for single sensor you want to work with. Should be global as well. Use pointer to this structure with any other functions from this driver.

 
int8_t BME280_Init(BME280_t *Dev, BME280_Driver_t *Driver);

Optional steps

• Change defined types if needed:

  typedef int32_t BME280_S32_t;   
  typedef uint32_t BME280_U32_t;  
  typedef int64_t BME280_S64_t;   

• Set all sensor's settings at once (after Init function)

   
  int8_t BME280_ConfigureAll(BME280_t *Dev, BME280_Config_t *Config);