added BME280 library

Author: HendrikVE

libraries/BME280-2.3.0/LICENSE

@@ -0,0 +1,325 @@
+# BME280
+Provides an Arduino library for reading and interpreting Bosch BME280 data over I2C, SPI or Sw SPI. Additional environment calculation functions are provided. ESP and BRZO are now supported.
+
+## Table of Contents
+
+1. [BME280](#bme280)
+2. [Table of Contents](#table-of-contents)
+3. [Summary](#summary)
+4. [Installation](#installation)
+5. [Usage](#usage)
+6. [Enumerations](#enumerations)
+7. [Settings](#settings)
+      - [BME280I2C::Settings](#settings)
+      - [BME280Spi::Settings](#settings)
+      - [BME280SpiSw::Settings](#settings)
+8. [Methods](#methods)
+      - [BME280I2C(const BME280I2C::Settings& settings)](#methods)
+      - [BME280Spi(const BME280Spi::Settings& settings)](#methods)
+      - [BME280SpiSw(const BME280SpiSw::Settings& settings)](#methods)
+      - [bool  begin()](#methods)
+      - [void  setSettings(const Settings& settings)](#methods)
+      - [const Settings& getSettings() const](#methods)
+      - [float temp(TempUnit unit)](#methods)
+      - [float pres(PresUnit unit)](#methods)
+      - [float hum()](#methods)
+      - [void  read(float& pressure, float& temp, float& humidity, TempUnit tempUnit, PresUnit presUnit)](#methods)
+      - [ChipModel chipModel()](#methods)
+
+9. [Environment Calculations](#environment-calculations)
+      - [float Altitude(float pressure, bool metric = true, float seaLevelPressure = 101325)](#environment-calculations)
+      - [float EquivalentSeaLevelPressure(float altitude, float temp, float pres)](#environment-calculations)
+      - [float DewPoint(float temp, float hum, bool metric = true)](#environment-calculations)
+10. [Contributing](#contributing)
+11. [History](#history)
+12. [Credits](#credits)
+13. [License](#license)
+<snippet>
+<content>
+
+## Summary
+
+Reads temperature, humidity, and pressure. Calculates altitude and dew point. Provides functions for english and metric. Also reads pressure in Pa, hPa, inHg, atm, bar, torr, N/m^2 and psi.
+
+## Installation
+
+To use this library download the zip file, uncompress it to a folder named BME280. Move the folder to {Arduino Path}/libraries.
+
+## Usage
+
+Include the library at the top of your Arduino script. `#include <BME280>`
+Create a global or local variable. `BME280 bme`
+In your start up call `bme.begin()`.
+Read the temperature, humidity, pressure, altitude and/or dew point.
+
+`float pres, temp, hum`
+`bme.read(pres, temp, hum)`
+
+or
+
+`temp = bme.temp()`
+`hum = bme.hum()`
+`pres = bme.pres()`
+
+## Enumerations
+#### TempUnit Enum
+   * TempUnit_Celsius
+   * TempUnit_Fahrenheit
+
+#### PresUnit Enum
+   * PresUnit_Pa
+   * PresUnit_hPa
+   * PresUnit_inHg
+   * PresUnit_atm
+   * PresUnit_bar
+   * PresUnit_torr
+   * PresUnit_psi
+
+#### OSR Enum
+   * OSR_X1
+   * OSR_X2
+   * OSR_X4
+   * OSR_X8
+   * OSR_X16
+
+#### Mode Enum
+   * Mode_Sleep
+   * Mode_Forced
+   * Mode_Normal
+
+#### StandbyTime Enum
+   * StandbyTime_500us
+   * StandbyTime_62500us
+   * StandbyTime_125ms
+   * StandbyTime_250ms
+   * StandbyTime_50ms
+   * StandbyTime_1000ms
+   * StandbyTime_10ms
+   * StandbyTime_20ms
+
+#### Filter Enum
+   * Filter_Off
+   * Filter_1
+   * Filter_2
+   * Filter_4
+   * Filter_8
+   * Filter_16
+
+#### ChipModel Enum
+   * ChipModel_Unknown
+   * ChipModel_BME280
+   * ChipModel_BMP280
+
+## Settings
+
+#### BME280::Settings Struct
+```
+    * Temperature Oversampling Rate (tempOSR): OSR Enum, default = OSR_X1
+
+    * Humidity Oversampling Rate (humOSR): OSR Enum, default = OSR_X1
+
+    * Pressure Oversampling Rate (presOSR): OSR Enum, default = OSR_X1
+
+    * Mode (mode): Mode Enum, default = Mode_Forced
+
+    * Standby Time (standbyTime): StandbyTime Enum, default = StandbyTime_1000ms
+
+    * Filter (filter): Filter Enum, default = Filter_Off
+
+    * SPI Enable: SpiEnable Enum, default = false
+      values: true = enable, false = disable
+```
+
+#### BME280I2C::Settings Struct
+
+   * Includes all fields in BME280 settings.
+```
+   * BME 280 Address (bme280Addr): uint8_t, default = 0x76
+```
+#### BME280Spi::Settings Struct
+
+   * Includes all fields in BME280 settings.
+```
+   * SPI Chip Select Pin (spiCsPin): uint8_t
+      values: Any pin 0-31
+```
+
+#### BME280Spi::Settings Struct
+   * Includes all fields in BME280 settings.
+```
+   * SPI Chip Select Pin (spiCsPin): uint8_t
+     values: Any pin 0-31
+
+   * SPI Master Out Slave In Pin (spiMosiPin): uint8_t
+     values: Any pin 0-31
+
+   * SPI Master In Slave Out Pin (spiMisoPin): uint8_t
+     values: Any pin 0-31
+
+   * SPI Serial Clock Pin (spiSckPin): uint8_t
+     values: Any pin 0-31
+```
+## Methods
+
+
+#### BME280I2C(const BME280I2C::Settings& settings)
+
+  Constructor used to create the I2C Bme class. All parameters have default values.
+
+#### BME280Spi(const BME280Spi::Settings& settings)
+
+  Constructor used to create the Spi Bme class. All parameters have default values except chip select.
+
+#### BME280SpiSw(const BME280SpiSw::Settings& settings)
+
+  Constructor used to create the software Spi Bme class. All parameters have default values except chip select, mosi, miso and sck.
+
+#### bool  begin()
+
+  Method used at start up to initialize the class. Starts the I2C or SPI interface. Can be called again to re-initialize the mode settings.
+ ```
+   * return: bool, true = success, false = failure (no device found)
+ ```
+
+#### void setSettings(const Settings& settings)
+
+  Method to set the sensor settings.
+
+
+#### const Settings& getSettings() const
+
+  Method to get the sensor settings.
+
+#### float temp(TempUnit unit)
+
+  Read the temperature from the BME280 and return a float.
+```
+    return: float = temperature
+
+    * unit: tempUnit, default = TempUnit_Celsius
+```
+
+#### float pres(PresUnit unit)
+
+  Read the pressure from the BME280 and return a float with the specified unit.
+```
+    return: float = pressure
+
+    * unit: uint8_t, default = PresUnit_Pa
+```
+
+#### float hum()
+
+  Read the humidity from the BME280 and return a percentage as a float.
+```
+    * return: float = percent relative humidity
+```
+#### void  read(float& pressure, float& temp, float& humidity, TempUnit tempUnit, PresUnit presUnit)
+
+  Read the data from the BME280 with the specified units.
+```
+    return: None, however, pressure, temp and humidity are changed.
+
+    * Pressure: float, reference
+      values: reference to storage float for pressure
+
+    * Temperature: float, reference
+      values: reference to storage float for temperature
+
+    * Humidity: float, reference
+      values: reference to storage float for humidity
+
+    * tempUnit: tempUnit, default = TempUnit_Celsius
+
+    * presUnit: uint8_t, default = PresUnit_Pa
+```
+
+#### ChipModel chipModel()
+```
+    * return: [ChipModel](#chipmodel-enum) enum
+```
+
+## Environment Calculations
+
+#### float Altitude(float pressure, bool metric = true, float seaLevelPressure = 101325)
+
+  Calculate the altitude based on the pressure with the specified units.
+  Return: float = altitude
+```
+    * Pressure: float, unit = Pa
+      values: any float
+
+    * Metric: bool, default = true
+      values: true = meters, false = feet
+
+    * Sea Level Pressure: float, unit = Pa, default = 101325
+      values:  any float
+```
+
+#### float EquivalentSeaLevelPressure(float altitude, float temp, float pres)
+
+  Convert current pressure to equivalent sea-level pressure.
+
+```
+    return: The equivalent pressure at sea level.
+
+    * altitude: float
+      values: meters
+
+    * temp: float
+      values: celsius
+
+    * pres: float
+      values: unit independent
+```
+
+#### float DewPoint(float temp, float hum, bool metric = true)
+
+  Calculate the dew point based on the temperature and humidity with the specified units.
+```
+    return: float = dew point
+
+    * Temperature: float, unit = Celsius if metric is true, Fahrenheit if metric is false
+      values: any float
+
+    * Humidity: float, unit = % relative humidity
+      values: any float
+
+    * Metric: bool, default = true
+      values: true = return degrees Celsius, false = return degrees Fahrenheit
+```
+
+
+## Contributing
+
+1. Fork the project.
+2. Create your feature branch: `git checkout -b my-new-feature`
+3. Commit your changes: `git commit -am 'Add some feature'`
+4. Push to the branch: `git push origin my-new-feature`
+5. Submit a pull request.
+
+## History
+
+- Jan  1, 2016   - Version 1.0.0 released
+- Sep  19, 2016  - Version 2.0.0 released (Restructure for I2C and SPI)
+- Nov 21,  2016  - Version 2.0.1 released (Set mode support)
+- Dec  19, 2016  - Version 2.1.0 released (Support for SPI)
+- Dec  21, 2016  - Version 2.1.1 released (Bugs)
+- Feb  17, 2017  - Version 2.1.2 released (Docs)
+- Sept  9, 2017  - Version 2.1.3 released (Formatting, reorg)
+- Sept 13, 2017  - Version 2.1.4 released (Examples update, bug fixes)
+- Oct   7, 2017  - Version 2.2.0 released (Enums, begin restructure)
+- Oct  10, 2017  - Version 2.2.1 released (Bug fixes)
+- Nov  21, 2017  - Version 2.3.0 released (Examples updates, env calc fixes, bugs)
+
+## Credits
+
+Written by Tyler Glenn, 2016.
+
+Special thanks to Mike Glenn for editing and reviewing the code.
+
+## License
+
+GNU GPL, see License.txt
+</content>
+</snippet>