add BME280 sensor platform doc

source/_components/sensor.bme280.markdown

@@ -0,0 +1,143 @@
+---
+layout: page
+title: "BME280 Sensor"
+description: "Instructions how to integrate a BME280 sensor in a Raspberry PI into Home Assistant."
+date: 2017-06-10 00:00
+sidebar: true
+comments: false
+sharing: true
+footer: true
+logo: raspberry-pi.png
+ha_category: Sensor
+ha_release: 0.47
+ha_iot_class: "Local Push"
+---
+
+
+The `bme280` sensor platform allows you to read temperature, humidity and pressure values of a [Bosch BME280 Environmental sensor](https://cdn-shop.adafruit.com/datasheets/BST-BME280_DS001-10.pdf) connected via [I2c](https://en.wikipedia.org/wiki/I²C) bus (SDA, SCL pins) to your [Raspberry Pi](https://www.raspberrypi.org/). It allows you to use all the operation modes of the sensor described in its datasheet.
+
+To use your BME280 sensor in your installation, add the following to your `configuration.yaml` file:
+
+```yaml
+# Example configuration.yaml entry
+sensor:
+  - platform: bme280
+```
+
+Or, if you want to specify the working mode of the digital sensor or need to change the default I2c address (which is 0x76), add more details to the yaml config:
+
+```yaml
+# Example of customized configuration.yaml entry
+sensor:
+  - platform: bme280
+    name: Ambient
+    i2c_address: 0x77
+    operation_mode: 2  # forced mode
+    time_standby: 5
+    oversampling_temperature: 4
+    oversampling_pressure: 4
+    oversampling_humidity: 4
+    delta_temperature: -0.5
+    monitored_conditions:
+      - temperature
+      - humidity
+      - pressure
+    scan_interval: 40
+```
+
+This sensor is somehow famous for generating relatively high temperature measurements compared to other sensors (it looks like self-heating does not feel good for some encapsulations). If you experience this problem, you can define an absolute delta of temperature correction using a negative number.
+
+Configuration variables:
+
+- **name** (*Optional*): The name of the sensor
+- **i2c_address** (*Optional*): I2c address of the sensor. It is 0x76 or 0x77.
+- **i2c_bus** (*Optional*): I2c bus where the sensor is. Defaults to 1, for Raspberry Pi 2 and 3.
+- **operation_mode** (*Optional*): Power mode for the sensor. Use 2 for forced mode or 3 for normal mode. Defaults to normal mode.
+- **time_standby** (*Optional*): Standby time in ms for normal mode of operation as described in the sensor datasheet. Defaults to 5 ms.
+- **oversampling_temperature** (*Optional*): Oversampling multiplier as described in the sensor datasheet. Can be 0 (no sampling), 1, 2, 4, 8, or 16. Default is 1.
+- **oversampling_pressure** (*Optional*): Oversampling multiplier as described in the sensor datasheet. Can be 0 (no sampling), 1, 2, 4, 8, or 16. Default is 1.
+- **oversampling_humidity** (*Optional*): Oversampling multiplier as described in the sensor datasheet. Can be 0 (no sampling), 1, 2, 4, 8, or 16. Default is 1.
+- **filter_mode** (*Optional*): IIR filter coeficient as described in the sensor datasheet. Default is 0, for filter off.
+- **delta_temperature** (*Optional*): Absolute delta for temperature correction.
+- **monitored_conditions** array  (*Optional*): Conditions to monitor. Available conditions are *temperature*, *humidity* and *pressure*. By default all three are displayed.
+
+#### Customizing the sensor data
+
+**Give the values friendly names & icons**
+
+Add the following to your `customize`
+
+```yaml
+# Example configuration.yaml entry
+customize:
+  sensor.ambient_temperature:
+    icon: mdi:thermometer
+    friendly_name: "Temperature"
+  sensor.ambient_humidity:
+    icon: mdi:weather-rainy
+    friendly_name: "Humidity"
+  sensor.ambient_pressure:
+    icon: mdi:gauge
+    friendly_name: "Pressure"
+```
+
+**Create a group**
+
+Add the following to your `groups`
+
+```yaml
+# Example configuration.yaml entry
+group:
+  ambient_sensor:
+    name: BME280 Environment sensor
+    entities:
+      - sensor.ambient_temperature
+      - sensor.ambient_humidity
+      - sensor.ambient_pressure
+```
+
+
+### Directions for installing smbus support on Raspberry Pi:
+
+Enable I2c interface with the Raspberry Pi config utility:
+```bash
+# pi user environment: Enable i2c interface
+sudo raspi-config
+```
+Select `Interfacing options->I2C` choose `<Yes>` and hit `Enter`, then go to `Finish` and you'll be prompted to reboot.
+
+Install dependencies for use the `smbus-cffi` module and enable your _homeassistant_ user to join the _i2c_ group:
+```bash
+# pi user environment: Install i2c dependencies and utilities
+sudo apt-get install build-essential libi2c-dev i2c-tools python-dev libffi-dev
+
+# pi user environment: Add homeassistant user to the i2c group
+sudo addgroup homeassistant i2c
+
+# pi user environment: Reboot Raspberry Pi to apply changes
+sudo reboot
+```
+
+###### Check the i2c address of the sensor
+
+After installing `i2c-tools`, a new utility is available to scan the addresses of the connected sensors:
+
+```bash
+/usr/sbin/i2cdetect -y 1
+```
+
+It will output a table like this:
+
+```text
+     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
+00:          -- -- -- -- -- -- -- -- -- -- -- -- --
+10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+20: -- -- -- 23 -- -- -- -- -- -- -- -- -- -- -- --
+30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+40: 40 -- -- -- -- -- UU -- -- -- -- -- -- -- -- --
+50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
+70: -- -- -- -- -- -- -- 77
+```
+
+So you can see the sensor address what you are looking for is **0x77** (there are more i2c sensors in that Raspberry Pi).