home-assistant.github.io/source/_components/sensor.bme280.markdown

layout	title	description	date	sidebar	comments	sharing	footer	logo	ha_category	ha_release	ha_iot_class
page	BME280 Sensor	Instructions how to integrate a BME280 sensor in a Raspberry PI into Home Assistant.	2017-06-10 00:00	true	false	true	true	raspberry-pi.png	Sensor	0.47	Local Push

The bme280 sensor platform allows you to read temperature, humidity and pressure values of a Bosch BME280 Environmental sensor connected via I2c bus (SDA, SCL pins) to your Raspberry Pi. 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:

# 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:

# 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

# 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

# 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:

# 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:

# 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:

/usr/sbin/i2cdetect -y 1

It will output a table like this:

     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).