BH1750 Light sensor
The bh1750 sensor platform allows you to read the ambient light level in Lux from a BH1750FVI sensor connected via I2c bus (SDA, SCL pins). It allows you to use all the resolution modes of the sensor described in its datasheet.
Tested devices:
Configuration
To use your BH1750 sensor in your installation, add the following to your configuration.yaml file:
# Example configuration.yaml entry
sensor:
- platform: bh1750
Configuration Variables
- name
-
(string)(Optional)
Name of the sensor.
Default value:
BH1750 Light Sensor
- i2c_address
-
(string)(Optional)
I2c address of the sensor. It is 0x23 or 0x5C.
Default value:
35
- i2c_bus
-
(integer)(Optional)
I2c bus where the sensor is.
Default value:
1, for Raspberry Pi 2 and 3.
- operation_mode
-
(string)(Optional)
Working mode for the sensor.
Default value:
continuous_high_res_mode_1
- sensitivity
-
(integer)(Optional)
The sensitivity of the sensor can be a value between 31 and 254.
Default value:
69
- measurement_delay_ms
-
(integer)(Optional)
Delay time in ms for waiting the sensor to get the measure.
Default value:
120
- multiplier
-
(integer)(Optional)
Correction coefficient to multiply the measured light level. Value between 0.1 and 10.
Default value:
1
Full Examples
If you want to specify the resolution mode of the digital sensor or need to change the default I2c address (which is 0x23), add more details to the configuration.yaml file.
The sensor can work with resolutions of 0.5 lx (high res mode 1), 1 lx (high res mode 2) or 4 lx (low res mode), and make measurements continuously or one time each call. To set any of these operation modes, select one of these combinations: continuous_low_res_mode, continuous_high_res_mode_2, continuous_high_res_mode_1, one_time_high_res_mode_1, one_time_high_res_mode_2, one_time_low_res_mode.
# Example of customized configuration.yaml entry
sensor:
- platform: bh1750
name: Ambient light
i2c_address: 0x5C
operation_mode: one_time_high_res_mode_1
sensitivity: 60
measurement_delay_ms: 200
scan_interval: 25
Directions for installing smbus support on Raspberry Pi
Enable I2c interface with the Raspberry Pi configuration 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 0x23 (there are more i2c sensors in that Raspberry Pi).