bh1750-control

About

The control utility and daemon require a bh1750 sensor connected to the i2c bus and this kernel driver: https://gitlab.com/alexandermishin13/bh1750-kmod.

An idea of this tool is plain:

• There is one or more rows of defined pairs: (lighting level -> action);
• Each row of levels has its own scope;
• After measuring the ambient light level, the action with the highest reached level value for each scope is performed.

Prerequstives

For run bh1750-control You need to install following Python modules:

sudo pkg install py37-sqlite3
sudo pkg install py37-sysctl

The SQLite library must also be compiled with neither SQLITE_OMIT_FOREIGN_KEY nor SQLITE_OMIT_TRIGGER.

Installation and run

All You need to install:

make
sudo make install

If You want to control the bh1750 sensor by daemon You may need to add following lines to /etc/rc.conf:

bh1750_daemon_enable="YES"
bh1750_daemon_number="0" # Sensor number in sysctl.
bh1750_daemon_dbfile="/var/db/bh1750/actions.sqlite"
bh1750_daemon_pidfile="/var/db/bh1750-daemon.pid"

...or use a profile based configuration for multiple sensors. (See rc.conf.d/bh1750_daemon for example. You can copy it along with the folder to /usr/local/etc/ instead of use /etc/rc.conf and change it for your needs).

Now You can run the service[-s] by:

sudo service bh1750-daemon start

The above values are hardcoded in the daemon service script as defaults. If you omit lines with them, they will still be used.

Usage

DB control utility

The tool bh1750-control allows you to perform the following actions with the database:

• add an action for the level in the scope;
• delete an action for the level in the scope or the whole scope;
• list all defined actions;
• run for measure light, compute levels and execute actions. You can run it by cron at most once a minute.

Service

Or You can use a service bh1750-daemon for run the actions. The daemon reads the /dev/bh1750/<n> character device for measured light level, searches the database for commands and runs it. With the daemon You may set delays for commands. During the delay, the command can be automatically canceled if the illumination changes significantly, or executed after the delay has expired.

Status

Still in development but works fine for me. I use it mainly to adjust the brightness of the tm1637 display depending on the ambient light: https://gitlab.com/alexandermishin13/tm1637-kmod