solarlog2mqtt - A Solar Log to MQTT Bridge allowing unidirectional data transfer

I've created this project to read data from Solar Log devices and publish it to MQTT. This works well for integrating Solar Log data into home automation systems like HomeAssistant.

It is quite simple and does what it's name says: It works as a bridge between Solar Log and MQTT translating data from Solar Log to MQTT messages.

Installation

Native installation with Python venv

Requires Python 3.12.

Philosophy is to install it under /usr/local/lib/solarlog2mqtt and control it via systemd.

cd /usr/local/lib
git clone https://c0d3.sh/andre/solarlog2mqtt.git
cd solarlog2mqtt
./install

The install script uses uv to provision a local virtual environment and install the dependencies declared in pyproject.toml. It attempts an editable install so the solarlog2mqtt console command works immediately; if build dependencies are unavailable (e.g., offline installs), the run script still loads the package directly from src/.

Configuration

The configuration is located in /etc/solarlog2mqtt.conf.

Each configuration option is also available as command line argument.

• copy solarlog2mqtt.conf.example
• configure as you like

option	default	arguments	comment
mqtt_host	'localhost'	-m, --mqtt_host	The hostname of the MQTT server.
mqtt_port	1883	--mqtt_port	The port of the MQTT server.
mqtt_keepalive	30	--mqtt_keepalive	The keep alive interval for the MQTT server connection in seconds.
mqtt_clientid	'solarlog2mqtt'	--mqtt_clientid	The clientid to send to the MQTT server.
mqtt_user	-	-u, --mqtt_user	The username for the MQTT server connection.
mqtt_password	-	-p, --mqtt_password	The password for the MQTT server connection.
mqtt_topic	'solarlog'	-t, --mqtt_topic	The topic to publish MQTT message.
mqtt_tls	-	--mqtt_tls	Use SSL/TLS encryption for MQTT connection.
mqtt_tls_version	'TLSv1.2'	--mqtt_tls_version	The TLS version to use for MQTT. One of TLSv1, TLSv1.1, TLSv1.2.
mqtt_verify_mode	'CERT_REQUIRED'	--mqtt_verify_mode	The SSL certificate verification mode. One of CERT_NONE, CERT_OPTIONAL, CERT_REQUIRED.
mqtt_ssl_ca_path	-	--mqtt_ssl_ca_path	The SSL certificate authority file to verify the MQTT server.
mqtt_tls_no_verify	-	--mqtt_tls_no_verify	Do not verify SSL/TLS constraints like hostname.
solarlog_host	'192.168.1.100'	-s, --solarlog_host	The address of the Solar Log device.
solarlog_port	80	--solarlog_port	The port of the Solar Log device.
solarlog_user	-	--solarlog_user	The username for the Solar Log device connection.
solarlog_password	-	--solarlog_password	The password for the Solar Log device connection.
poll_interval_periodic	300	--poll_interval_periodic	The polling interval for periodic data in seconds.
poll_interval_current	30	--poll_interval_current	The fast polling interval for current data in seconds.
historic_data	-	--historic_data	Enable historic data collection.
inverter_import	true	--inverter_import/--no_inverter_import	Enable individual inverter import.
health_check_interval	0	--health_check_interval	Health check interval in seconds (0 disables).
restart_delay	90	--restart_delay	Delay before restart after critical failure.
forecast_enabled	-	--forecast_enabled	Enable external forecast.solar API integration.
forecast_latitude	-	--forecast_latitude	Latitude for forecast.solar API.
forecast_longitude	-	--forecast_longitude	Longitude for forecast.solar API.
forecast_declination	30	--forecast_declination	Panel tilt in degrees.
forecast_azimuth	180	--forecast_azimuth	Panel azimuth in degrees (180=south).
timestamp	-	-z, --timestamp	Publish timestamps for all topics, e.g. for monitoring purposes.
verbose	-	-v, --verbose	Be verbose while running (forces DEBUG).
log_level	INFO	--log-level	Logging level: CRITICAL, ERROR, WARNING, INFO, DEBUG, NOTSET.
log_format	text	--log-format	Logging format: text or json.
-	'/etc/solarlog2mqtt.conf'	-c, --config	The path to the config file.

Solar Log

Currently, only HTTP access to Solar Log devices is supported. It may become more in the future, if I found testing environments with different setups. Feel free to add other connection types and open a pull request for this.

Data Points

The bridge automatically discovers and publishes available data from your Solar Log device.

The default operating mode is to read from the Solar Log device and publish the values to MQTT.

Publishing

All values are published using a hierarchical topic structure and the MQTT topic.

So, the current production is published to solarlog/status/pac and consumption to solarlog/status/consumption.

Running solarlog2mqtt

Use the provided run script or invoke via the venv:

./run -c solarlog2mqtt.conf
# or
./venv/bin/python -m solarlog2mqtt -c solarlog2mqtt.conf --log-level INFO
# or
./venv/bin/solarlog2mqtt -c solarlog2mqtt.conf --log-level INFO

For service management, use systemd or your preferred supervisor.

Support

I have not the time (yet) to provide professional support for this project. But feel free to submit issues and PRs, I'll check for it and honor your contributions.

Acknowledgments

• Inspired by Gerrit's (c0d3.sh|GitHub) smarthome repositories

License

The whole project is licensed under BSD-3-Clause license. Stay fair.