Control application
The main control application of Aquarium control implements the following features:
- Data acquisition of water temperature, pH and conductivity
- Data acquisition of ambient temperature and humidity
- Refill control for fresh water
- Feed control
- Water temperature control using air ventilation and heater
- Balling mineral dosing
The control of the relays for operating the devices can use two different modes:
- Using an Arduino-based relay actuation
- Using the GPIO of the Raspberry Pi (requires additional hardware)
Additionally, the main control application implements the following supporting features:
- Version comparison between database and application
- Configuration using a Rust .toml configuration file
- Logging
- Command interface to receive instructions from outside of the application via a POSIX message queue
- Storage of recorded data in SQL database
- File-based communication to RAM-disk
- Usage of simulator to run with simulated sensor data for development purposes
- Schedule checks to limit the hour of day of operating certain actuators
- Communication with HW Watchdog
The application is written in Rust and is automatically started using systemd.
The documentation of the software is available here.
Development for the main control application requires the setup of the development environment.
There is a release procedure which is highly recommended to be followed also by anyone developing the SW further.
Architecture
The application spawns the following threads:
| Thread name | Purpose |
|---|---|
| signal_handler | Receiving signals from the operating system |
| schedule_check | Polling the database to capture changes of the actuator channel. Informing other threads about it. |
| sensor_manager | Data acquisition |
| relay_manager | Actuation of relays |
| data_logger | Recording of data |
| tank_level_switch | Postprocessing of tank level switch position signal |
| refill | Fresh water refill control |
| heating | Heating control |
| ventilation | Ventilation control |
| balling | Balling mineral dosing control |
| watchdog | Sending alive signal to Raspberry Pi hardware watchdog |
| monitors | Diagnostics (not implemented as of January, 2026) |
| messaging | Receiving communication via message queue |
| memory | Monitoring memory utilization |
| ds18b20 | Recording data from DS18B20 temperature sensor |
| feed | Feed control |
| i2c_interface | Communication via I2C |
| atlas_scientific | Recording data from Atlas Scientific temperature sensor |
| dht | Recording data from DHT sensor |
| publish_pid | Writing PID to lock file |