This controller was started as a hobby project to grow some fresh herbs for my kitchen. For now planned features are:
- Control channels
- Air pump control (running for 20 minutes every hour by default).
- Water pump control. To simplify things the pump runs for 1 minute every hour and to prevent spilling the pump is wired in series with a simple float switch which will allow it to run only if the water level is too low. Should the water/nutrient tank be empty, water pump would just work as an additional air pump.
- Grow light control. Grow lights will be switched on based on the luxmeter reading
- Heater control. Heating pad (the kind they use on car seats) is planned to be installed and will be switched on and off based on the nutrient liquid temperature.
- Sensors and other peripherial devices
- Nutrient temperature sensor(s): Waterproof DS18B20 probe(s).
- Ambient light sensor: BH1750 IIC sensor.
- Ambient temperature/humidity: DHT22, planned replacement with several of the AM23xx IIC sensors.
- RTC module: DS3201. Used to trigger pump ON/OFF commands and for general timekeeping (for future logger extension).
- External EEPROM: AT25C32 (on the RTC module). Will be used to store some settings?..
- Display: 2004 LCD on the IIC bus.
- Planned extensions
- SD card data logger (SPI interface).
- Addition of a wireless controller (ESP8266) and MQTT integration. Will need to devise some way to interface with the Arduino.
- pH measurement (possibly – depends on whether pH probe can be acquired for a reasonable sum).
- Adding an enclosure with a fan for moisture/temperature control.
First version of hardware/software (simplified – only two pumps, no sensors, no display/logger, etc.) deployed on April 12th 2017 for unattended test run of about 10 days.
The project is licensed under Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license