Project description

Basic features of the considered greenhouse are (i) the automatic control of the greenhouse air temperature (through automatic door/window opening and fan and lamp control), (ii) control of the soil humidity through automatic watering of the plants and (iii) presentation of the greenhouse control system in a simple web-site or mobile phone application. Such automation of the greenhouse conditions requires a variety of sensor and actuators, all connected to a Raspberry Pi computer acting as a central controller, connecting the entire system together, collecting inputs, providing outputs as well as hosting the web-site/mobile application presentation.

Raspberry Pi automated greenhouse [source].

Greenhouse operation can possibly be powered with renewable energy through installation of a small sized photovoltaic panel and a rechargeable battery system connected to the Raspberry Pi.

Small-sized photovoltaic panel [source].

The Raspberry Pi automated greenhouse can be divided into different subsystems, namely:

  1. Temperature control system (consisted of an outside and inside temperature sensor, window, doors, fan and lamp),
  2. Humidity control system (consisted of a soil humidity sensor and a water pump),
  3. Small-scaled microgrid (consisted of a solar panel, battery storage, and power measurements),
  4. Data acquisition and control system (database, web or mobile presentation),
  5. Possible upgrades

Temperature control:

Greenhouse temperature presents one of the most important elements of greenhouse climate. The temperature control loop consists of:

  • Measurements of environment and greenhouse temperatures
  • Door and window opening/closing control
  • Fan control (heating or cooling – depending on the environment conditions)
  • Heating control
  • Manual and automatic control (setpoint)
Greenhouse fan and lamp example [source].

Humidity control:

Humidity of the soil is a key element for plant growth and should be taken with special consideration. The humidity control loop consists of:

  • Measurement of soil humidity
  • Water pump control
  • Water tank with contactless water level measurement, possible rainwater usage
  • Manual and automatic control (setpoint)
Greenhouse watering example [source].

“Microgrid management”:

Microgrid management system consists of:

  • Battery charging/discharging control
  • Prediction of power consumption and production
  • Power consumption efficiency
Rasberry Pi battery storage example [source].

Data aquisition and control system

Data acquisition and control system (SCADA) consist of two-way database for storing the sensor measurement values and sending the commands to the actuators. The visualisation of control system is planned to be realized as web or mobile application to open the possibility for remote control and monitoring of the system.

Possible upgrades of the basic greenhouse system

The basic greenhouse system can possibly be upgraded with the following systems:

  • Solar irradiation measurement (visual, UV, IR)
  • Air humidity control system
  • Air pressure control system
  • CO2 level inside the greenhouse control system
  • Controllable shading system
  • Soil fertility (soil ph level control) control system