Introduction
As a continuation of the Air-conditioning system post, in today´s newsletter Opiron suggests expanding the HVAC system controlled through the Touchberry Pi Panel PC and Ardbox Relay from Industrial Shields. As the last post, the suggested SCADA that will run on the Touchberry Pi is the following: myscadatechnologies.com Panel Pc
Summarizing the previous post, we designed a system that was able to activate the air conditioning with a relay. In order to expand the system, we will include the following sensors to have a complete automatic HVAC system:
- Inside temperature.
- Outside temperature.
- PID development in order to control the inside temperature (the relay will be controlled by the PID loop).
Additionally, the air conditioning system will be integrated into a complete home automation solution where the Scada will give us access to light system control, open and close windows, and security cameras.
Software and code: Inputs and outputs definition
What are inputs and outputs from the coding point of view? As inputs, we will consider the inside and outside temperature. As output, the relay activates the air conditioning that we already programmed in the last post. As mentioned in the last post, the SCADA is owned by myscadatechnologies.com. Its main advantages are that is Open Source based, and very easy to be used. We will use I2C to communicate the SCADA and the Ardbox PLC.
The code to be uploaded is the next one:
2014111_arduino_code
SCADA design: Control Screen
SCADA design: Control Screen
Once we have already defined PLC programming, it is time to define the screen we will make the interaction between man and machine (HMI). Designing SCADAs really forces us to simplify and decide what’s most important- what needs to stay on the screen. As we want to implement an easy to use temperature control screen, we will show a thermometer with the actual temperature inside, and 4 big windows to see the basic features of the system. The first window with the temperatures inside and outside, at right, the system status window to have an easy access to alarms and other parameters, and below the temperature PID´s, one for the day and the other one for the night. At the left of the screen we will have a menu to access to the other parts of the system (lighting, temperatures, windows, cameras and service).
Key Benefits
The main benefits of this suggested solution are:
Automatic temperature regulation:
The relay is now controlled by the PID!
Scalable system:
The purposed system permits to the connection of multiple devices to the Touchberry Pi.
Open Source base:This feature means big flexibility, big availability of resources on the internet in case of failures or change implementations, etc.
Control climate conditions through an HMI panel.