Today I will talk about the Internet of Things and its parts as an ecosystem. I will start off with the basic concepts of observing and controlling the different parts, and then talk about different levels of the ecosystem as well as a few words on security.
At the core of any Internet of Things solution is the ability to observe and control the state of the environment. Observations could be on distinctions, like whether a lamp of machine is on or off, a door or valve is open or closed, a tank is full or empty, it’s light or dark, hot or cold, dry or humid, or any intermediate state between all of those end points (lamp 80% on, tank 50% full, etc). The observations could also be on things like a specific location, a flow rate, the current pressure, a heartbeat, a touch, etc. As important is that all of these things can also be manipulated or controlled, like the increase or decrease of power, flow rate, and temperature (e.g. by turning up the heat or cooling).
The things that observe or capture information about the environment are called sensors, and just as the name implies, they can be seen as digital senses. Things that manipulate or control the environment are called actuators, and they can be seen as digital fingers. Here you can see examples of a number of sensors and actuators (and as their components are already mounted on small circuit boards, to make them easier to use, they are called modules).
The sensors and actuators form the base of the Internet of Things ecosystem, and as you can see here, they can be connected to an MQTT broker (for more info about MQTT, please see my previous video called “Internet of Things – Why You Need MQTT”). There could also be a number of other things connected to the broker, like a physical panel that show the readings from the sensors and that can have buttons that send instructions to the actuators. It could also be web sites and mobile apps, or any other system that want to interact with the sensors and actuators. The arrows that point to the broker represent publications, and those that point away from the broker represent subscriptions.
In its simplest form, each connection is one-way, i.e. either a publication or a subscription. However, in many cases the ecosystem is more dynamic, and some connections go both ways, i.e. they both publish and subscribe to different topics. An example could be a humidity sensor in a greenhouse that is programmed to publish a warning if the humidity exceeds a predefined interval, and if the interval needs to be changed, the sensor could also subscribe to a topic where such changes can be published. Another example is a web site that is subscribing to the temperature from many sensors in a house, and that is calculating an average temperature for the whole house, then that average could also be published on the broker.
When several such ecosystems of sensors, actuators, and applications are combined, they form a larger ecosystem that includes a number of brokers. The principle is still the same as for the smaller ecosystems, but such distributed ecosystems can create very powerful solutions for the Internet of Things.
As the environment can be manipulated in most solutions for the Internet of Things, which could have very serious consequences if the control gets into the wrong hands, security must be taking very seriously. This is a huge topic, but I just want to mention that there are security solutions available. For example, most MQTT brokers (e.g. mosquitto) have support for things like authentication, authorization, and encryption, and therefore it’s not a big deal to make them as secure as most multichannel services, web sites, and mobile apps.
That was an overall description of the Internet of Things ecosystem and its different parts.