Overview of device structure in IoT

This post is a part of course From beginner to expert in IoT, so if you’re interested, more information you will find inside the link.


Each one device has many components, but mostly for us as developers or people who just want to use the device it doesn’t matter too much to know everything about one particular device. That’s why I limited this post only to using elements of devices that you will find in the web.



Accelerometer  mostly used in drones for flight stabilization, rotating machinery to detect and check vibrations or navigation systems. Very useful for monitoring fleet or using a smart pedometer.

Gyroscope  primarily used in navigation systems for measurement of the speed of rotation in 3 axis directions. Can be used in systems where the key is monitoring the orientation of an object.

Humidity  you will find this kind of sensors in systems such as air conditioning, meteorology stations, hospitals, museums or automotive.

Temperature  most common sensor, you will find it in agriculture, health industry or manufacturing process with temperature requirements.

Pressure  sensor useful in manufacturing or maintenance systems, such as heating systems

Magnetometer  an example of use is as a metal detector for finding objects, compass, anti-locking system or even heartbeat monitors.

Motion detection – we can distinguish three types of sensors:

– Passive Infrared(PIR)  which detects body heat and used in home security systems.

– Ultrasonic – measures the reflection of a moving object by tracking the speed of sound waves.

– Microwave – cover two previous and work as Ultrasonic, but are vulnerable to electrical interference.

Image  this sensor you will find in the automobile where cars monitor signs, roads and try to detect important information about places around the car. Working with a customer also supported by this sensor, such as by measuring the emotional satisfaction of customer or general data about the type of customers.

Level  mostly used in a place where measuring the level or amount of liquids are required, such as sea level or water reservoirs.

Smoke & Gas   such as smoke or gas detector, by combining with IoT offer faster detection of fire & gas accidents.

Chemical – good example is Smart City, with chemical sensors you can detect radioactive, chemical or explosive accidents.


Short-range wireless

Bluetooth – the standard allows to connect only 7 nodes, that’s why Bluetooth mesh network was introduced and extended this amount to 32 767 nodes. At this moment you will find this technology, mostly in-house environment, but with Bluetooth 5.0 and Bluetooth mesh network and extended to 200-400 m.

Light-Fidelity(Li-Fi) – a similar technology to Wi-Fi, but instead of using radio waves, used visible light to transfer data up to 224 Gb/s. This kind of network you will find in airplanes, hospitals or nuclear power plants because don’t cause electromagnetic interference.

Near-field communication(NFC) – create connection up to 20 cm, mostly found in smartphones, but can be used in smart cards.

Quick Response Code (QR code)  used within the image sensors to transfer data in real-time by just shortcode information about the product. Do you want to provide information about the product in real-time by scanning it? It’s your solution.

Radio-frequency identification(RFID) – is split up into two “things”, RFID tag and RFID reader. The tag is a small chip that you can place on the product, person, container or whatever you want to mark. The reader will scan for tags and look at which tags are in range. This kind of solution speed up inventories in the biggest outlets where the amount of products is enormous and doing that manually is too slow.

Wi-Fi / Wi-Fi Direct – a most common wireless network that connects different devices via a local network such as a router. The device is a server and client for other devices.

Z-Wave – “extension” of Wi-Fi, primarily used in the home to connect different devices due to lower power consumption than Wi-Fi.

ZigBee  you will find it in small projects due to low-cost, low-power and wireless mesh network approach. Can be found in the home or in healthcare solutions.


Medium-range wireless

HaLow  protocol, which extends range possibilities of Wi-Fi, can cover a one-kilometer radius.

LTE – mobile communication standard which replaced the 3rd generation of a cellular network (3G), also known as 4G.


Long-range wireless

Low-power wide-area networking(LPWAN the standard allows long-range, low-power connection, but with the low-range data rate, which is up to 50 kbit/s. Most know implementation is LoRa.

Very small aperture terminal(VAST)  satellite communication technology using small dish antennas to connect with satellites and send data further to other terminals.



Ethernet – most know the wired network that using twisted pair and fiber optic links to connect via cable devices.

Multimedia over Coax Alliance(MoCA a specification used in the home environment to share content over coaxial cable up to 2,5 Gbit/s


Other useful components

CPU – central unit to perform basic operations such as arithmetic, logic or control. This kind of part you will find in smartphones or PC. With it the greatest benefit will take “edge” devices. It’s kind of devices that aggregate information from other devices, process some operations on data, such as serialization or filtering useful data and then send this kind of results to the cloud. In other words, reduce memory and process cost in the cloud and respond time on devices that work in real-time and need to know any critical situations ad hoc.

Memory – raspberry pi is a good example, you can extend this device with memory, SD Card and hold on their operating system, such as the Windows 10 IoT Core.

GPS/GLONASS – navigation systems are useful when you want to remotely monitor your own devices, but you need a system that will allow you to send localization to systems such as the Internet.

GSM –  system to contact with the device over cellular networks, sometimes when you don’t have an internet connection you can send commands via SMS to interact or make a call with device and vice versa.



Hat – when you want to build desired devices sometimes our device don’t have sensors, a network connection that we want to. The hat is an extension that you can plug-in into devices and extends the functionality of the device. Most know are Arduino and Rasberry Pi that allows building your own device from scratch.

Adapter – sometimes can happen that one kind of devices doesn’t allow to plug-in hat due to wrong pins or different architecture. I’m using Bit:2:Pi adapter to connect GSM/GPRS/GNSS hat with Micro: Bit’s device called AZ3166. This allows me to connect two different devices in a compact way.

Breadboard – the most common solution for everyone who wants to prototype your own device from scratch. Only one problem with this approach is the fact that breadboard isn’t ready for real duties of working, you can build own prototype and if it works then build own devices for real purposes.

Piotr Czech

I am software developer, blogger, mentor, geek, startupper, team leader. I started writing code when I was about 15 years old, creating my first program in C++. I believe that everything can be fixed or changed, by just keep doing small steps each day.

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