Anatomy of an IoT device

By: Segiy Sergienko, 4 Jan 2017
3 minutes

Reading Time: 3 minutes

Today the IoT market is growing rapidly and the idea of digital future makes it very attractive for users and clients, as well as for new players on the market.

Energy storage module

Li–Ion Battery AAA/AA Batteries Energy Harvester

RF module

Sensor module

Bluetooth Cellular (GSM, CDMA, LTE) LoRaWAN
Z-Wave ZigBee 6LoWPAN
Wi–Fi NFC-Near Field Communication SigFox
Thread MiWi WirelessHART
ISA100.11a EnOcean

Sensor module

Humidity Sensors Light Sensors Magnetometers
Micro Flow Sensors Position & Angle Sensors Proximity/ Presence Sensors
Speed Sensors Acoustic & Vibration Sensors Auto & Transportation Sensors
Displacement Sensors Distance Sensors Force Sensors
Gas RFID Sensors Heat & Thermal Sensors

Each IoT solution represents a whole ecosystem and includes a wide range of functional elements such as data collectors, means of data storage, processing and visualization and action actuators.

None of these elements are mandatory and some may be excluded, while new ones may be introduced.

These elements can be divided into two groups:

  • collectors and actuators, so called embedded devices, computers or IoT devices;
  • dedicated servers that tackle raw data and provide useful feedback to users or to devices.

Let’s put aside the cloud and consider the main aspects of different embedded devices that should be taken into account on the design stage.

Foregoing devices collect data and eventually send it back to the server or receive data from the server to further execute some useful action.

Also, in some cases the system works without server. Particularly the device collects data and replies with an action or just provides a user-friendly interface.

However, such cases are quite rare. They are hardly to be regarded as IoT instances as they don’t have an actual connection to the Internet.

Devices should be easily embedded and thereby placed in close proximity to the data sources.

This implies wireless communication, autonomous power supply and high reliability.

The reliability requirement is quite obvious, the questions arise when it comes to wireless technology selection.

The market offers a great variety of options, with such major distinctions to consider as power consumption, range, price, as well as throughput.

The longest range (world wide) is provided by Mobile Networks (2/3/4/5 G) and Satellite Internet access. They ensure good transfer rates, yet are the most expensive options when it comes to subscription price.

Other technologies don’t require a subscription, though their range is a way noticeably shorter. WiFi, BLE, LoRa, ZigBee and 6LoWPAN are among them.

WiFi is the most widespread; it provides high transfer rates, though it consumes the whole battery in a minute. It is used when large amounts of data need to be transferred (video/audio streaming) and power supply is not an issue.

BLE, the last generation of Bluetooth (Low Energy), can also serve as another example of a wireless technology. Among the main advantages are good power consumption rates, long battery life, and high broadcast speed (several hundred bytes per second/minute/hour).

It’s a good choice for different sensors and trackers that should only send or receive small portions of data.

Both WiFi and BLE operate in several hundred meters’ range: up to 500m for Wifi and up to 100m for BLE.

An additional promising young technology under way is LoRa.

Its frequency is lower than WiFi and BLE(433 or 800-900 MHz bands). It has transmission and power consumption rates comparable to BLE and provides operational range up to 15km in rural areas and up to 3km in city.

LoRa is suitable for monitoring large areas, for example applications in the field of agriculture.

As shown above, the customers need to consider a lot of different features and particularities to favor one over another option.

This is the key to gaining success on the market.