This is second in series of blogs on Internet of Things – For the first blog read here.

In this blog we would discuss on how to make things communicate. i.e. how to make things tell what they know, what they see and feel or hear.

To understand this better let first understand how humans communicate with others – Humans tell what’s going around by using their senses – Hear, See, Touch, Smell and Taste – Humans use these 5 senses to gather information and this information is sent to the human brain for analyzing. The brain analyses this information and provides results and humans respond accordingly (speak, write or move, cry, laugh etc.)

In short – Humans use senses, analyze it and respond accordingly to communicate with the outer world. There are three things important here – Sense, analyze and respond in a certain way.

To make “THINGS” that can Sense and Respond (in order to communicate)  to the world around them is called – Physical Computing.

Physical Computing – It’s a science of building interactive system for communicating with outer world).

So to make the “Things” able to communicate, so that they are part of IOT – they need to use small devices called as Sensors.

Sensors – are small devices when attached to things – make things sense what’s going on in the world around them and there for communicate what they can see, hear and feel.

Sensors are small (tiny), easy to use electronic devices, that can measure changes in the world around them and can sense changes that are happening around them.

They are different types of sensors, below table list a few sensors commonly used and they functionality.

Sr.No. Sensor Use Sense
1 Light Sensor Use to sense light – bright light or day See
2 Proximity Sensor To measure distance of object how near or far. See
3 Pressure Sensor To measure the pressure Feel
4 Heat Sensor To measure heat or cold Feel
5 Motion Sensor To measure the speed / how fast object is moving Feel

Now that we know – using sensors we can makes things to sense – the second part is analyze.

For analyzing the information that is sent by the things using sensors, we cannot use the normal computer / desktop. As a desktop computer is UBIQUITIOUS – i.e. it has a standard input and output ( files, keyboard, mouse, touch, print, screen etc.) and it takes information from fixed input, processes it and gives the result to the standard output.

This means a desktop computer / machine do not have an interface to connect a sensor as input and analyze the result and provide a response, So Micro-controllers are used to connect Sensors.

Micro-controllers are small computers that can interact with Sensor using the pins (GPIO pins ) on them. These pins are used to attach the sensor for reading the info,  this info is analysed using a pre-stored program and providing a response.

The GPIO (General Purpose Input Out) pins are used to connect a large variety of sensors, these pins are configurable based on the need, they can be converted to input or output as required. The Micro-controllers have programs stored inside them using assembly language, these programs analyze the input coming from the sensors and provide a response. The response in not the normal output which we get from computers and so in the physical computing world is called Actuators. So in Micro-controllers (Input is Sensors and Output is Actuators).

Note: There is still a problem here, because Micro-controllers programs are written using low level Assembly language – which difficult to write and very difficult to understand.

There is a need of a special computer that can are able to connect to the sensors, easy to program (code using simple human readable programming language) for analysis and provide a response (actuators) back in the form which sensors can understand or humans can understand for taking next steps.

The solution to this problem is a small tiny computer – (with just the CPU and Main memory and GPIO pins, No Secondary Memory and No standard input or output devices) – called the Raspberry Pi and the Arduino.

In the next article we would talk briefly talk on Raspberry Pi and Arduino and in future articles we would be learning about Raspberry Pi in detail.

Happy Makers 🙂

Internet of Things (IOT) – II How to make things Communicate

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