Sensors Introduction

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In one of my previous post I briefly talked about sensors and their importance and usage in IoT scenarios.

In this post I will write about different type of sensors, their capabilities and usage.

  • Electronic components are discrete device that somehow modify the behavior of an electronic system.
  • Sensors are simply systems of electronic components that are designed to detect or measure information and interactions, convert them to an analog or digital electronic signal and make it available as an input to the IoT device.
  • Sensors are the little nerve tips into the world that bring back information that you can use in the operation of whatever device you are building. Sensors make it information or actions for people or their environment. Lets see a few examples.

Simple Button

Fundamentally a button is a way for humans to interact with the device. Electronically, buttons causes the completion of a circuit. So if you design your circuit right, you can easily make it so that a press of the button delivers a 5 volt potential to a digital input pin. Whereas a release of the button drops the voltage to zero. The value of 5V or 0V is then translated by your processor as logic level a 1 or a 0, a true or false.

Temperature Probe

Obviously a temperature sensor can be used to relay information to your device about its environment. The metal end can be placed in whatever location you want and temperature will affect the resistance b/w the two wires at the other end.

Photo Cell

The photo cell detects the light level instead of the temperature level. That would provide a variable resistance just like the temperature sensor and like the temperature sensor you would use a voltage divider circuit to pickup the value and bring it to an analog pin to make it available to your program and suddenly you program knows the level of light in the room.

Line Sensor

The line sensor introduces a little bit more complexity. This is actually a small circuit board as apposed to a simple component. To start with, try to find its data sheet online to confirm the voltage levels, electrical, optical characteristics, performance curves etc.

Flex Sensor

Its going to vary its resistance value according to how much you bend it.

Ultrasonic Rangefinder

It’s a fun little device, looks like robot eyes. In fact, however, one of the two obvious cylinders is a sonic emitter and other one’s a collector. This rather intelligent sensor sends out a sonic pulse; little pulse of sound that you can’t hear and then it picks it up and allows you to do some simple math to figure out how far away the nearest object is.

MG811 CO2 Sensor

It can be used in the detection of unwanted gas in a home.

MPL3115A2 Altimeter and Barometer

It is a sensitive and rather complex device, it determine its ambient air pressure and does all the necessary calculations to translate that into an actual altitude reading. Its so sensitive that it can determine differences in altitude as small as 1 foot.

Summary

The components we have seen so far are called sensors. They allow the board to detect things about its environment. There are many more type of sensors available and in upcoming posts we will be using those for our IoT Projects. Till next time, Happy Coding.

References