Before getting into ADC of AVR, let us discuss automation in the machine. So, what does it take to make a machine autonomous? Humans are the autonomous machine, so what does it take to become autonomous? The answer is sensors. Humans have 5 senses namely -vision, smell, taste, hearing, and touch. Therefore, in order to make a machine autonomous, we have to interface it with sensors. In order to interact with the environment, we need sensors. Therefore, an automatic machine should have sensors in order to be able to interact with its environment and take decisions. This article introduces you to different types of sensors which are used in automation.

So What is Sensors?

A sensor is any device capable to measure a physical parameter by converting it to electrical signals for further processing of the signal. Take an example of a simplest of automation robot-a Line Follower robot or a very complex Robot, they all have sensors. The simplest Robot like line follower may have one or two types of sensors like-Proximity sensor and an IR sensor. A complex humanoid has various sensors like camera, acoustic sensors, accelerometer, etc.

Sensors-What can we measure using Sensors?

There is only one answer-”anything”. There are sensors for measuring temperature, pressure, vision, humidity etc. Needless, to say that there are different sensors for different measurement-For example, the proximity sensor can be implemented by IR sensor or by an ultrasonic sensor, the temperature is measured by temperature sensors like a thermistor, thermocouple etc. Every sensor has three things

  • Vcc
  • Ground
  • Output

Vcc– As the name suggests, it is used to give supply to the sensor. Ground- the 2nd terminal of Supply Output- The terminal which gives output. Now the majority of sensors gives analog voltage as an output, but there are some exceptions. The sensor senses the physical parameters and gives a corresponding output. In most cases the output is analog. Some of the most common sensors used in the field of robotics and embedded systems are as follows:

  • IR Sensor

This sensor is based on Infra-Red Sensor. The concept behind this sensor is very simple. It releases the IR waves and waits for it to receive it. If the object is present, IR waves got to reflect back and the sensor receives it and gives analog output according to the intensity of the wave reflected.

IR Sensor-Introduction


  • LM35 Temperature Sensor

This sensor is very simple to use. It gives analog voltage as an output according to the temperature of its environment. Besides this, there are other sensors as well for measuring temperature like a thermistor, thermocouple etc. Temperature sensor Introduction

  • Accelerometer Sensor

    An accelerometer is used to measure the inclination in any axis. It’s present in your mobile, and it’s because of this little device, you are able to play inclination based games like-Asphalt 8, Real Racing 3 etc. It is used to make gesture-based devices where you have to measure inclination.

Accelerometer -Introduction

  • Ultrasonic Sensor

    This sensor can measure distance using sound waves. The distance is measured by transmitting an ultrasonic wave and waiting for it to hitting it back to the receiver.


Well, these are just different types of sensors and there are still much more sensors needed to discuss. This article is just for the introduction of sensors and it’s implication on robotics. In the further post, you will learn about ADC-Analog to Digital conversion, which is needed for interfacing these sensors with our very own, Atmega-16.

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