The role of sensors in IoT applications is most significant since the sensors collect data to drive the application. The sensor is an important component of an Internet of Things (IoT) application and plays a vital role in the working of the application. Sensors let us know about our environment in which we are living and working. Sensors allow us to collect data about our surroundings and help us extract information from this data.
However, sensors can’t operate on their own. They need the brain in the form of microcontrollers that drive them. Microcontrollers make the sensors smart.
Basically, sensors detect some physical quantity like temperature, pressure, humidity or the presence of light and convert it into analog or digital format which in turn is read by the microcontroller for further processing and storage.
We can summarize the role of sensors in IoT with following illustrations.
Gaining Insight of the environment.
We can measure the physical environment conditions using sensors. For instance, we can detect rise and fall in temperature, presence of light, smoke, gas, and alcohol as well as the relative humidity. Sensors provide us so many features that we can realize automation everywhere.
Enabling Smart Decisions
The data collected by sensors help us in making smart decisions. For instance, if a sensor detects that nobody is present in the room it may alert the user to turn off the Air Conditioner.
Prediction of future conditions
We can analyze the data collected by sensors using machine learning algorithms to predict future outcomes. Regression analysis also helps us in predicting the future value of a variable. For instance, we can predict the rainfall in the near future.
Types of Sensors
We can categorize the sensors in many ways. For example, sensors can be passive or active. Also, the sensors can be digital or analog. Further, we can also classify sensors on the basis of physical property that they measure. Here is our list
Sensors for Environment Conditions
- Temperature sensors measure the change in temperature by measuring the amount of heat energy generated from objects or the atmosphere. Examples are DHT11, DHT22, LM35, I2C BME280, etc.
- Humidity sensors measure relative humidity by detecting the amount of water vapor present in the air. DHT11 and DHT22 also measure relative humidity. Other examples are SHTW2, SHT85, etc.
- Pressure sensors determine the pressure applied by liquid or gas. More information on pressure sensors is available here. You can use SPD005G or BMP180 pressure sensors with Arduino.
- You can measure the flow of liquid and gases by using a flow sensor. flow sensors have many industrial applications, particularly in the oil and gas industry. Moreover, the flow sensor can also detect clogged pipes in residential buildings. With the Arduino board, you can use flow sensors like OLatus YF-S201.
- sensors like MQ2 and MQ3 measure gas, smoke, and alcohol. You can use these sensors with Arduino. These sensors not only have lots of industrial applications but they are used in residential buildings also.
- Light sensors measure the brightness of the light source. These sensors can detect how far the light source is and have applications in smartphones and tablets, automatic street lights in smart cities, vehicles, and smart greenhouse.
Sensors for Industry, Home Automation and Safety
- IR sensors measure infrared radiations. These sensors are widely used in safety and surveillance applications where night vision is required. Additionally, they are also used in astronomy.
- Proximity sensors detect the presence of some object. We can use these sensors in the home safety applications as well as in autonomous vehicles and parking lots. VCNL4010 is an example of a proximity sensor.
- Color sensors are used in color detection applications in paint, textile printing industry. We can use the TMD37821 color sensor with both Arduino and Raspberry Pi.
- Tilt sensors, also known as inclinometers or slope sensors, measure the angle of an object with respect to the force of gravity. These sensors have applications in smartphones, cameras, automobiles and aircraft, human posture detection, and robotics.
- Touch sensors measure the force applied to the sensor and hence detect the touch. These sensors have applications in smartphones and tablets and home automation.
- Ultrasonic sensors measure the distance and have applications in connected vehicles, parking lots, robots, and UAV navigation.
- Accelerometers detect vibrations and they have applications in navigation and automobiles. For example, you can use an MPU6050 accelerometer with Arduino.