IoT – Popular Sensor with the Specification

Introduction

In this article, we are going discuss the most popular sensor with properties in IoT Platform. Nowadays the sensor having the most important role of electrical devices. Sensor – Converts physical quantity into an electrical or digital signal.

** Target Audience –** Beginners

** Topics**

• Humidity and Temperature Sensor
• Temperature Sensor

• Proximity Sensor

  • Inductive Sensor
  • Capacitive Sensor
  • Optical Sensor
  • Ultrasonic Sensor

• Accelerometer

• PIR Motion Sensor

• Image Sensor

• Gas Sensor

  • Air Quality Sensor
  • Smoke Sensor

• IR Sensor

• Level Sensor
  Humidity and Temperature Sensor

    The Humidity and Temperature Sensor are used to measure the moisture and temperature of the surrounding air. The different temperature sensors are designed based application with analog and digital output. Example LM35 and DHT11, DHT22. The Automation application widely used DHT11 sensor, because of output in digital form. The digital data comes from the data pin in every 2 seconds. In here we discuss the specification of DHT11  
  

DHT11 Pin diagram

Figure 1 DHT11 Sensor
Pin Definition

1. Vcc – Input voltage
2. GND – Ground pin
3. NC – Non-Connection pin (In this pin need to add SOIC14 fabrication)
4. Out - Digital data output.

Specifications

| Operating Voltage | 3.3 to 5V DC |
| Measuring Range | 20-95%RH (Relative Humidity) ；0-50℃ |
| Resolution | 8-bit Humidity, 8-bit Temperature |
| Interfaces | 3-Pin interfaces, 4-pin interfaces |
| PCB Size | 22.0mm X 20.5mm X 1.6mm |

Temperature Sensor

     This sensor used to measure the temperature of the surrounding and the output voltage linearly-proportional to Centigrade temperature. The operating voltage is 4 – 30V and it is an analog sensor. Based on an application designed various transistors.  

Pin diagram Specification

Figure 2LM35
Specifications

| Operating Voltage (V) | 4-30 |
| Operating Temperature (C) | -40 to 110, -55 to 150, 0 to 100, 0 to 70 |
| Supply current (uA) | 114 |
| Output | Analog Output |

Proximity Sensor

       The sensor is able to detect a range of objects with the help of emitting an electromagnetic field or a beam of electromagnetic radiations without any physical contact. It can also be used to recognize air gestures and hover-manipulations.  

Figure 3 Proximity Sensor
Pin Diagram

1. Vcc – 5V Power supply
2. Out – Data output
3. GND – Ground There are 4 types of Proximity Sensor
4. Inductive Proximity Sensor – it is an electromagnetic sensor to detect the metallic object without touching them and operating principle coil and high-frequency oscillator. The coil and oscillator create a magnetic field in surrounding surface. The range of detection based on coil size. It will detect only metallic objects. ** ** ** Applications** · Car Parking Area · Industrial application.
5. Capacitive Proximity Sensor – It’s a Non-contact Metallic object and Non-Metallic objects like water, plastics. The measure the variation of capacitance between sensor and object and Range of distance one Micro Inch can be measured. The object comes near the sensor Capacitance increases and objects move away Capacitance Decreases. ** ** ** Applications** ** ** · Mobile Phones · Laptops · Computer displays
6. Optical Proximity Sensor – It’s a non-metallic sensor to detect the object and measure the distance between object and sensor. The working principle of Optical sensor is the action of the light move are made up of Transmitter (Light source) and Receiver (Light detector). When the transmitter transmits light sources and the object will reflect the light source, the object reflects to be a receiver (Photodiode). ** Applications** · Security · Automobile · Distance measured · Level sensing
7. Ultrasonic Sensor – The Ultrasonic sensor or Ultrasonic transducer one of most popular sensor used in many of applications in IoT. ** ** Working Principle: The Transmitter transmits the ultrasonic waves in the air of forwarding direction and when an object is there, it will reflect towards the receiver. The receiver (Photodiode) receives the ultrasonic waves. ** **

Distance = Speed x Time

Now, we should know the speed and distance, then calculate the distance of the object.

Figure 4 Ultrasonic Sensor
Pin Definition

| 1 | Vcc | 5V Power supply |
| 2 | Trig | The trigger pin is an input pin. It will have kept high for 10uS |
| 3 | Echo | Output pin. |
| 4 | GND | Ground pin |

Specifications

| Theoretical Measuring Distance | 2cm to 450cm |
| Practical Measuring Distance | 2cm to 80cm |
| Accuracy | 3mm |
| Operating Current | <15mA |
| Frequency | 40Hz |

Applications

• Robots

• Vehicles
  Accelerometer

    This sensor now presents in millions of smart devices. Like a smartphone, anti-theft protection, etc. Working Principle is the mechanical energy converts into the electrical signal output. It is defined by the rate of change of velocity with respect to time.  
  

Figure 5 Accelerometer
Pin definition

Figure 6 Pin diagram of Accelerometer

| Vcc | + 3 to +5V |
| Ground | Ground of System |
| SCL | Serial Clock through I2C Communication |
| SDA | Serial Data through I2C Communication |
| XCL | Clock Interface other I2C modules (Optional) |
| XDA | Data Interface other I2C modules |
| ADO | More than 1 sensor in MCU, then this pin used to vary the address |
| Interrupt | Data is available on the chip to read the MPU |

Specification

• · Communication – I2C Protocol
• · 16-bit ADC
• · Interface other I2C
• · Configurable ICC Address

Applications

• · Car
• · Drone

• · Smartphones
  PIR Motion Sensor

  The PIR Motion sensor Stands for Passive Infrared Sensor. It can sense to detect the presence of human or animals. The Output voltage of Sensor is 3.3V. It has one Trigger Section for Repeatable and Non-Repeatable mode. In the Repeatable mode detect the human output pin voltage goes low but the non-repeatable mode cannot go low output when the object moves out in the range, it will go low. The inside of the sensor Pyroelectric sensor was attached.

Figure 7 PIR MOTION Sensor
Pin Diagram Specification

| Power Supply | 4.5 – 12V |
| Output Power | 3.3V when Motion detect output is low (0V) |
| Ground | Connect to ground |
| Time Delay | Rotate to Adjustment |
| Sensitivity | Rotate to Adjustment |
| Trigger Selection | Repeatable and Non-Repeatable mode |
| Angle of sensing | 110 to 90 degrees |

Applications

• · Security Cams
• · Alarms
• · Garden Alarms

• · Automation Control
  Image Sensor

  The Image sensors are used to convert optical images to electrical signals, the camera device used to capture the light. The color-blind CMOS Sensor ability to respond to the various color of light. The Microlens are used to focus incoming signal. It is One of the popular sensors in the industry.
  
  
  
  Applications

• · Radar

• · Sonar

• · Night Vision equipment

• · Car Manufacturing industries
  Gas Sensor

   It is used to monitor changes in air quality and to detect the presence of various gases. In this sensor mostly used in manufacturing industries, Space station, and chemical industries. The alternative gas sensor is available but the mostly MQ2 used in IoT industries.  
  

Different Gas Sensor

• · Carbon dioxide sensor
• · Breathalyzer
• · Carbon monoxide detector
• · Catalytic bead sensor
• · Hydrogen sensor
• · Air pollution sensor
• · Nitrogen oxide sensor
• · Oxygen sensor
• · Ozone monitor
• · Electrochemical gas sensor
• · Gas detector
• · Hygrometer

MQ2 Sensor

| DOUT | Digital Output 0 to 5V |
| AOUT | Analog Output 0 to 5V |
| GND | Ground |
| Vcc | 5V |

Applications

• · Laboratory
• · Chemical Factory

• · Industries and etc.
  IR Sensor

  The IR sensor used for a remote application like TV Remote. The Sensor LED emitted Infrared Radiation and The Photodiode can receive Infrared radiation. In IR radiation is transparent.

Pin Definition

| Vcc | +5V |
| GND | Ground |
| Out | Digital Output |
| Current Supply | 20mA |
| IR Emitter | LED |
| IR Receiver | Photodiode |
| Trigger | Adjust Distance |
| Power LED | Device condition |
| Obstacle LED | Obstacle detection notification |
| Range | Up to 20cm |

Applications

• · Remote Control

• · Industries Safety
  Level Sensor

      The level sensor used to monitor the level or amount of liquid. It only indicates whether the substances are above or below of sensing level. The different types of level sensor are manufactured based on application.  
  

Types

• · Capacitive level
• · Ultrasonic level
• · Vibrating level
• · Optical level

• · Microwave level
  
  
  Applications

• · Oil Manufacturing Plants

• · Water Treatment

• · Power Generating Plant

• · Waste material handling industry.

Conclusion

I hope we are learned some of the popular sensor with its properties in IoT. Thank you for reading this article.