Implementation of Arduino in Sensor Integration

Study Case Implementation of Arduino in Sensor Integration for IoT Monitoring Michael Kurniawan (2018123456) University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45221, United States kurniaml@mail.uc.edu Abstract A sensor or transducer is an electronic component that functions to convert a physical quantity into an electrical quantity. With the existence of various types of sensors, various physical phenomena such as temperature, air humidity, air pressure, gas intensity, air quality, etc. can be detected. In measurement/instrumentation activities, the role of sensors is very important. With sensors, changes in the value of a measured quantity can be detected, and these changes can be visualized as the output of a measurement system. Currently, measurement techniques are mostly implemented as integrated systems based on the Internet of Things (IoT). This paper reviews the implementation of various types of sensors in Arduino-based IoT. Keywords: Sensor, IoT (Internet of Things), Arduino, Instrumentation. INTRODUCTION Advances in information technology, electronics, and various other branches of science have enabled various activities to be carried out in an integrated manner. For example, a gas and temperature detection system installed in a gas storage facility. Instrumentation devices are capable of reading environmental conditions such as gas intensity and temperature. These measurable physical values can be visualized in realtime for monitoring purposes. If conditions exceed normal limits, the system will provide an automatic warning (Fauzi, Sulistyo, & Widyawan, 2018). This illustration describes the concept of a system known as IoT (Internet of Things). Microcontrollers were first introduced by the electronics company Motorola in the 1970s through the 6800 series. In principle, a microcontroller is a small computer in an MICHAEL KURNIAWAN 1 Study Case IC (Integrated Circuit) that contains important elements such as memory, CPU, timer, communication channels, input/output ports, and Analog-to-Digital Converter (ADC) (Wilianto & Kurniawan, 2018). Microcontrollers are designed to perform specific tasks. In other words, microcontrollers can be considered mini computers in a single IC chip, typically used in projects that require direct control from the user. Because all the important components of a computer, such as RAM, ROM, I/O, and peripheral devices, are integrated into a single IC, microcontrollers can work without requiring other additional devices. This factor has led to the widespread use of microcontrollers in embedded systems (Adani & Salsabil, 2019). Arduino is an electronic device based on a microcontroller. This platform was developed by Massimo Banzi and his team in Italy in 2005. The programming language used is based on Wiring, which was created by Hernando Barragán, while Processing, a visual programming environment, was developed by Casey Reas in 2001. Arduino is the result of contributions from many scientists, making it open source in terms of both hardware and software. Architecturally, the pins on Arduino are shown in Figure 1 (Heri Andrianto & Darmawan, 2015). Figure 1. Pin Details on Arduino R3 PIN CATEGORIES ON ARDUINO Digital Pins Based on Figure 1, digital pins are labeled D0 to D13. Digital pins have two conditions: High (1) with a voltage of 5 V, or Low (0) with a voltage of 0 V. Digital pins can function as inputs or outputs. When used as inputs, their values are read by the system. When used as outputs, their values can be set as needed. A detailed description of the digital pins is shown in Figure 2. MICHAEL KURNIAWAN 2 Study Case Figure 2. Digital Pin Functions Some pins also have additional functions, such as RX, TX, INT0, INT1, SS, MOSI, MISO, and SCK. Analog Pins In addition to digital pins, Arduino has six analog pins (A0–A5). These pins are directly connected to the ADC, so they can receive voltages between 0–5 V. Analog pins are typically used to read inputs from external sensors. The analog pin descriptions are shown in Figure 3. Figure 3. Analog Pin Functions Pins A4 and A5 also function as SDA (Serial Data) and SCL (Serial Clock Line) used for communication with I2C (Inter-Integrated Circuit) devices. In various applications, analog pins are used to read sensor data, such as temperature, gas, air humidity, and others. MICHAEL KURNIAWAN 3 Study Case Figure 4. Potentiometer Input on Arduino PWM Pins PWM (Pulse Width Modulation) pins are used to generate digital signals that resemble analog controls. The working principle of PWM is to adjust the duration of the High (1) condition in each pulse cycle. An illustration of the PWM principle is shown in Figure 5. Figure 5. Illustration of PWM Duty Cycle Examples of PWM applications include LED intensity control, DC motor speed control, and so on. Arduino has six PWM pins, marked with the symbol “~”, namely pins 3, 5, 6, 9, 10, and 11. SENSORS In various projects, Arduino can be combined with a variety of sensors. The following is a description of several commonly used sensors: Variable Resistor-Based Sensors : LDR (Light Dependent Resistor) Sensor An LDR or photoresistor is a sensor whose resistance depends on light intensity. The lower the light intensity received, the higher the resistance, and vice versa. The characteristics of an LDR are shown in Figure 6. MICHAEL KURNIAWAN 4 Study Case Figure 6. LDR and Its Characteristics Figure 7. LDR Module Circuit with Arduino and Program Code Flex Sensor A flex sensor is used to measure the degree of mechanical curvature. It is shaped like an elastic rod that can be bent, resulting in a change in resistance according to the degree of bending. Details of the shape, installation, and code example are shown in Figure 8. Figure 8. Shape, Installation, and Program Code for Flex Sensor on Arduino Temperature Sensor Arduino can be paired with various types of temperature sensors, such as LM35DZ, TMP36, DS18B20, thermocouple, and infrared temperature sensors. A summary of the types of temperature sensors is shown in Table 1. MICHAEL KURNIAWAN 5 Study Case Table 1. Types of Temperature Sensors Water-Related Sensors Some sensors related to water include: water detection sensors, air humidity sensors, soil moisture sensors, water flow sensors, water turbidity sensors, and pH sensors. Details of these sensors are presented in Table 2. Table 2. Water-Related Sensors Gas Sensors Gas detection devices are important measuring instruments, in which sensors play a major role. Sensors function to convert signals in the form of non-electrical physical quantities into electrical signals, or in other words, convert non-electrical energi into electrical energi. The choice of sensor greatly determines the accuracy of the MICHAEL KURNIAWAN 6 Study Case measurement, so the nature and principle of transduction are major considerations. Examples of measured properties/characteristics and the transduction principles used are shown in Table 4. Table 4. Properties and Transduction Characteristics For gas detection, one of the most widely used ensor sis the MQ-6. This sensor is commonly used to detect LPG (Liquefied Petroleum Gas) leaks, but it can also be used for other gases. Based on several literature sources, the sensitivity of the MQ-6 to LPG is considered to be better than to other gases. The physical form of the sensor and its installation diagram are shown in Figure 7, while its sensitivity to various gases is shown in Figure 8 (Pratama, Muid, & Sanubary, 2019). Figure 7. (a) Physical Appearance of the MQ-6 Gas Sensor, (b) Wiring Diagram of the MQ-6 Sensor MICHAEL KURNIAWAN 7 Study Case Figure 8. Sensitivity Characteristics of the MQ-6 Sensor to Various Gases Figure 8 shows that LPG and methane produce the highest response. Based on the datasheet, the MQ-6 sensor has a detection range of 200–10,000 ppm. The sensor begins active detection at 200 ppm, providing an effective range of 9,800 ppm. When converted to a percentage, 9,800 ppm represents 100%, so each 1% is equivalent to approximately 98 ppm. Distance Sensor and Object Detector This type of sensor is often used in various IoT projects, especially for navigation and robotics purposes. a. HC-SR04 Ultrasonic Sensor The HC-SR04 ultrasonic sensor is used to detect the presence of objects and their distance from the sensor position. Figure 9. HC-SR04 Ultrasonic Sensor and Connection to Arduino Its working principle is similar to a bat's echolocation system. The sensor emits ultrasonic waves with a frequency of around 40 kHz through the transmitter, then the waves are reflected by the object and received back by the receiver. The distance to the object is calculated based on the signal travel time and the speed of sound in the air, which is around 340 m/s. An illustration of the working principle is shown in Figure 10, while the specifications are presented in Table 5. MICHAEL KURNIAWAN 8 Study Case Figure 10. Illustration of How the HC-SR04 Ultrasonic Sensor Works Table 5. Specifications of the HC-SR04 Ultrasonic Sensor b. Line Detection Sensor Line detection sensors are used in robotics applications to follow a path. One commonly used type is the TCRT5000, which uses infrared light. This sensor has two LEDs: one as an infrared transmitter and the other as a receiver. An illustration of the sensor’s shape and connection is shown in Figure 11. Figure 11. TCRT5000 Line Detection Sensor and Connection to Arduino How it works: The infrared LED emits a signal onto a surface. If the surface is a line of a certain color, the infrared light will be reflected and received by the sensor. If a reflection is detected, it is considered a line; conversely, if there is no reflection, it is considered not a line. The physical specifications of this sensor are presented in Table 6. MICHAEL KURNIAWAN 9 Study Case Table 6. Line Sensor Specifications PIR (Passive Infrared) Sensor PIR sensors are used to detect object movement. One example is the HC-SR01. As the name implies, this sensor is passive because it does not emit infrared light, but only detects infrared radiation emitted by objects. The physical appearance of the PIR sensor is shown in Figure 12. Figure 12. PIR Sensor and Connection to Arduino The PIR sensor has three main pins: • VCC: connected to a 5 V DC power source on the Arduino. • GND: connected to the Arduino ground. • OUT: connected to the Arduino digital pin. The output can be High if motion is detected, or Low if there is no motion. MICHAEL KURNIAWAN 10 Study Case CONCLUSION Sensors are fundamental components in various IoT applications. The presence of various sensors enables the measurement of physical conditions in the environment, such as temperature, pressure, humidity, gas, object presence, color, and radiation. When sensors are combined with Arduino, the device can function as an instrumentation system for real-time data monitoring and analysis. In addition to data visualization, the integration of Arduino and sensors also supports further analysis, such as classification, pattern detection, and clustering. In more complex cases, the system can be enhanced by embedding training data to support the application of artificial intelligence. Thus, the use of sensors with Arduino not only produces IoT devices for monitoring, but also opens up opportunities for machine learning-based intelligent systems. REFERENCE MICHAEL KURNIAWAN 11