Design and Implementation of a NodeMCU-Based Home Automation System

Study Case Design and Implementation of a NodeMCU-Based Home Automation System with Web Server Integration Michael Kurniawan (2018123456) University of Cincinnati, 2600 Clifton Ave, Cincinnati, OH 45221, United States kurniaml@mail.uc.edu Abstract Technological advances encourage humans to continue creating innovations that can simplify work and improve efficiency. One of the latest developments is the Internet of Things (IoT) system, which allows users to control electronic devices via the internet. When traveling, people often forget to turn off devices such as lights, fans, or air conditioners (AC). Based on this condition, this study designed a NodeMCU-based home automation system that can control lights, fans, AC (simulated with three lights), and gate doors driven by DC motors through a web server. The server was developed using Bluehost.com hosting services with PHP programming language, as well as 4G LTE and HSPA+ internet connections on NodeMCU ESP-12E. The test results showed that the system worked well, providing a very fast response on a 4G connection. Keywords: Internet of Things (IoT), home automation, NodeMCU INTRODUCTION Current technological developments have encouraged humans to create various innovations that simplify daily tasks and increase productivity. For example, in household life, one needs to turn lights on or off inside the house and in the yard. When residents are resting or outside the house, these actions can be inconvenient. Often, people also forget to turn off electronic devices such as lights, fans, or air conditioners when traveling. The proximity of modern humans to smartphones makes them an ideal means of controlling various home devices remotely. Internet of Things (IoT) technology enables MICHAEL KURNIAWAN 1 Study Case the realization of home automation systems, which is now a broad research topic. Previous research, such as that conducted by Ellian Adhi Satya, developed an internet-based lighting control system using Arduino Uno connected to the ESP8266 Wi-Fi module and the IoT Thingspeak platform [1]. Another study by Dika Ardi Kurniawan designed a remote on/off control system for lights and air conditioners based on Arduino Mega 2560 with Ethernet Shield, which is accessed through a local web server address. Users can turn devices on or off through a web page, where Arduino sends infrared (IR) signals to the air conditioner via IR Transmitter, and monitors room temperature through sensors [2]. Research by Mochamad Fajar Wicaksono implemented the NodeMCU ESP8266 Wi-Fi module to control fans and lights based on the conditions of the DHT11 (temperature/humidity) and LDR (light) sensors. This system also sends the status of the house to the server and can send email notifications to users [3]. Meanwhile, Zulfauzi developed an Android-based automatic sliding door using a Wi-Fi network and Arduino Uno microcontroller. The Android application functions as an input to open and close the door, while a DC motor is used as a mechanical drive [4]. Finally, research by Arafat discusses the design and implementation of a Wi-Fibased smart home system using Arduino Uno with the Blynk IoT platform accessed via an Android smartphone. This system includes light control based on an LDR light sensor, a door opener with RFID, a smoke detector using an MQ-2 sensor, and an automatic water level regulator using an HC-SR04 sensor [5]. Based on these studies, this research developed an IoT system capable of controlling lights, fans, and air conditioners (via relays), as well as automatic gate doors driven by DC motors. All devices are controlled through a web server hosted on Bluehost.com, with NodeMCU ESP-12E as the main Wi-Fi module METHODS Hardware Design The system consists of two main parts: light control and automatic gate control. This system requires an internet connection for communication between the NodeMCU microcontroller and the web server via the ESP8266 Wi-Fi module, with a relay as an on/off switch. For gate control, a stepper motor is used, controlled via web server commands and MICHAEL KURNIAWAN 2 Study Case regulated by Arduino. The overall block diagram of the system is shown in Figure 1. Figure 1. Hardware Design Block Diagram Figure 1 shows the main flow of the web-based control system for regulating the relay and household appliances. The main components are described as follows: • Web Server: Functions as the control center for lights and relays, and displays the status of devices in real-time (ON/OFF). The server is accessed via the URL: http://smarthomecontrol.com/home_automation. • NodeMCU ESP8266-12E: Serves as the main microcontroller and internet data connector. • Relay: Functions as an electronic switch to disconnect or connect the current to the lights, fans, and air conditioners according to instructions from the web server. • Lights, Fans, and Air Conditioners: Are the system test devices. • DC Motor: Used as a home gate drive, with a limit switch to automatically stop the motor's movement. NodeMCU NodeMCU is an open-source IoT platform that combines the ESP8266-12 module from Espressif Systems and Lua scripting firmware [6]. NodeMCU functions like an Arduino board, but with the added capabilities of built-in Wi-Fi connectivity and a USB-to-Serial interface. MICHAEL KURNIAWAN 3 Study Case In general, NodeMCU has several production versions—such as Amica, DOIT, and Lolin/WeMos—with V1, V2, and V3 variants. The second version (V2) uses the ESP12E chip and CP2102 USB-to-Serial IC, which are more stable than the previous versions. Figure 2. NodeMCU Devkit v1.0 ESP-12E ESP-12E is the core of NodeMCU that provides Wi-Fi connectivity and data processing capabilities. NodeMCU firmware is built using the eLua API, which is similar to JavaScript in terms of event-driven programming. Some of the main features of the ESP-12E include [7]: • 10 GPIO ports (D0–D10) • PWM (Pulse Width Modulation) support • I2C and SPI interfaces • 1-Wire interface • One ADC (Analog to Digital Converter) channel Figure 3. ESP-12E module Relay A relay is an electronically operated electromagnetic switch. When electric current is passed through the coil, a magnetic force is generated that attracts the armature and changes the contact position from Normally Open (NO) to Closed, or vice versa. In general, a relay consists of two main parts: an electromagnetic coil and mechanical contacts (switch contacts). The following is a basic relay diagram as shown in Figure 4. MICHAEL KURNIAWAN 4 Study Case Figure 4. Basic Relay Circuit Diagram Explanation of the elements in Figure 4: • Armature – A metal lever that moves when exposed to a magnetic force. • Spring – A spring that pulls the armature back to its original position when the magnetic force disappears. • Shading Coil – A protective component for AC current from the electrical network. • NC Contact (Normally Closed) – A contact that is connected by default when the system is OFF. • NO Contact (Normally Open) – A contact that is active when the system is ON. • Electromagnet – A coil of wire that generates a temporary magnetic field when electrified. • Trigger Circuit – A trigger circuit that activates a relay under certain conditions, usually based on a sensor or timer. DC Motor A DC (Direct Current) motor is an actuator that converts direct current electrical energy into mechanical motion energy. The main components of the motor consist of a stator (stationary part) and a rotor (rotating part). DC motors have two terminals and are driven by a direct voltage source. Figure 5. DC Motor MICHAEL KURNIAWAN 5 Study Case L298N Driver The L298N motor driver is a popular module used to control the direction and speed of DC and stepper motors. The main component inside is the L298 IC, an Hbridge type, which allows control of inductive loads such as motors and relays. This IC is equipped with NAND gate-based TTL logic transistors, which facilitate the control of motor rotation direction. The L298N module is known for its high precision in controlling motor speed. Figure 6. L298N Driver Module Software Design 1. Web Server A web server is software that provides data-based services, functions to receive requests from web browsers via HTTP or HTTPS protocols, and sends the results in the form of web pages, generally in the form of HTML documents. The main function of a web server is to transfer files requested by users through a predetermined communication protocol. The requested web pages usually contain elements such as text, images, videos, and other multimedia files. Thus, the web server ensures that all components of the web page—both text and media—can be sent correctly to the client [9]. 2. Web Server Implementation In this study, the web server was implemented using a paid hosting service comparable to commercial hosting providers in the United States such as Bluehost or HostGator. This hosting platform utilizes cPanel as a control panel for web management, as well as phpMyAdmin for MySQL database administration, with PHP as the server-side programming language. The web application can be accessed via the domain https://homeautomationmonitoring.com, which functions as the main page for the automatic lighting and gate control system. On this main page, there are ON/OFF buttons to control the lights, fans, and air conditioners, as well as OPEN/CLOSE buttons to control the gate motor. Below MICHAEL KURNIAWAN 6 Study Case the control area is a device status table that displays the current status of each system component. Figure 7. Main Page Display of the Light and Gate Motor Control System The first step in creating a web server is to create a database in phpMyAdmin. After the user logs into the hosting account, the Login to cPanel menu is used to open the main cPanel dashboard, as shown in Figure 8. Figure 8. Hosting Account Dashboard Page After logging into cPanel, several important menus are used in this research process, including File Manager in the Files section, as well as phpMyAdmin and MySQL Databases in the Databases section. To create a new database, the user clicks MySQL Databases, then enters the database name (for example, automation_db). The newly created database will appear in the Current Databases list and can be changed or updated as needed (Figure 9). MICHAEL KURNIAWAN 7 Study Case Figure 9. cPanel Main Menu The next step is to create a new user account for the database. The username is created in a format such as auto_user, accompanied by a strong password. After that, the user is linked to the database through the Add User to Database menu. In this study, the auto_user account is linked to the automation_db database. The next process is carried out in phpMyAdmin, where the database that has been created can be viewed and managed. In this study, a table named relay was created, as shown in Figure 10. Figure 10. phpMyAdmin display with the “automation_db” database To create the relay table, click New under the database name, then fill in the columns with the following parameters: Once finished, click Save, and the relay table will be successfully created (Figure 11). Figure 11. Process of Creating the “relay” Table MICHAEL KURNIAWAN 8 Study Case RESULTS AND ANALYSIS Testing of the NodeMCU-based home automation system was conducted to analyze response time using two different internet connections, namely HSPA+ (AT&T) and 4G LTE (Verizon). The testing process began by accessing the page https://homeautomationmonitoring.com/index.php, then pressing the control buttons one by one to activate or deactivate the lights, fans, air conditioners, and gate motors. A stopwatch was used to measure the time from when the button was pressed until the device responded. 1. Response Time Testing between HSPA+ and 4G LTE Connections The purpose of this test is to compare the system response speed between HSPA+ (AT&T) and 4G LTE (Verizon) connections. The test with HSPA+ was conducted because NodeMCU cannot function optimally if the signal is below that speed (e.g., 3G). Each test was conducted three times to obtain the fastest, slowest, and average time data. The results of the HSPA+ connection test from AT&T are shown in Table 1. Table 1. Response Time Test Results with AT&T HSPA+ Network The results show that: • System initialization had an average time of 4.35 seconds (maximum 6.67 seconds, minimum 1.39 seconds). • Lights ON averaged 1.38 seconds, Lights OFF 1.97 seconds. • Fan ON 22.29 seconds (sometimes increased due to signal drop to 3G), Fan OFF 0.57 seconds. • AC ON 0.48 seconds, AC OFF 2.49 seconds. • Gate motor ON 17.43 seconds, Motor OFF 10.61 seconds. The next test was conducted using the Verizon 4G LTE network, which showed much more stable and faster performance (Table 2). MICHAEL KURNIAWAN 9 Study Case Table 2. Response Time Test Results with Verizon 4G LTE Network The test results show that: • System initialization averaged 5.46 seconds (maximum 7.61 seconds, minimum 1.84 seconds). • Lights ON averaged 0.57 seconds, Lights OFF 0.73 seconds. • Fan ON 0.47 seconds, Fan OFF 0.43 seconds. • AC ON 1.09 seconds, AC OFF 0.57 seconds. • Gate motor ON 0.60 seconds, Motor OFF 0.53 seconds. CONCLUSION Based on the test results, the HSPA+ (AT&T) connection often experiences a decline in network quality, which causes communication between NodeMCU and the web server to be interrupted, resulting in slower response times. In contrast, the 4G LTE (Verizon) connection provides better results, with fast response times and a much more stable connection. Overall, system performance is greatly influenced by the stability and speed of the internet connection, as well as external factors such as the test location, time of execution, and the accuracy of time measurements using a stopwatch, which can cause slight differences in results. MICHAEL KURNIAWAN 10 Study Case REFERENCE MICHAEL KURNIAWAN 11