An Inventory Tool for Receiving Practicum Report Based on IoT by Using ESP32-CAM and UV Sterilizer: A Case Study at Muhammadiyah University of Sidoarjo

– Currently, there are several problems related to practicum report collection in the electrical engineering laboratory at the Muhammadiyah University of Sidoarjo. The first problem is the presence of crowds during practicum report collection that have their dangers, specifically during the Covid-19 pandemic. Another problem is the absence of laboratory assistants in the electrical engineering laboratory when there are students who will collect reports. A tool that can receive practicum reports was made from these problems, and it can be monitored remotely by a laboratory assistant. By putting an RFID card to the RFID sensor on the box so that the solenoid can open the box door and the student can put the report into the box. At the same time, ESP32-CAM takes pictures of students collecting the report. Then, notification in the form of photos and student information will be sent to the laboratory assistant through the Telegram application. After the report is placed into the box, the UV Sterilizer will turn on to disinfect the report. The expectation of making this tool is to facilitate the collecting report process of practicum results and reduce the crowd in the laboratory.


I. Introduction
From March 2020 until today, Covid-19 positive cases in Indonesia have reached more than 4 million people [1] [2]. Its easy transmission makes the spread of this virus extremely fast [3]. To break the transmission chain, the government limits many communities from doing activities outside the home, crowding, doing social distancing, and disinfecting goods periodically [4]. The electrical engineering laboratory of Muhammadiyah University of Sidoarjo is one of the parties affected by the Covid-19 virus, which makes students have to do online lectures, even though the practice cannot be done optimally online. Lack of student discipline in social distancing implementation when collecting practicum reports creates dangers. Another problem related to practicum report collection is when students' collecting practicum report results, the laboratory assistant is not in the electrical laboratory. Therefore, students leave the report to another laboratory assistant or put the practicum report result in any place that causes the practicum report to be damaged or lost. From these problems, a tool is made to receive practicum reports that can be monitored remotely. This tool is equipped with ESP32-CAM and UV Sterilizer. This tool can receive practicum reports by putting an RFID card on the RFID sensor; then, the ESP32-CAM will send photos and student group information through the Telegram and Google Sheets applications. After the report is placed into the box, the report will be sterilized with a UV Sterilizer. Therefore, practicum reports are spared from viruses.

I.2. RFID
Radio Frequency Identification (RFID) is a method that uses radio waves. It is used to track, store, and identify information utilizing an RFID tag device [7] [8].

I.3. Selenoid door lock
Selenoid door lock is an electronic component that uses electromagnetic working principles. It can be used when given a voltage of 12 Volts [9].

I.4. LCD 20x4
LCD (Liquid Crystal Display) is a tool that can display the value of a sensor, display writing, and display menus on the microcontroller [10].

I.5. UV sterilizer
Ultraviolet light (UV light) is a type of electromagnetic radiation with wavelengths ranging from 4nm to -400Nm. UV light technology is an easy and simple non-chemical disinfection method [11][12] [13].

I.6. Telegram
Telegram is a messaging service app with a focus on speed and security. Telegram can be used on all work devices at the same time. The messages can sync seamlessly across any phone, tablet, or computer (Windows, Mac, and Linux) [14].

I.7. ESP32-CAM
ESP32-CAM is a camera module used for indoor and outdoor monitoring. This module is also equipped with Bluetooth and WiFi, designed like a microcontroller [15].

II.1. System block diagram
There were three parts in this box: input, process, and output. In the input section there was RFID as an input to open the box. In the process section there were Arduino Mega microcontrollers, NodeMCU ESP8266 and ESP32-CAM. Arduino Mega was used to verify RFID inputs and control Selenoid door lock relays, and UV Sterilizers. NodeMCU ESP8266 was used to send notifications to Telegram and Google Sheets. The ESP32-CAM was used to send photos to Telegram. In the output section there was a 20x4 LCD to display the commands and conditions of the tool, Selenoid door lock as a tool door safety, UV Sterilizer as a sterilizer when the report was entered into the box, Telegram and Google Spreadsheet as a recapitulation of incoming data. Fig. 2 shows the system block diagram in this research.

II.2. Program flowchart
The program began with a WiFi connection. If the WiFi has connected the RFID card to the RFID sensor could be placed. After the RFID card was verified, the Selenoid door lock would open. After the door was opened and the report was entered, ESP32-CAM would take pictures of students collecting reports. After that, NodeMCU ESP8266 would send a message in the form of group information and students' photos who had collected reports via the Telegram application. The data would also be stored on Google Spreadsheet. The Selenoid door lock would automatically close after 30 seconds. After the box door was closed, the UV Sterilizer would be active to sterilize the practicum report. Finally, the LCD would display the text that the collection of reports has been successful.

NO
NodeMCU port Gnd Gnd

III. 1. Result of tool realization
The following are the results of the tool realization. Fig. 7 is the result of realizing the Tool. Components of the tool will be described by numbering as follows; 1. An arduino Mega, 2.LCD, 3. RFID, 4. NodeMCU, 5. relay, 6. ESP32 Cam, 7. UV lamp, 8. Solenoid door lock, 9. RFID tag and card. How to use this tool is as follows.
1. Students put RFID Tags on RFID Sensors. 2. Next, the tool will verify the RFID TAG.

The Selenoid on the tool door will open if the
RFID is verified correctly. At the same time, the ESP32-CAM takes students' photos to be sent to laboratory assistants' Telegram and Google Spreadsheets along with group information and report collection time. 4. Students place the report into the tool. 5. The Selenoid on the door will close after students enter the report within 30 seconds. 6. UV Sterilizer will be on to sterilize report. 7. The tool can be re-used.

III. 2. Tool testing
Testing was done by comparing the tool measurement result that was made with standard tools that were commonly used. In addition, there was testing by taking the results of the actual condition and real-time Calculations were done using several formulas, including. Deviation = (nSensor -nMeasure) (1) which is the deviation formula [16]; which is the average value formula [17]; standard deviation formula [16][18]. and, formula percentage accuracy and percentage error can be expressed below. Table IV indicates the results of ten times 12 Volt power supply testing using a multitester. This Test obtained a deviation of 0.00 and 100% accuracy, and it can be concluded that the voltage of 12 volts used in this tool is accurate. This 12 Volt voltage will be used to activate the solenoid and become a stepdown source to provide supply to the control circuit.   Table V demonstrates the testing of a 5 volts power supply using multi-tester by ten times test and obtained the deviation of 0 volts and 100% accuracy. It can be concluded that the 5 volts voltage used in this tool is accurate.

III.5. Testing of WiFi connection to NodeMCU ESP8266
In table VI, the test results were obtained from ten times WiFi connection to NodeMCU ESP8266 testing with a waiting time of 4 seconds and 5 seconds. The conclusion of the testing is that NodeMCU ESP8266 can be connected to WiFi at medium speed.    Table VII shows testing WiFi connection to ESP32-CAM by ten times. From the testing result, it was obtained the results of connection with a waiting time of 4 seconds and 5 seconds. The conclusion of this testing is WiFi speed connection to ESP32-CAM is medium.

III.6. Testing of Wifi connection to ESP32-CAM
In Table VII, it can be seen that in ten trials of Wifi connection to ESP32-CAM, all of them were successfully connected properly. Connection time is in the range of 4 to 5 seconds. The data transfer rate for all test connections is medium speed.
The results of this test indicate that the Wifi connection has been running normally, so that the built device can be used properly.    Table XII shows the results of ten times Telegram application testing with 3 second waiting time to send notifications. From the testing, the conclusion is that the speed of sending the notification is medium. It can be observed in Table XII that from ten tests, the results obtained are always consistent which indicates that the equipment has worked well.