Tài liệu A smart management system for the computer engineering lab

NATIONAL UNIVERSITY OF HO CHI MINH CITY HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING THESIS A Smart Management System for the Computer Engineering Lab Instructor: Reviewer: Students: Assoc. Prof. Dr. Phạm Quốc Cường Dr. Lê Trọng Nhân Vũ Thành Đạt - 1752169 Trịnh Mai Duy - 1752139 HO CHI MINH CITY, 7/2021 ĈҤ,+Ӑ&48Ӕ&*,$73+&0  75ѬӠ1*ĈҤ,+Ӑ&%È&+.+2$ .+2$.+ .70i\WtQK %Ӝ0Ð1.+07 &Ӝ1*+Ñ$;­+Ӝ,&+Ӫ1*+Ƭ$9,ӊ71$0 ĈӝFOұS7ӵGR+ҥQKSK~F 1+,ӊ09Ө/8Ұ1È17Ӕ71*+,ӊ3 &K~ê6LQKYLrQSK̫LGiQWͥQj\YjR WUDQJQK̭WFͯDE̫QWKX\͇WWUuQK +Ӑ9¬7Ç1 7UӏQK0DL'X\ +Ӑ9¬7Ç1 9NJ7KjQKĈҥW 1*¬1+ .ӻWKXұW0i\WtQK 0669  0669  /Ӟ3&&.70 ĈҫXÿӅOXұQiQ 6PDUW0DQDJHPHQW6\VWHPIRUWKH&RPSXWHU(QJLQHHULQJ/DE 1KLӋPYө\rXFҫXYӅQӝLGXQJYjVӕOLӋXEDQÿҫX 6WXGHQWVQHHGWRSURSRVHDVXLWDEOHVPDUWV\VWHPWRPDQDJHWKH&RPSXWHU (QJLQHHULQJODE 6WXGHQWVQHHGWRLPSOHPHQWWKHSURSRVDOZHOODQGWHVWWKHSURSRVHGV\VWHPVZLWK GLIIHUHQWVFHQDULRV 6WXGHQWVQHHGWRZULWHDFRPSUHKHQVLYHUHSRUWIROORZLQJWKHEDFKHORUWKHVLV WHPSODWHRIWKHXQLYHUVLW\ 1Jj\JLDRQKLӋPYөOXұQiQ  1Jj\KRjQWKjQKQKLӋPYө +ӑWrQJLҧQJYLrQKѭӟQJGүQ  3KDP4XRF&XRQJ   3KҫQKѭӟQJGүQ 1ӝLGXQJYj\rXFҫX/971ÿmÿѭӧFWK{QJTXD%ӝP{Q 1Jj\WKiQJQăP &+Ӫ1+,ӊ0%Ӝ0Ð1 *,Ҧ1*9,Ç1+ѬӞ1*'Ү1&+Ë1+ .êYjJKLU}K͕WrQ .êYjJKLU}K͕WrQ 3+̮1'¬1+&+2.+2$%͠0Ð1 1JѭӡLGX\ӋWFKҩPVѫEӝ ĈѫQYӏ 1Jj\EҧRYӋ ĈLӇPWәQJNӃW 1ѫLOѭXWUӳOXұQiQ TRƯỜNG ĐẠI HỌC BÁCH KHOA KHOA KH & KT MÁY TÍNH CỘNG HÒA XÃ HỘI CHỦ NGHĨA VIỆT NAM Độc lập - Tự do - Hạnh phúc ---------------------------Ngày 07 tháng 8 năm 2021 PHIẾU CHẤM BẢO VỆ LVTN (Dành cho người hướng dẫn) Trịnh Mai Duy – 1752139 – Ngành Kỹ thuật Máy tính Vũ Thành Đạt – 1752169 – Ngành Kỹ thuật Máy tính 2. Đề tài: A Smart Management System for the Computer Engineering Lab 3. Họ tên người hướng dẫn: Phạm Quốc Cường 4. Tổng quát về bản thuyết minh: Số trang: Số chương: Số bảng số liệu Số hình vẽ: Số tài liệu tham khảo: Phần mềm tính toán: Hiện vật (sản phẩm) 5. Tổng quát về các bản vẽ: - Số bản vẽ: Bản A1: Bản A2: Khổ khác: - Số bản vẽ vẽ tay Số bản vẽ trên máy tính: 6. Những ưu điểm chính của LVTN: - Students proposed a suitable smart system to manage the Computer Engineering. - Students implemented the proposal well and tested the proposed systems with different scenarios although they cannot come to the lab for a while due to the pandemic. - The report is adequately written, although some sections need more details explained. 1. Họ và tên SV: 7. Những thiếu sót chính của LVTN: - Students need to improve system by different accessing methods - Students should analyze and compare their system with others 8. Đề nghị: Được bảo vệ o Bổ sung thêm để bảo vệ o Không được bảo vệ o 9. 3 câu hỏi SV phải trả lời trước Hội đồng: a. Can the system prevent wrong objects collected from cabinets after authentication? 10. Đánh giá chung (bằng chữ: giỏi, khá, TB): Điểm: 9.0/10 Ký tên (ghi rõ họ tên) Phạm Quốc Cường TRƯỜNG ĐẠI HỌC BÁCH KHOA KHOA KH & KT MÁY TÍNH CỘNG HÒA XÃ HỘI CHỦ NGHĨA VIỆT NAM Độc lập - Tự do - Hạnh phúc ---------------------------Ngày 12 tháng 08 năm 2021 PHIẾU CHẤM BẢO VỆ LVTN (Dành cho người phản biện) 1. Họ và tên SV: VŨ THÀNH ĐẠT MSSV: 1752169 Ngành (chuyên ngành): Kỹ thuật máy tính Họ và tên SV: TRỊNH MAI DUY MSSV: 1752139 Ngành (chuyên ngành): Kỹ thuật máy tính 2. Đề tài: A Smart Management System for the Computer Engineering Lab 3. Họ tên người phản biện: T.S Lê Trọng Nhân 4. Tổng quát về bản thuyết minh: Số trang: 79 Số chương: 06 Số bảng số liệu: 0 Số hình vẽ: 46 Số tài liệu tham khảo: 10 Phần mềm tính toán: 01 Hiện vật (sản phẩm): 0 5. Tổng quát về các bản vẽ: - Số bản vẽ: Bản A1: - Số bản vẽ vẽ tay Bản A2: Khổ khác: Số bản vẽ trên máy tính: 6. Những ưu điểm chính của LVTN:  In this thesis, a full stack project is designed, proposing for asset management in a lab. The system is based on three different methods for the authentication process, including an RFID Card, a figure print sensor and a keypad for secrete number input.  Students show their great collaboration to integrate the system. Students also prove their capabilities to work with the device drivers, programming in embedded system and also for the web server.  In most interest in the hardware part of this project is the figure print sensor due to its complexity in communication. Moreover, the network protocol in this thesis is also a challenge in a microcontroller system, which is normally fully supported. Finally, is the software implementation of AES encryption, which is the most powerful encrypted algorithm for hardware platform. The demonstration shows that these modules work well and can be inherited for future project. 7. Những thiếu sót chính của LVTN:  The database should be improved. However, it is a minor part in a CE thesis project. 8. Đề nghị: Được bảo vệ  Bổ sung thêm để bảo vệ  Không được bảo vệ  9. 3 câu hỏi SV phải trả lời trước Hội đồng: 1. It is assumed that there is an exception that an RFID card of a student is lost. How does your system handle this use case? 2. In the case a camera is used in your system to increase the security process. How does it integrate in the system? 10. Đánh giá chung (bằng chữ: giỏi, khá, TB): Giỏi Điểm : 9/10 Ký tên (ghi rõ họ tên) TS. Lê Trọng Nhân Declaration We hereby declare that except where specific reference is made to the work of others, the content of this dissertation is original and has not been submitted in whole or in part for consideration for any other degree or qualification anywhere. This dissertation is our own work and contains nothing which is the outcome of work done in collaboration with others, except as specified in the text and Acknowledgements. This dissertation contains fewer than 13000 words including appendices, bibliography and has fewer than 50 figures. Due to the COVID-19 pandemic, we weren’t able to include images of our final product in this dissertation. No live demonstration was carried out to showcase our work and research. Acknowledgements We would like to acknowledge the involvement and guidance of our instructor, Dr. Phạm Quốc Cường, our reviewer, Dr. Lê Trọng Nhân as well as the help from our friends and classmates in the faculty of Computer Science & Engineering. Their tremendous support provided us with extra knowledge and helped us complete this dissertation to the best of our ability. We would also like to thank all the research papers and technologies for inspiring us on many portions of the our design. A special thank to Trí, An and Dũng. Table of content I. INTRODUCTION 1 II. THEORETICAL FRAMEWORK 2 1 RFID Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Fingerprint Identification Technology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 Literature Review and Commercial Products . . . . . . . . . . . . . . . . . . . . 4 4 Components and Hardware Preparation . . . . . . . . . . . . . . . . . . . . . . . 8 III. SYSTEM DESIGN 1 Logical Diagram Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2 Server Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3 Application Level: Creating a User Interface . . . . . . . . . . . . . . . . . . . . . 21 4 Hardware Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4.1 Authentication Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4.2 Storage Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.3 Microcontroller Configuration . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.4 Complete Datasheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5 Determining fingerprint ownership . . . . . . . . . . . . . . . . . . . . . . . . . . 39 6 Data Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 7 Data Encryption over TCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 IV. SYSTEM IMPLEMENTATION V. 17 42 1 Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2 Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 3 User Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 4 Hardware Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 5 Administrative Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 TESTING & EVALUATION VI. CONCLUSION 53 72 List of figures and images 1 A complete RFID scanning system . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Minutiae features on a fingerprint . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3 A supply chain model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 X-NUCLEO-H743ZI2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 3x4 keypad and its circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 3x4 keypad’s matrix circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 PN532 NFC HAT RFID module . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 9 Common RFID tag form factors . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 10 Adhesive RFID tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 11 R503 Fingerprint Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 12 SSD-1106 OLED Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 13 LY-03 12VDC Solenoid Door Lock . . . . . . . . . . . . . . . . . . . . . . . . . . 14 14 MA1208 Electric Cabinet Security Lock . . . . . . . . . . . . . . . . . . . . . . . 14 15 4-relay Opto-isolator Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 16 DC-DC Buck Boost Converter with LCD Display . . . . . . . . . . . . . . . . . . 15 17 DSL-2730u Wireless Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 18 Full Layout of the Smartlab System . . . . . . . . . . . . . . . . . . . . . . . . . 17 19 System login page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 20 System UI structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 21 The welcome tab with Bootstrap’s Jumbotron . . . . . . . . . . . . . . . . . . . . 24 22 A notification example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 23 A modal example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 24 The tab Users with DataTables formatting . . . . . . . . . . . . . . . . . . . . . 25 26 The Users tab on a 580 pixel-wide smartphone screen . . . . . . . . . . . . . . . 26 27 Authentication Module Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 28 R503 processing procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 29 Storage Module Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 30 The cabinet interior with the MCU. . . . . . . . . . . . . . . . . . . . . . . . . . 31 31 Three possible I2C wiring options . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 32 Event Signals usage example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 33 Message queue model example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 34 Hardware level datasheet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 35 Fingerprint data mapping across the system . . . . . . . . . . . . . . . . . . . . . 39 36 System TCP message format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 37 An encryption and decryption process, simplified . . . . . . . . . . . . . . . . . . 41 38 AES-ECB encryption block scheme . . . . . . . . . . . . . . . . . . . . . . . . . . 41 39 Entrance Authentication Use-case Diagram . . . . . . . . . . . . . . . . . . . . . 43 40 Request modal form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 41 The Hardware tab on the web UI . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 42 The Management tab for hardware . . . . . . . . . . . . . . . . . . . . . . . . . . 47 43 Hardware Request activity flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 44 Hardware Return activity flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 45 The Command tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 46 The Event log tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING I. INTRODUCTION Motivation As Computer Engineering students, hardware projects have always fascinated us since freshman year. We’ve had opportunities to get our hands on different hardware throughout many courses. Some of which have lab hours and require us to attend the computer hardware lab. Seeing the current state of how the lab has been managed, we couldn’t help but ask ourselves what can be done to improve the room’s role for both teachers and students. With all the knowledge we’ve accumulated during 4 years of studying, this thesis is the perfect chance allowing us to solve this problem. That is our inspiration to choose A Smart Management System for the Computer Engineering Lab as our thesis project. Scope This paper will investigate and review some similar existing researches and cover our development progress of the smart inventory management system. The development progress includes: adoption from other researches and papers, hardware preparation for the project, system design, development, testing & evaluation. Outcomes The primary outcome of this project is to propose a viable upgrade solution for traditional hardware laboratories in some facilities or universities that may lack a proper inventory management instrument by using an automated computer system. For us students personally, we hope that this project can teach us a lot about team working, improve our researching knowledge and reinforce our coding skill across hardware and software platforms. Computer Engineering Thesis - Semester 202 1/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING II. 1 THEORETICAL FRAMEWORK RFID Technology Radio-frequency identification (RFID) is a wireless sensor technology used in tracking and identifying tags attached to objects by using electromagnetic field without human intervention. Data is sent and received with a system consisting of RFID tags, an antenna, an RFID reader, and a transceiver. Unlike a barcode, reading an RFID tag must be within a distance of the antenna but doesn’t require it to be within a reader’s line of sight. The tag therefore can be embedded in any object. Application of RFID: Asset Tracking, Supply Chain Management, Retailing, Security and Access Control, etc. Figure 1: A complete RFID scanning system There are two different types of RFID tags: • Active tags have an internal battery source which allows them to continuously broadcast their signal at a longer range but they are more expensive and the lifespan depends on the power source longevity. Active tags are best used for real-time tracking. • Passive tags have no power source and rely directly on an RFID reader’s power source. Opposed to active tags, they has no internal battery, making them much lighter, cheaper and they can operate indefinitely, with the down side of having a much shorter read range. Passive tags are best used in access control applications, labeling, asset tracking. Computer Engineering Thesis - Semester 202 2/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING 2 Fingerprint Identification Technology Fingerprint is one of the most well-known biometric authentication methods. Due to their uniqueness and consistency over time, fingerprints have been used for identification for decades. Thanks to computer advancements, fingerprint ID gets more popular due to ease of acquisition and their usage is well established in many fields including law enforcement, immigration and basic electronic login authentication. There are two main matching techniques: minutiae-based matching and pattern matching. Pattern matching is used to find duplicates of the same fingerprint based on print images. The most commonly used technique, minutiae-based, relies on the minutiae features of a fingerprint, which are considered the most discriminating and reliable features on a human finger. They have become the basis for computer fingerprint authentication and are still extensively studied in the context of pattern recognition and image processing. Figure 2: Minutiae features on a fingerprint Computer Engineering Thesis - Semester 202 3/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING 3 Literature Review and Commercial Products  Library Management Systems A library management system shares a lot of resemblance with our system. We take a quick look on how one such system works and see what we can adopt for our project. In this system [1], the library books are uniquely tagged with RFID. An RFID reader will read data off the tag and perform an issue/reissue/return process, whatever action the librarian needs. The detailed information including book name, author(s), etc. are all stored in a database. That information is said to be associated with an RFID tag. Similarly, RFID tags are also issued to library users. A user’s tag UID when searched on the database will reveal their name, address, phone number , etc. A user can issue a book without any human intervention. They scan their RFID to let the system knows who they are. Then each issued book is scanned and gets picked up by the software. The process is finished and the system acknowledges this by recording it in the database. If a user wishes to return a book, they can simply once again scan its RFID tag, and the system will update the book status in the database. To control the system, a user interface is extensively provided via a Windows software, a web application and an Android application. Computer Engineering Thesis - Semester 202 4/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING  Amazon Hub Apartment Locker This is a package management service aimed at apartment complexes, where it can help landlords or building management to free up their time concerning of their residents’ deliveries. The residents can pick up their packages any time they want. The company also places a lot of other lockers at high accessibility and high traffic neighborhood locations [2], usually within delivery routes. The procedure as explained by Amazon: 1. A resident places an order to their building. 2. Once the package arrives, they get a pickup code or a barcode through email or SMS. 3. At the locker, the resident enters their code they received earlier. 4. The cabinet containing their package will open for pickup. Computer Engineering Thesis - Semester 202 5/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING  Palex Medical’s Dyane SmartCabinet This product is aimed at hospitals or medical facilities. It helps with management of highcost material or material with high patient traceability requirements. The system provides live product traceability and movement. It keeps an eye on the inventory by tracking, eliminating and replacing expired products. Supplies are always available at the right time with protocols in case of emergency. The system can also identify people who access the cabinet, what they remove or replace in the inventory and the intended patient whom the material is used for. Management software that comes along provides data for strategic decision-making, provides annual report and accurate real-time information on the use of high-cost products. The UI touch screen is attached right on the cabinet. It is ’user-intuitive and quick to learn’. Many similar researches also study the use of a smart cabinet in healthcare [3] [4]. Computer Engineering Thesis - Semester 202 6/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING  Supply Chain Automation with RFID Figure 3: A supply chain model The supply chain is a complex multi-process network involving individuals, companies, organizations and resources in the creation and sale of a product. This network spans from procurement of raw materials to the manufacturing process and then distribution to warehouses and retailers. Nearly most, if not all services have a supply chain and their complexity varies greatly depending on the industry. To assist people involved in supply chains, many companies enlist the addition of IT infrastructure to help track and control their inventory across all levels of production using RFID technology [7]: • Manufacturer sites: Products and even the cases and pallets carrying those products are identified, tracked, counted. As they exit the site, a reader has all information of the products and they can be traced back to source in the future if a defect is found or shipments are delivered to incorrect addresses. • Distribution centers: RFID helps with the management of yard activities, including transportation, containers and the loading of assets to loading docks. Inspection process can be skipped and packages can be loaded immediately, headed to retail. • Retailers: Items are automatically updated and located in the system accurately and costefficiently. • Pallets, crates and other packaging materials have better re-usability as they are tracked through the whole supply chain. Thanks to RFID, cooperation and communication between parties greatly increase while manual labor decreases on all levels. Overstocking can be no longer be a problem and supply can better match consumers’ demand. RFID helps prevent theft and fraud, making reliable tracking even more important than ever. Computer Engineering Thesis - Semester 202 7/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING 4 Components and Hardware Preparation  Microcontroller The very first option that came to our mind was the ESP-32. This is one of the most used Wi-Fi modules in the market and it supports many programming languages. As the system was gradually designed and the scale got larger, we found the ESP-32 is no longer capable due to the lack of pinouts and communication channels. We required a better microcontroller to work with. The primary hardware platform we’ve chosen for this project is the NUCLEO-H743ZI2 by STMicroelectronics (abbreviated ST). ST offers a large collection of embedded hardware series and the H7 is one of the high performance series in their microcontroller portfolio. Other than ST, there are many other manufacturer options worth noting. Arduino for example, was an obvious choice due to their popularity in education environments. There’s also products from Raspberry Pi, NXP, Microchip, etc. But eventually we chose an MCU line we’ve already had experience over, saving us a lot of time. Figure 4: X-NUCLEO-H743ZI2 For this particular project, we’re going to use: • All four I2C channels. • Two UART channels. • Ethernet PHY with LWIP middleware. • FreeRTOS for resource management. Computer Engineering Thesis - Semester 202 8/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING • Hardware-based timers. • Dozens of GPIO pins to power LEDs, buttons, inputting/outputting signals. • 5V and 3.3V power delivery for external peripherals. MCU Clock speed Memory GPIO Pins I 2 C Channels UART Channels Built-in Ethernet Timer interrupt Nucleo H743ZI2 480MHz 1MB 168 4 9 YES YES ESP-32 240MHz 520KB 34 2 3 NO YES Hardware specification comparison between Nucleo H743ZI2 and ESP-32  Membrane Keypad The keypad is a matrix of electrical switches. Each switch in a row is connected to other switches in the same row by a conductive trace underneath the pad. The same idea applies for every switch in a column. There are 7 pins in total with 4 row pins and 3 column pins. Figure 5: 3x4 keypad and its circuit Computer Engineering Thesis - Semester 202 9/72 HO CHI MINH UNIVERSITY OF TECHNOLOGY FACULTY OF COMPUTER SCIENCE AND ENGINEERING The working principle is very simple. Pressing a button shorts one of the row lines to one of the column lines, allowing current to flow between them. For example, when key ‘7’ is pressed, column 1 and row 3 are shorted. Figure 6: 3x4 keypad’s matrix circuit However a signal is interpreted on the MCU is up to the programmers, since at core they are just switches.  PN532 NFC HAT This RFID chip is compatible with many other hardware platforms: Raspberry Pi, Arduino etc. in addition to STM32. The frequency of operation is 13.56MHz, supporting all Mi-fare compatible cards. It offers three different communication protocols: UART, SPI, I2C. Figure 7: PN532 NFC HAT RFID module Computer Engineering Thesis - Semester 202 10/72