ECE 477 Digital Systems Senior Design Project Rev 8/12

ECE 477 Digital Systems Senior Design Project Rev 8/12 Homework 3: Design Constraint Analysis and Component Selection Rationale

Team Code Name: ____ MyATM ______Group No. ___ 5 __ Team Member Completing This Homework: ____ Tung Lun Loo ______E-mail Address of Team Member: _____ tloo @ purdue.edu

Evaluation:

SEC DESCRIPTION MAX SCORE 1.0 Introduction (including updated PSSC) 10 2.0 Design Constraint Analysis - 2.1 Computational Requirements 10 2.2 Interface Requirements 5 2.3 On-Chip Peripheral Requirements 10 2.4 Off-Chip Peripheral Requirements 5 2.5 Power Constraints 5 2.6 Packaging Constraints 5 2.7 Cost Constraints 5 3.0 Component Selection Rationale 20 4.0 Summary 5 5.0 List of References 10 App A Parts List Spreadsheet 5 App B Updated Block Diagram 5 TOTAL 100

Comments: Comments from the grader will be inserted here. ECE 477 Digital Systems Senior Design Project Rev 8/12

1.0 Introduction An automated teller machine (ATM) is a computerized device that let users perform financial transactions without the presence of a bank or a cashier. MyATM is another ATM that supports the basic ATM functionalities with enhanced security. It first detects a user’s presence with an occupancy sensor, reads the identity of the user from his/her cash card, verifies the identity of the user, and then updates the user’s account information in cash card once the transaction is done. With improved security system in mind, myATM features face recognition authentication technology (FRAT) along with Personal Identity Number (PIN) authentication. FRAT in myATM is used to login to the user’s account, with PIN number acting as the second layer of account protection. Besides, myATM also features a graphical user interface that has better user interactivity. MyATM user can use touchpad that supports gestures to navigate myATM’s menu and select desired operations to speed up the transaction process. MyATM machine are made out of eight main components. They are the PIC18F24J11 microcontroller, Intel Atom Board, 2 web cameras, RFID Reader and Writer, Occupancy Sensor, Speaker, Touchpad, and Keypads. The biggest constraints and challenges of building myATM are the face recognition algorithm’s processing speed and accuracy. When user’s presence is detected via the occupancy sensor, the microcontroller will signal the Atom processor to start capturing face images and processing them. The image processing process should be less than a few seconds so that the login process is quick. Another constraint comes from the process of updating the cash card information to the server. The cash card should be able to be read, written, and updated. Power and portability are not the major constraint of the design since the ATM machine will be on-station. Below are the PSSCs of the project: 1. An ability to use face recognition to verify the identity of the user 2. An ability to use touchpad to recognize gestures for menu navigation. 3. An ability to sense the presence of a user in front of ATM. 4. An ability to update the value in a cash card. 5. An ability to use keypad to input numbers for PIN validation and transaction purposes.

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2.0 Design Constraint Analysis There are several constraints to be considered when selecting components for myATM. To make the device feasible and comparable with current ATM systems, it has to be cheaper than the current ATM machine. To enhance the security and not delaying the login process, myATM needs to be able to fetch, compute and compare user images in a short time (Thus the processing power of the motherboard is important). The microcontroller needs to have UART interface to communicate with our motherboard, timers for sampling purposes and enough I/O pins for keypad, PIR sensor, and RFID reader and writer.

2.1 Computation Requirements The computational tasks are mostly handled by our motherboard. Those tasks includes  Run responsive GUI on the monitor

 Detect user’s input from touchpad

 Communicate with microcontroller via COM port (RS232)

 Receive RFID data, occupancy sensor output and keypad input from microcontroller

 Capture multiple images frames using webcam

 Process the images through face recognition algorithm

 Upload the user cash card data to the server

 Output sound through audio jack Based on the amount of tasks and the need of speed for the applications, the board needs to have a processing speed of around 1.6GHz, 512MB RAM and supports hyper-threading technology for parallel computing. We have tested a sample face recognition application and clarified the requirement using Intel Atom N270 motherboard. To utilize OpenCV libraries, plenty of RAM and storage will also be needed. In order to output a smooth and clear GUI on the monitor, the screen will need to be refreshed at least 60Hz with a minimum resolution of 640x480. For the purpose of supporting three RGB true colors in face recognition, the webcam needs to have at least 24 bits pixel quality. The images taken need to be transferred to the motherboard at no less than 210Mb/s to acquire multiple frames in a short time. Another requirement of the processing unit is to have a way to communicate with the microcontroller. A

-3- ECE 477 Digital Systems Senior Design Project Rev 8/12 bidirectional serial port (in this case, UART to RS232) with a transfer rate of up to 115Kbps will be sufficient for the transferring purpose. 2.2 Interface Requirements The microcontroller will be communicating with the Atom Board using a serial port interface. Thus, a RS232 to UART adaptor will be used. The microcontroller needs to have at least 13 digital input output pins. 7 digital I/O pins are used to sample the keypad inputs, 1 digital I/O pin is used on the PIR motion sensor, 3 digital I/O pins on the RFID Read Write Chip and a few indicator LEDs for debugging purposes [7] [8] [9]. The Atom Board needs to support VGA connection for the monitor, RS232 for microcontroller, 3 USB ports for 2 cameras and a touchpad, Ethernet for the server connection, and audio jack for the speaker.

2.3 On-Chip Peripheral Requirements The microcontroller needs to have at least 3 timers for RFID data, keypad inputs and PIR motion sensor. The first timer channel is required to sample the incoming RFID data from RFID cash card to microcontroller at every fixed interval. Since the RFID card reading and writing operation are not performed at the same time, the same timer can be used to write RFID data from the microcontroller to the RFID transponder (cash card). The second timer channel is used to sample the keypad inputs while the third timer is used to sample the pulses from the occupancy sensor at certain intervals to determine the presence of user in front of myATM. Besides, a UART interface is required for microcontroller to communicate with the Intel Atom Development Board. Input signals from the keypad will be transmitted to the microcontroller and then to the Atom board so that the system can validate user-input PIN. In addition, user profile data will be received and transmitted via RFID interface. After that, it will be sent to microcontroller and then to the motherboard via UART to be further updated in the server. In short, the microcontroller in myATM needs at least 3 channels of 8-bit or 16-bit timers and a UART interface.

2.4 Off-Chip Peripheral Requirements

The off-chip peripheral required are an RFID base reader and writer, a RS-232 level translator and a 5V to 3.3V level translator. The RFID base reader and writer chip is used to read and write to the RFID tag. The IC needs to be able to be configured dynamically using microcontroller to read from or write on an RFID tag. The RS-232 level translator translates UART signals to RS-232 signals to communicate with the Atom Board. On the other hand, 5V to 3.3V level translator is used for sending signals to RFID base reader and writer by the microcontroller since the microcontroller runs on 3.3V logic and the RFID base reader and writer runs on 5V logic. [9]

2.5 Power Constraints Since the project is an on-station device, minimal power consumption is a plus point but not a necessity. We will acquire A.C power to power the Intel Atom Board, LCD monitor screen, and the custom-made PCB. Therefore, it is not a portable device and it has to be available only in place where A.C power is accessible.

2.6 Packaging Constraints The packaging will need to be tough and able to fit the parts reasonably. Therefore we are looking at using wood casing to put our electronics part. Considering the fact that the standard ATMs are 56” Height [1], we are implementing the same height for standard adults. The stereo cameras will be placed at a height of 53” where it should be able to capture the user’s face.

2.7 Cost Constraints The current ATM machines are priced at approximately $1800 [1]. Considering the fact that the ATMs on the market include robust cover, printer, cash locker and cash dispensing part, the price is no doubt higher. Therefore, we are targeting below $500 for our electronic design so that we have another $1300 for the implementation of covers.

3.0 Component Selection Rationale The microcontroller choices are narrowed down to PIC and ATmega due to the project constraints, availability of development board, and familiarity of the microcontroller

-5- ECE 477 Digital Systems Senior Design Project Rev 8/12 environment. Initially we choose the PIC32MX110F016D [2] microcontroller because it supports full speed USB 2.0 connection to interface with the motherboard. However, after gathering feedbacks from our design constraint presentation, we decided to go with serial communication interface instead of USB interface. Thus, our choices revolve around PIC18F24J11 and AT90PWM2B. PIC18F24J11[3] has 28 pins, three 16-bits timer, and two enhanced USART modules that support RS-232. On the other hand, AT90PWM2B[4] features 24 pins, three 8-bit timers, and supports UART. Thus, they have fulfilled the requirements for the design, which is 3 timers, support UART, and have more than 13 digital I/O pins. We decided to choose PIC18F24J11 because the TAs suggested that PIC microcontrollers have less problems in external circuitry compared to other microcontroller families. There are many options our group has considered for the single board computers such as Intel Atom Board, Beagle Board, and Raspberry Pi. Raspberry Pi is not available to be delivered in a short time so it is eliminated from our options. We are looking at choosing between Intel Atom N270 and BeagleBoard-xM. Atom N270 features single core Atom processor running 1.6GHz, 512MB RAM, supports Hyper-Threading Technology, have 3 USB ports, 10/100 Ethernet, RS232 and VGA [5] while BeagleBoard-xM runs ARM Cortex A8 at 1GHz, 512MB RAM, 4 USB port, DVI, 10/100 Ethernet and RS232 [6]. Between Intel Atom Family and ARM Boards, Atom is more preferable because x86 instructions works better with most Linux Distro compared to ARM architecture. We choose to install Linux is because it is open source and supports a lot of face recognition libraries. Since Atom N270 is readily available in lab, we were given the board to test available face recognition algorithms. Since it works with the sample programs without much lags, we decided to stick with the Intel Atom N270 for our project.

4.0 Summary There are many design constraints in myATM that need to be considered when making a decision on parts. The focus on security instead of mobility in the design leads us to a direction of choosing high processing power development board instead of low power consumption parts. The microcontroller is used more on fetching user inputs such as RFID card info, keypad inputs, and occupancy sensor output. Thus adequate pin counts (13), features and peripherals are needed for our microcontroller. We have chosen Intel Atom N270 for the processing power and RAM for the face recognition algorithm and PIC18F24J11 microcontroller for the simplicity, price and

-6- ECE 477 Digital Systems Senior Design Project Rev 8/12 matching of our constraints. We believe our design will make full use of the parts we choose instead of over killing or under powering the parts.

5.0 List of References

[1] EmpireATM, “Our Products: ATM Machines”, 2013, [Online]. Available: http://empireatms.com/products.html

[2] MicroChip, “PIC32MX1XX/2XX”, 2009, [Datasheet]. Available: http://www.mouser.com/ds/2/268/61168D-78803.pdf

[3] MicroChip, “PIC18F2XJxx Family”, 2009, [Datasheet]. Available: http://www.mouser.com/ds/2/268/39687e-62060.pdf

[4] ATMEL, “8-bit AVR Microcontroller with 8K Bytes In System Programmable Flash”, 2010, [Datasheet]. Available: http://www.mouser.com/ds/2/36/doc4317-46744.pdf

[5] Intel, “Intel Atom Processor N270”, [Online]. Available: http://ark.intel.com/products/36331/Intel-Atom-Processor-N270-512K-Cache-1_60-GHz- 533-MHz-FSB#iid=2524

[6] BeagleBoard, “BeagleBoard-xM Product Detail”, Jun 01, 2011, [Online]. Available: http://beagleboard.org/hardware-xM

[7] Keypad, “SERIES 96 Conductive Rubber”, 2010, [Online]. Available: http://media.digikey.com/pdf/Data%20Sheets/Grayhill%20PDFs/96%20Series.pdf

[8] PIR sensor, “EKMC Standard Profile (170 uA)”, 2009, [Online]. Available: http://pewa.panasonic.com/assets/pcsd/catalog/papirs-ekmc-catalog.pdf

[9] RFID Base Station, “Communicating with RFID Base Station”, 2009, [Online]. Available: http://www.ti.com/lit/an/swra283/swra283.pdf

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Appendix A: Parts List Spreadsheet

Vendor Manufacturer Part No. Descriptio Unit Cost Q Total Cost n Digi-Key Microchip PIC18F24J11-I/SO Microcontr 2.94 $2.94 oller Digi-Key Grayhill Inc 96AB2-102-F 4x3 14.20 $14.20 keypad Digi-Key Atmel U2270B-MFPY RFID R/W 3.01 $3.01 base station Digi-Key Atmel ATA5577M1330C-PP RFID 3.44 $3.44 transponde r/tag Digi-Key Panasonic EKMC1601112 PIR 10.26 $10.26 motion sensor Amazon Ergonomic The Ergonomic USB 36.95 $36.95 Touchpad Touchpad touchpad Mouser Maxim Integrated MAX3373EEKA+T 5V to 3.3V 2.30 $2.30 voltage level translator Mouser Texas LM2675M-5.0/NOPB 5V, 1A 3.60 $3.60 Instruments switching regulator Mouser Texas LM2675M-3.3/NOPB 3.3V, 1A 3.60 $3.60 Instruments switching regulator Mouser Maxim Integrated MAX3232CAE+ RS-232 4.62 $4.62 level translator Amazon Logitech 960-000162 Logitech 7.23 14.46

QuickCam Messenger TOTAL $99.38

Appendix B: Updated Block Diagram