Liquid Crystal display (LCD) 1 Register Select (RS) 1 Enable (EN) 4 Digital pin outputs to interface with the LCD Digital I/O pins Red, Green, Blue Light emitting diode matrix 1 Serial clock (CLK) 1 Chip select (CS1) 1 Master output, input (MOSI) SPI I/O pins Hall effect sensor matrix 1 Serial (CLK) 1 Chip select (CS2) 1 Master output, slave input (MOSI) 1 Analog SPI I/O pins Analog read pin Wireless data transmission device 1 Transmit pin 1 Receive pin UART I/O pins XY grid stepper motors 4 direction control Digital output pins Electromagnet 1 Enabler 1 Potentiometer control Digital I/O pin PWM pin Audio-Sound Module 1 Serial clock (CLK) 1 Chip select (CS3) 1 Master output, input (MOSI) 1 Master input, slave output (MISO) SPI I/O pins With all the features of the microcontroller obtained, a comparison of the three microcontrollers is shown in Table 7: Table 7 – Comparing the three microcontrollers in order to make a final decision. PIC18F46K80 MSP430FR5739 Atmel Corporation ATmega 2560 Operating voltage 1.8 - 5.5 2 - 3.6 2.7 - 5.5 V Digital I/O pins 35 33 54 Anlaog input pins 11 14 16 UART & SPI busses 3 3 4 Program memory 64 KB 16 KB 256KB Clock speed 64 MHz 24 MHz 16 MHz Experience with product None None Very experienced Price per microcontroller $4.30 $6.35 $17.97 Price per development board $165.00 $29.00 $58.95
unit of magnetic field distance. Since electromagnet diameter is 3.175cm, our magnetic field distance will be approximately 0.95cm. Due to the fact that we also had magnets on the top of the chess board our magnetic field distance will be bigger than 0.95 cm. The EM 137 Electromagnet Company “APW Company” was our second choice. This electromagnet has 3.47cm diameter and 33-44lb holding value. The voltage supply for this magnet is 12V. Also it has standard thru hole mounting and includes brackets to hold it in place. Our last choice was ER2-103 Electromagnet Company “Industrial Magnetic Inc.” The magnet has the same diameter as our previous two choices. Different voltage supply 24 V and smaller holding force value. This electromagnet also is twice as expensive as another two electromagnets. We found during our research that there are not many companies that are selling small, powerful and cheap electromagnets. We think the reason is that not many DIY projects involved small and strong electromagnets. But on the other hand there are a lot of inquiries on the Internet from people about how to create electromagnets at home. A comparison of the electromagnet types is made in Table 10. 10 - Electromagnet Specification Comparison Model of electromagnet R-1207-12 EM 137 ER2-103 Voltage, V 12 12 24 Current DC DC DC Duty Continuous Continuous Continuous Watts 3.3 5 4.2 Amps 0.28 0.41 n/a Holding Force, Lbs 45 33 22 Weight, Lbs 0.24 0.24 0.4 Diameter, cm 3.175 3.493 3.175 Height, cm 1.905 2.06 n/a $ 40 29.24 76.06 The size of the positioning system is also one of the important factors for us. We didn’t want to create big and bulky chess board. Based on specifications boards have approximate size of not bigger than 70cm by 70cm and height of a board should not exceed 30cm. Based on this data we need to choose optimal size and strength of the motors. In addition to the electromagnet we need to choose some magnets needed to be installed into chess pieces. After some research, we realized that there are many places
Pass Lost Username Email containing reset key Request a key for a user who has lost their password Pass Reset UserID Reset Key (Success) Success Code (Failure) Error Code Error Message Choose a new password for the user Add UserID Key GameID (Success) Success Code (Failure) Error Code Message Add a user to a game as an observer. The management page requested by both the physical chess board as well as the web interface will be the log in page. The log in page takes as input a POST request from a web client with the parameters to include a plaintext username and a SHA-1 hash of that user's password. It will take the plaintext username and apply a SHA-1 hash to it as well before concatenating the result with the password's hash. The salted password hash is then hashed once again with SHA-1. The resulting string is compared to the contents of the user's password as it is stored in the users table of the database. If it matches, a response is created containing the user's user id number and an authentication key that must be resubmitted with each other request. This authentication key is concatenated with the user's remote IP address and is then hashed and stored in the table. Further requests to management pages must submit the authentication key correctly and be coming from the same IP address, or else the management page being requested will return a status code 403 - Forbidden error. The system cannot use the more standard method of storing authentication via client-side cookie relating to server-side sessions because the chess board is incapable of storing cookies.
Table 32 – Bill of Materials for development stage. Item Distributor Part Num. Quantity Total Price Arduino Atmega 2560 Sparkfun DEV-11061 1 $58.95 WiFly GSX Sparkfun 1 $84.95 Neodymium magnets Amazon B001ANVAHI 1 (pack of 100) $4.59 16x2 LCD display Donated by team member LM1602C 1 $0.00 Stepper motors Sparkfun ROB-09238 2 $29.90 Rack Gearbox Bracket (2-pack) Vexrobotics 275-1188 1 $9.99 Advanced Gear Kit Vexrobotics 276-2184 1 $19.99 Amico Electromagnet Amazon B005F79TIW 1 $6.82 Sparkle power supply Newegg N82E16817103064 1 $37.99 MP3 Player shield Sparkfun DEV-10628 1 $39.95 Stepper motor driver Pololu 1183 2 $39.90 Analog multiplexer Analog ADG406BNZ 4 $6.60 Allegro Hall Effect Sensor Digikey A1360LKTTN-T 117 $281.43 registers Digikey 296-14857-1-ND 10 $4.94 RGB LEDs Sparkfun 1 (pack of 100) $59.95 Custom PC functioning as server Donated by team member None 1 $0.00 Server OS Donated by team member None 1 $0.00 Visual Studio 10 Donated by team member None 1 $0.00 SQL Server Browser Donated by team member None 1 $0.00 Chrome Developer Toold Google Inc. None 1 $0.00 Total price without tax or shipping $692.36