ECE 411Digital Pong

Maisee Brown

Chris AndrewsHoang Nguyen Omar Alattar

WHAT IS IT, WHAT DOES IT DO? A machine that allows two players to play the game

of pong One player begins the game by triggering the IR

sensor adjacent to a row on the LED matrix which causes a “ball” of light to launch towards the opposite side

The opposing player triggers the IR sensor corresponding to the same row to nullify the “attack” then responds by launching his own ball

If a player is unable to “block” an oncoming ball, the other player receives a point

As the game goes on, it increases in difficulty by increasing the ball speed more and more, requiring quicker reaction times from both players

The game ends when one player’s score reaches 9

INTERFACE Two players communicate with the

device by triggering one of the three IR sensors situated at their respective end of the board

Two 7-segment displays on the front of the board display the current score, the one on the right for player 1 and the one on the left for player 2.

The 5 x 16 LED matrix on the top is the game play interface; it displays the “ball” and scoring and game messages

HOW DOES IT WORK

RATIONALE Fulfill project requirements Simple

Feasible in terms of knowledge Feasible in terms of time

Interesting Exciting Captivating Easy to use, intuitive

Adequately demonstrate our team’s skill at engineering

The objective of our project was a working prototype

HOW WE DID ITApproach

Design

Implementation

Testing

APPROACH Concurrently Worked on Software and

Hardware Built small prototypes at every step to

verify each piece of the design Ran software to insure we could

interface each component the way we expected

Fully prototyped before sending layout

INFRA RED DETECTION ARRAY

Player 2 Signal Interrupt

Player 1IR emitter

Player 2IR Detector

Player 2IR emitter

Player 2IR Detector

Player 1 Signal Interrupt

REQUIREMENTS SPECIFIC TO INPUTS

Must have an interface between the player and machine that is without wires or buttons during play mode.

Must be playable indoors with respect to signal interference.

Motivation for choosing IR technology:• Provides novel and intuitive

interface between player and Pong board

• Provides a “wireless” feel without wireless interfacing

SPECTRUM CONSIDERATIONS

Source: www.mtholyoke.edu/~mpeterso/classes/phys301/projects2001/awgachor/awgachor.htm

• Fluorescent and halogen lights have a reduced spectrum emission at 950nm

IR DETECTOR CIRCUITVERY SIMPLE, BUT ADEQUATE

HARDWARE DESIGN

Hoang Nguyen

DESIGN- SCHEMATIC

DESIGN – VOLATGE SUPPLY

DESIGN - INPUT

ATMEGA32

INT0

INT1IR

SIGNALS

IR SIGNA

LS

OR GAT

E

OR GAT

E

PC 0 1 2

PA 0 1 2

DESIGN - OUTPUT

DESIGN - PCB LAYOUT

SOFTWARE DESIGN

Maisee Brown

SOFTWARE- CONTROLLING THE LED MATRIX

Use SPI interface clock serial data into shift register

Shift Register acts as a serial to parallel converter

Use decoder to select row to be on Lights were the row is selected and there is a

0 from the shift register will be on To scroll you just << the data word you are

sending to the SPI and re-send

CONTROLLING THE LED MATRIX

Cannot light multiple columns at the same time

To write a message:Combine multiple lettersSelect each row very quicklyAppears to human eyes all lights are on

Load data1 into shift regSelect row one

Load data 2 into shift regSelect row two…

MAIN Only flashes through the rows one at a

time and shifts data words out to the shift registers

INTERRUPT SERVICE ROUTINEFLOW CHART

TIMER INTERRUPT ROUTINE

HOUSINGChris Andrews

HOUSING

Requirements Must be assembled using materials, skills, and tools available. Should have an attractive physical case.

Other considerations that guided housing design Must provide mounting and shielding (physical and EM) for IR arrays. Must hold LED matrix and 7 segment displays for easy viewing Must have components accessible for inspection and rework

CABLES: A NON-TRIVIAL DESIGN CHOICE

If you must use cables… Connect components with headers and bus cables Label and document all connections Account for the physical space of the cable in the housing design

Many bugs traced to cabling problems and last minute design changes traced to cabling problems.

TESTINGOmar Alattar

TESTING Modular testing

Shift register testBCD to 7 segment testMicrocontroller testPower system testOR gate interrupt test3-8 decoder test IR function test

Incremental/concurrent testing Integration testing Criteria for knowing our project worked

Power Supply Test

Micro-Controller Test

3-8 Decoder Test

BCD-7 Segment

Decoder Test

Shift Register Test

OR Gate Interrupt

Test

IR Test

Integration Test 1

Setup: Solder capacitors 3 and 5(.01 uF) , IC3 and 4 (74HCT4511D,652), and SV4 and 5 to the board. Plug two seven segment LED's into SV4 and SV5

Step Action Expected Result

Pass

Fail

N/A

Comments

1 Plug AVR programmer into ISB header pins

X

2 Open Pong_BCDTest X

3

Progam the board and watch both 7- segment displays

Both 7 segments should run through the numbers 0-9

X

Overall test Result: X BCD - 7 and 7 segment displays functional

LESSONS LEARNED

Omar

Chris

Hoang

Maisee

THINGS WE WOULD HAVE DONE DIFFERENTLY Add light to show whose turn it is Add buffer to IR circuit Perhaps use capacitive buttons Perhaps implement a real pong where

the position of the paddle is controlled by IR sensors detecting the position of a player’s finger