Virtual Basketball: How Well Do You Shoot

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(No Transcript)
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Virtual Basketball How Well Do You Shoot?

• Chun Li Jingwen Ouyang
• 6.111 Spring 2007

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System Overview
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Accelerometer A/D Converter

• ADXL330 3-axis Accelerometer
• 3g range
• Operating voltage 3V
• 300 mV/g sensitivity

• AD7810 10-bit A/D Converter
• Sample at 1 kHz

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Velocity Position Block Diagram
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Calibration

• Obtain player height
• Calculate initial x, y, z positions
• Why Variances
• 0g bias point
• sensitivity

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Game Display Overview
Initial positions
Initial speeds
10 x 3
10 x 3

labkit_clock
pixel_clock
DCM
To All
Game Logic
Reset Replay
reset_sync replay_sync
Debouncer/ Synchronizer
Ball x, y, z
Shadow
Positions
Positions
10 x 3
10 x 3
pixel_count 10
Display Field
VGA Controller
line_count 10
24 rgb_signal
1 x 4 VGA signals
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Game Logic
Status
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status
ball_x,y,z
10 x 3
Get Ball position (FSM)
Get Shadow Position
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Calculations

• Speed
• Vz g t Vz (only vertical direction has
  acceleration)
  
• t time between each frame
• Position
• X Vx t X
• Y Vy t Y
• X Vz t Z
• 3D to 2D conversion
• W Z X sin(a) Y sin(b)
• U X cos(a) Y cos(b)

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Display Field
3D to 2D Converter
ball_x,y,z
10 x 3
ball_x,y
10 x 3
pixel_count 10
Address Counter For ROM
line_count 10
7 ball_addr
ROM
2 color_index
Color Mapping
rgb_ball
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RGB Controller
24
24 x 4
rgb_signal
rgb signals for the shadow, player, scores, and
background, which are obtained similarly
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Game Display Interface (1)


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4

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Game Display Interface (2)
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Conclusion

• practice shooting without a court
• Whenever
• Game for the Wii