Final Project - Ping Pong Shooter

Goal:
The Ping-Pong shooter, as its name, is able to shoot Ping-Pong balls, and the machine can simulate a real-world situation that if there is a player in front of it, it starts shooting; otherwise, it stops working

Criteria of Success
1. A machine that can shoot
2. Able to control the machine i.e. control weather the ping-pong ball will shoot or not
3. Able to control the system with a laser dependent switch


PERT Chart

How it works:
The ping-pong shooter mainly contains three parts
1. A switch that is depends on a photoresistor and a light source(laser beam)
2. Two DC motors to shoot the balls
3. Stepping mother which acts likae a gate to control the flow of the ball


Main Component

• Photoresistor
• DC motors
• Stepping Motor (a8byj-48)
• Micro controller (89S51)
• Octal high voltage high current Darlington transistor arrays (ULN2803)
• Voltage regulator (L7805CV)

Shooter Body

Shooter Circuit

Main Component

• Photoresistor
• DC motors
• Stepping Motor (a8byj-48)
• Micro controller (89S51)
• Octal high voltage high current Darlington transistor arrays (ULN2803)
• Voltage regulator (L7805CV)

 ULN 2803

• A ULN2803 is an intergrated Circuit (IC) chip with a HIGH Voltage/High Current Darlington Transistor Array. It allows you to interface TTL signal with higher voltage/current loads
• The chip takes low level signals (operate at low voltages and low currents0 and acts as a relay of sorts itself, witching on or off a higher level signal on the opposite side.
•  

L7805CV

• The 78xx family is commonly used in electronic circuits requiring a regulated power supply due to their ease-of-use and low cost
• I.E. 7805=5V   7812=12V
• Disadvantage: Input voltage always needs to be higher than the regulated voltage

Miscellaneous Component

• Resistor (10k ohm *2)
• Capacitor (33 pF*2,1000nF*1)
• Oscillator(12MHz*1)
• Wires
• PVC tube (2" Diameter)

Schematic

 

Function 1: Switch

• Electronic switch on pin 9(reset) of microcontroller
• Using a photoresistor and a suitable resistor with voltage divider
• Photoresistor:

Bright = Small resistance

Dark=Large resistance

 

Voltage out connect to ping 9

Ping 9: High = turn off, Low = turn on

Theoretical Calculation

Photoresistor: 1K~14K ohm

R1,R2=10K ohm
Vin:5V

On:




Off:

Analysis

Light on

Light off

Function 2: DC Motor (Shooter)

• Two DC Motors- one spins counterclockwise, and the other spins clockwise
• Rubber on cap to increase the friction between surfaces

Function 3 : Stepping Motor (Gate)

• Brushless DC Motor
• Divide full rotation into a number of parts
• 28BYJ-48

• four phases five wires
• 12VDC
• 1100 ti 0110 to 0011 to 1001 to 1100
• Advantage: Precisely control the position of rotation

 

Serial Prorammer

• Homemade programmer
•  Connect to print pot

To control the steeping Motor

we use pre-programmed microcontroller

Criteria of Success:

All accomplished

Cost

•  

Component	Price/unit
ULN2803	0.32
AT89S51	0.75
L7805CV	0.2
Oscillator(12MHz)	0.04
Laser Diode	0.99
PVC TUBE	3.00
Stepper Motor	0.40
DC Motor	0.00
Miscellenuos  i.e. resistor, capacitor	0.05
Bread Board	1.67
Total	7.42

• Home made

Online/eBay

  

Joola Joola ipong Topspin Table tennis Ball Machine

$7700

Conclusion:

cheaper to build one than buy one