Automatic Pet Feeder

1
Automatic Pet Feeder

• Robert Fleming
• Vishak Ganesh
• Vu Tang
• Viet Nguyen
• Kevin Clark

2
What it is

• Modified automatic pet feeder
• Wireless beacon on a pet collar

http//www.terrificpets.com/pet_supplies/dog/bowls
-feeders/auto-feeders/14429.asp http//www.dobiede
tectives.com/dogtraproducts.html
3
What it does

• Automatically feeds pet upon approach
• Activated by collar device
• Dispenses food based on time
• Limits pet food intake

4
Why

• Automatic feeding
• Specialized diet
• Prevents feeding of strays
• Keeps food fresh

5
How it works

• Beacon device attached to pet collar broadcasts
  at 10 second intervals
• Matched receiver detects beacon at short ranges
• Microcontroller dispenses food based on user
  settings and time interval

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Collar Beacon
http//www.linxtechnologies.com/Documents/TXE-xxx-
KH2_Data_Guide.pdf
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Collar Beacon
TXE-418-KH2
Powered by coin cell battery
We want small duty cycle on transmitter 555 timer
circuit controls transmit enable pin on
TXE-418-KH2 chip
C1 10 uF, R1 100K R2 1M, Diode 1N4148, 9.1
duty cycle, 11 second period
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TXE

• TE goes high, TXE chip transmits
• Address specified by pins A0-A9
• Range controlled by LADJ

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RXD

• RXD-418-KH2 chip is matched receiver for TXE
  chip
• VT goes high when a signal from transmitter
  with matching address lines is detected
• D0-D7 replicate their analogs on the TXE chip

http//www.linxtechnologies.com/Documents/RXD-xxx-
KH2_Data_Guide.pdf
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Dog Feeder

• Matched receiver chip receives signals from
  collar beacon
• Microcontroller input is connected to valid
  transmission (VT) pin on RXD chip
• Microcontroller turns on drive motor in dog
  feeder
• Motor remains on for a length of time governed
  by user settings

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Microcontroller
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Microcontroller Code

• MinimumFeedAmount10 MaximumFeedAmount20
  StartOfLoop IsRXDChipVTPin high? -gtYes, Goto
  PrepareToFeedDog -gtNo, Wait 5, GoTo StartOfLoop
  PrepareToFeedDog FeedAmountPerDay(MaximumFeedA
  mount-MinimumFeedAmount)DIPSwitchValueMinimumFee
  dAmount TimeSinceLastFeedingNow-TimeLastFed
  MotorRunTimeTimeSinceLastFeeding/1Day
  FeedAmountPerDay Relay Control Pinhigh
• Wait MotorRunTime
• Relay Control Pinlow Wait 10 minutes GoTo
  StartOfLoop

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Feeder

• Motor is powered by normal AC power
• Power to motor is controlled by relay
• Relay is controlled by microcontroller

Relay controlled AC motor with auger to feed food
through at a constant rate
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Prototype Costs
Item Qty Cost Total
Dog Feeder 1 100 100
Microcontroller 1 15 15
Relay 1 2 2
Batteries 10 0.5 5
Transmitter 1 10 10
Receiver 1 16 16
Power Supply 1 10 10


Misc Parts  20 32
       
    Total 190
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Production Costs

Development Costs 62,149

Based on 1,500,000 units

Parts Cost 50
Assembly Labor 6
Testing Labor 3
Production Costs 144
Profit 21 12.40
Selling Price 165

Total Revenue 247,500,000
Total Profit 30,781,601
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Current Progress

• Working prototype collar beacon
• Working receiver circuit configuration
• Cypress Microcontroller (CY8C29466)
• Working feeder with reservoir and dispenser

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Collar Beacon
18
Receiver
19
Microcontroller
20
Feeder
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Problems

• Antenna directionality
• Lack of built in timer in microcontroller

22
Future Work

• Gain increased understanding of Cypress
  microcontroller
• Program microcontroller
• Design battery status indicator
• Fit battery to transmitter prototype
• Power receiver from Cypress EVAL board

23

• More than 140 million dogs and cats in the united
  states- every one of them eats!