Automatic Pet Feeder

Robert FlemingVishak Ganesh

Vu TangViet NguyenKevin Clark

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.asphttp://www.dobiedetectives.com/dogtraproducts.html

What it does

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

Why

Automatic feeding Specialized diet Prevents feeding of strays Keeps food fresh

How it worksBeacon device attached to pet collar broadcasts at 10 second intervalsMatched receiver detects beacon at short rangesMicrocontroller dispenses food based on user settings and time interval

Collar Beacon

http://www.linxtechnologies.com/Documents/TXE-xxx-KH2_Data_Guide.pdf

Collar Beacon

We want small duty cycle on transmitter

555 timer circuit controls transmit enable pin on TXE-418-KH2 chip

TXE-418-KH2

Powered by coin cell battery

C1: 10 uF, R1: 100K R2: 1M, Diode: 1N4148, 9.1% duty cycle, 11 second period

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

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

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

Microcontroller

Microcontroller Code

MinimumFeedAmount=10 MaximumFeedAmount=20 StartOfLoop: IsRXDChipVTPin high? ->Yes, Goto PrepareToFeedDog ->No, Wait 5, GoTo StartOfLoop PrepareToFeedDog: FeedAmountPerDay=(MaximumFeedAmount-MinimumFeedAmount)*DIPSwitchValue+MinimumFeedAmount TimeSinceLastFeeding=Now-TimeLastFed MotorRunTime=TimeSinceLastFeeding/1Day * FeedAmountPerDay Relay Control Pin=highWait MotorRunTimeRelay Control Pin=low Wait 10 minutes GoTo StartOfLoop

Feeder

Relay controlled AC motor with auger to feed food through at a constant rate

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

Prototype CostsItem 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

Production Costs

Development Costs $62,149

Based on: 1,500,000units

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

Total Revenue $247,500,000 Total Profit $30,781,601

Current Progress

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

dispenser

Collar Beacon

Receiver

Microcontroller

Feeder

Problems

Antenna directionality Lack of built in timer in microcontroller

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

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