Michael BroskiJonathan MulvaineJosh SchortgenPhillip Byers

TEAM BOAR

The objective of this project is to roast a complete hog (approximately 150 lbs) at a constant user-specified temperature until the internal temperature of the two thickest parts of the meat reaches the desired user-specified temperature. When the hog reaches the second specified temperature, a user-configured timer will start down, which upon completion will notify the user via remote that the meat is considered cooked and ready for consumption. The roaster must use propane as an energy source, regulate the ambient temperature in the tank, withstand hazardous outdoor conditions, and wirelessly transmit readouts to a remote display device that is sized to be comfortably placed in the users pocket or on the user’s keychain.

ABSTRACT

The block diagram below is the most up to date plan of action for interfacing with the base station.

ABSTRACT CONTINUED

An ability to measure the internal temperature of two separate points in the meat and the temperature inside the roaster using RTD sensors.

An ability to control the temperature inside the roaster by modifying gas flow using a PWM signal to operate a voltage controlled gas valve.

An ability to store and load cooking profiles from memory.An ability to automatically ignite and detect whether a flame

is present.An ability to wirelessly communicate temperature information

to a remote display device.

PSSC’S

The Microcontroller used (MC9S12H256VPVE) will be the main control of the base station for the hog roaster.

Xbee Wireless – SCI LCD – SPI & PTT Digital Input – ~5 I/O Pins Sensor Data – ATD Propane Flow Valve - PWM

Tx and Rx of SCI to control Xbee 1 SPI Port to drive the LCD Data Port T will drive the LCD command pins Port A will read the state of the pushbuttons

and RPG Port AD will control the sensor input data

from the temperature sensors Port B will be used to control the flow rate

valve and the automatic ignition

HARDWARE DESIGN

Mock Up

BASE STATION

MC9S12H256VPVE

Xbee Wireless Module

Microcontroller

Tx Rx

TxRx

~120VAC

Power Supply

5V

160x128 LCD

PTT

SPI Shift Register

PTA{…}

BDM

VALVE

3.3V

PTB

RTD

PTADAmplification

Circuit

LPF with Gain Controller

Ignite

The circuits here are used to provide a secondary translation to provide the microprocessor with more meaningful data it can use.

SECONDARY CIRCUITS

This circuit is used to control the voltage-to-pressure valve used to regulate the gas flow from the propane tank.

This circuit is a low pass filter with gain. It takes an input of ~100kHz PWM signal with a duty cycle between 50-100%. An increase of the duty cycle results in a decrease of the DC output due to the inverting op-amp

This circuit will be used to amplify the output of the temperature sensors.

Due to the fact that the temperature sensors only output around 100-300mV, the onboard ATD converter would not be able to accurately use the data. Therefore the output will first be amplified to provide a swing of at least 1-3V, allowing for greater accuracy.

Mock Up

WIRELESS REMOTE

Vibrator

Xbee Wireless Module

Tx Rx

TxRx

MC9S12C32

Buzzer

16x2 LCD

Shift RegisterPTT

SPI

PWM

{..}

Pushbuttons

PTAD