ReTemp Design Review 09/09/04 By Kenny Chung Amish Rughoonundon Amish Rughoonundon

Overview Objective Objective Performance Specification Performance Specification Hardware Hardware Software Software Milestone Milestone Tentative Timeline Tentative Timeline

Objectives Design of a system that allows setting the temperature of a house from a remote location using the internet.

Performance Specifications Abilities for the user: Abilities for the user: –Increase/decrease the temperature by 1 o unit –Locally/remotely set and monitor the temperature Abilities for the system: Abilities for the system: –Maintain steady temperature within 2 o unit –Attain temperature as low as the outside temperature –Attain a maximum temperature of 27 o C/80 o F User Restriction User Restriction –Temperature cannot be set lower than the outside temperature –Temperature cannot be set higher than 27 o C/80 o F

High Level Description System Interface Server

Sensor NTC – resistance decreases as temperature increases NTC – resistance decreases as temperature increases R 2 value indicates high correlation R 2 value indicates high correlation Linearity confirms Steinhart-Hart Equation Linearity confirms Steinhart-Hart Equation

Heating Device

Cooling Device

Software Php server side scripting Php server side scripting Java Java Microsoft IIS web server Microsoft IIS web server mySQL database mySQL database HC12 assembly language HC12 assembly language

Server Flowchart

Java Interface Flowchart

HC12 Uses Serial interrupt Uses Serial interrupt –Interrupt occurs when a query is obtained from the java program. –Query type: FF: Request temperature reading from sensors. FF: Request temperature reading from sensors. Any other value: Stored as wanted temperature. Any other value: Stored as wanted temperature. Uses Timer interrupt Uses Timer interrupt –Interrupt occurs every 33 ms. –Temperature are read in and stored in memory. Controller: Controller: –Bang bang controller.

User Interface Demo

Current Milestone DescriptionStatus Increase/decrease the temperature by 1 o unit Done Locally/remotely set and monitor the temperature Done Maintain steady temperature within 2 o unit In Progress Attain temperature as low as the outside temperature In Progress Attain a maximum temperature of 27 o C/80 o F In Progress Temperature cannot be set lower than the outside temperature Done Temperature cannot be set higher than 27 o C/80 o F Done

Tentative Timeline MonthWeekObjectiveStatus SEPTEMBER 1Design review IN PROGRESS 2Complete the database access using the java program and set up the controller in HC12. IN PROGRESS 3Finish calibrating the hardware and connect the board to the sensors IN PROGRESS 4Preliminary testing and adjustments IN PROGRESS OCTOBER 1Final testing. IN PROGRESS 2Report write up and Project poster design IN PROGRESS 3Demo IN PROGRESS 4Demo IN PROGRESS

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