Happy Home Helper Electrical Design Presentation Jeremy Searle Mar 17, 2004

Background  Home Automation is used for various household controls (lights, security, entertainment)  Systems tend to be expensive  Systems completely rely on the home PC which can be unreliable (Hackers, Crash, Power Surge, Virus)  Systems must be programmed to accomplish tasks and do not learn

Problem Statement To design a home automation system that is capable of learning and executing daily routines at an economical cost.

Solution  Central micro-controller unit  Outlet control modules  PC user interface  Sensors to control lights/sense walking path  Remember routines by averaging sensor data and user input data  Wireless communication between devices  Computer controlled window and door mechanisms

System Overview Central uController Outlet Module Data Flow Human Input Misc. Sensors

Outlet Module Overview Serial Input/Output to/from Central uController Power from wall outlet Current Sensor Relay Device to be controlled by Outlet Module uController AC/DC converter Serial Input/Output to/from Peripherals (sensors, actuators)

Outlet Module Circuit

AC/DC Converter

Relay Circuit

Current Sensor Allegro ACS750xCA-050 Senses Current up to 50 Amps Very low resistance for low power loss (R = 130 uOhms)

Central Micro-Controller Overview Serial Input/Output to/from Outlet Modules Serial Input/Output to/from PC NVRAM uController RTC

Schedule

Thank You Any Questions ?