Happy Home Helper Jeremy Searle Apr 28, 2004 A Learning Home Automation System

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 sense human presence (Motion & E-Field Sensors)  Monitors power consumption and usage of devices plugged into Outlet control modules  Wireless communication between devices  Computer controlled window mechanisms  Computer controlled window blind mechanisms

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

Outlet Module Overview Serial Input/Output to/from Central μController Power from wall outlet Current Sensor Relay Device to be controlled by Outlet Module μController AC/DC converter Serial Input/Output to/from Peripherals (sensors, actuators) X2

Outlet Module State Machine OFF Manual _______ Auto ON Auto OFF _______ State 0 _______ ___ Relay Get Power Reading – NO 1 – YES 0 – OFF 1 – ON M – Manual Mode N – Auto Mode ON F – Auto Mode OFF M M F F N

Outlet Module Circuit

Current Sensor Reading highest sample = 0 lowest sample = 255 Wait 250 ms to let current spikes settle Loop for 64 ms { Take an A2D sample If current sample > highest sample highest sample = current sample If current sample < lowest sample lowest sample = current sample } power = (highest sample – lowest sample)*K Note: power accuracy is 0.125A or 15W if K = 2

Window Blind Actuation Modes -Manual -Ambient Light Tracking Close blinds Open blinds until Light = desired Every 10 minutes If reading is lower than desired Open blinds until Light = desired If reading is greater than desired Close blinds until Light = desired If reading can not reach desired Close blinds all the way Take pre-determined action -Maximum Light Tracking Every 10 minutes Open blinds all the way Close blinds while recording measurement If next reading is lower than Max Stop blind movement

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

How does it learn? The system learns by collecting usage statistics from the outlet modules. It then runs a pattern recognition algorithm to look for: -Devices that are used immediately following another device -Devices that are used at the same time of day habitually The system will then suggest that it takes control of these devices to help the user. NOTE: The system will never take control without the users consent

System Pros and Cons Pros -The ability to automate household devices with a PC interface at a nominal cost -The ability to monitor devices’ power consumption and usage -The ability to assist the user by recommending applications -The system learns, but the control remains completely in the hands of the user -The Outlet modules and the window blind actuation mount in seconds and require no tools to install -The system will record usage and power consumption statistics without the PC Cons -The system does require some thought preparation about which devices to control -The window actuation and the sensors require mounting -The system will not learn without the PC

Just a couple applications Set up a temperature sensor, window actuator, and a fan plugged into an Outlet module in a desired room. When the temperature gets too hot (user sets ‘too hot’ temp.) 1) Open the window 2) Turn on the fan Once the temperature gets cool again 1) Close the window 2) Turn off the fan Set up a window blind actuator, a motion sensor, and a lamp plugged into an Outlet module in a desired room. When the window blind actuator can’t get the desired light intensity 1) Close the window blinds all the way 2) Turn on the lamp 3) When the user is inactive for 30 min. turn off lamp When the time comes the next morning 1) Open the blinds to allow light

Thank You Any Questions ? me at