27-11-2012, 03:42 PM
EMBEDDED SYSTEM - HOME AUTOMATION SYSTEM
EMBEDDED SYSTEM--.pptx (Size: 2.13 MB / Downloads: 38)
HOME AUTOMATION SYSTEM
Initially ldr sensor is exposed to light and the ldr is in low impedance state, therefore sending a 1 signal to the pin P3.3,and all devices will be in OFF state.
When we obstruct the light falling on ldr sensor, the sensor will now be in high impedance state and therefore, a 0 signal is sent to the pin P3.3, this will send a high on input on pins P2.5, 2.6, 2.7 of lcd, then according to the program written in the microcontroller a note “welcome home” will be displayed on the screen of the lcd which indicates that the person have entered home
As a 0 signal is sent to the pin P3.3,this will send a high input to buzzer input pin P3.6.As high input is given to buzzer, the buzzer will beep when person has entered home. The buzzer will beep for 5msec only.
All the home appliances such as fan, light and relay will start working after 5msec and will continue until the ldr input is 0.
As soon as ldr input becomes 1, all appliances will stop working indicating person has moved out of the house.