The main objective of this project is to develop a low cost home automation system with a touch pad based control panel .
Step 1: Touch Pad Connections
Cheap touch pads are available at any mobile accessories shop.
A touch pad consist of 4 terminals. T1, T2, T3, T4 as show in image.
T1 & T3 are connected with +3.3V & gnd of arduino atmega8 board.
T2 & T4 are connected with analog pin A2 & A3 of controller.
Step 2: How Touch Pad Works
Touch pad gives analog value X & Y axis's value.
so we need to convert analog signal into digital signal. Arduino board have built in A to D converter.
We can segment the touch pad by observing the analog value with programming the controller.
Step 3: Arduino Atmega8
here we will use arduino atmega8.
Step 4: Programing
By simple if else condition we can segment the touch pad in 4 parts.
i have attached my program file.
Step 5: Relay Circuit
We are using relay circuit to control high power AC load with controller
I have attached circuit diagram of relay circuit.
Step 6: Connections
Now you can touch on any button and you will be able to turn on or off any appliances.