Andorid on /off project is very popular project in over all. Commercially it is very useful overall. With the help of micro controller. We control the output devices in the receiver circuit. For this purpose we use two micrcontroller in this project. Here we use ATMEL microcontroller in the transmitter and receiver circuit. In atmel series , here we use ic89s52 as a main processor.. and ic 89s52 in the receiver circuit as a main receiver circuit..
we will use HC-05 bluetooth module for communication between mobile and hardware. We will instal bluetooth data sending application on android mobile. Then we will select bluetooth device from list in add device. HC-05 will show as a device in list when we will give supply to bluetooth device. Bluetooth device on reciver side will get signal and will give serial out from module to controller. Controller will control the relay drive circuit. Relay will be 12v 100 ohm cube type to switch on/ off 220v device. We will use 3.5 inch touch screen to control devices. A voice processor will be used to speak voice tag. And a IR sensor pair will be used to on/off room light automatically
Pin no 12 to pin no 19 is port 1 ouput pins. On this pins we connect a push to on switches . One point of the switch is connected to the pins of the microcontroller and other pin is connected to the ground pin. Port p1.0 and port p1.1 is special pins of this microcontroller, so we connect a two pull up resistor to this pins.
Pin no 20 is connected to the positive supply. Pin no 10 is connected to the negative supply. Output infra red led is connected to the port p3.7. Infra red led is connected to the port p3.7 via pnp transistor. Here we use pnp transistor because output of the microcontroller is just negative so it is only capable to drive the pnp transistor. Pin no 1 is connected to the reset components via one capacitor and resistor 10 k in series. These two components auto reset the micrcontroller on power on . We transmit the data from the microcontroller in the serial communication. . Tx pin of the micrcontroller is pin 3 of this ic port p3.1. Here port p3.1 is also connected to the INT0 pin to give a timer 0 intruppt. Here we use total 10 ouput from the micrcontroller with frequency of 36 k hertz.