REQUIREMENT:1. AtMega 16 microcontroller2. L293D motor driver IC3. Bluetooth module (HC05)4. Chassis5. Motors & Wheels6. Mobile phone (Android + Bluetooth compatibility)7. Battery (for car section)DESCRIPTION:Have you ever wondered of operating a toy car with you own mobile phone? Yes I have made such a thing. This project involves the communication between your mobile phone and the car. Here I have used the internal accelerometers of the mobile phone to operate my toy car.The system communicates wirelessly over Bluetooth interface, thus we require a phone with Bluetooth compatibility. Moreover I have made an Android Application for the same task therefore the phone must have ANDROID operating system JNow this project deals with two sections: CAR section Mobile phone (ANDROID APP)Lets first talk about the Car section, It comprises of AtMega 16 microcontroller, L293D motor driver IC and most importantly the Bluetooth module which makes this whole task work wirelessly. I have used an 11.1 V LI-PO battery (Lithium Polymer) to assure long working duration.The same 11.1 volts is given to the motors for working properly while a 7805 voltage regulator regulates this voltage to 5V so that the remaining circuit functions properly without any risk of being damaged.The next important part of this section is the Bluetooth module: HC05. These modules follow the Bluetooth protocol to get the job done wirelessly. Bluetooth are nothing but ultra high frequency radio waves. They cover a larger area and work quite well as compared to those RF 343 Hz modules.Moreover these Bluetooth modules provide a chance to interact with other Bluetooth compatible devices like mobile phone etc.The communication is being done with UART interface at 9600 baud rate.The assembling of the car section is shown below:

Now talking about the mobile part, now a days every mobile has an accelerometer sensor; I have used this sensor to give me the orientation vales for further processing. I have made an ANDROID APP which extracts this data and send it over to the Bluetooth module present in the CAR section. This data is then processed in my AtMega 16 IC to tell L293D IC what to do to the motors connected to it. Like if I get W, this tells the microcontroller to move the car forward similarly S, A, D and make the car move in backward, left, right and stop positions.The most interesting thing about this section is that we first need to calibrate the phones accelerometer data into our microcontroller IC so that perfect results are obtained each time this car is turned on.I have made this ANDROID APP using freeware software known as APP INVENTOR 2. This has been developed by the students of MIT for those who find it difficult to learn android programming. They make use of simple block arrangements to perform any android based task. I find it very useful for myself and for those who dont know how to make android apps!!! Thanks a lot to MIT.Heres a look of my ANDROID APP. It gives me the data for 3 axis: X, Y and Z.This data is then analysed in my microcontroller which it gets via Bluetooth. This project is interesting because it involves electronics as well as android stuff.In the coding part I have made use of the header file : to deal with UART functions. UART=Universal Asynchronous Receiver Transmitter. In this header filegetchar_uart()function feeds microcontroller with the Bluetooth received data..