DTMF Controlled Robot

Transcription

1 DTMF Controlled Robot Devesh Waingankar 1, Aaditya Agarwal 2, Yash Murudkar 3, Himanshu Jain 4, Sonali Pakhmode 5 ¹Information Technology-University of Mumbai, India Abstract- Wireless-controlled robots use RF circuits, which have the drawbacks of limited working range, limited frequency range and limited control. The objective of designing our robot is to facilitate the humans for surveillance purpose. Use of a mobile phone for robotic control can overcome these limitations. Our robot s movement is controlled by a mobile phone over a large distance, even from different cities. It provides the advantages of robust control, very large working range as that of the coverage area of the service provider, no interference with other controllers and up to nine controls. Although the appearance and capabilities of robots vary vastly, all robots share the features of a mechanical structure under some form of control. The control of robot involves three distinct phase namely perception, processing and action. The preceptors are camera mounted on the robot, processing is done by the on-board microcontroller, and the task is handled using motors or with some other actuators. Keyword- mobile phone; dual tone multiple frequency; network; micro controller; motor driver; I. INTRODUCTION Radio Controlled Vehicle (RCV) is used frequently to refer to the control of model vehicles from a hand-held radio transmitter. Industrial, military, and scientific research organizations make use of radio-controlled vehicles as well. A remote control vehicle is defined as any mobile device that is controlled by a means that does not restrict its motion with an origin external to the device. It is often seen in a radio control device; there is a cable between controller and vehicle, or an infrared controller. A remote control vehicle differs from a robot. An RCV is always controlled by a human and takes no positive action autonomously. The key technologies which underpin this field are that of remote vehicle control. It is vital that a vehicle must be capable of proceeding accurately to a target area; manoeuvring within that area to fulfil its mission and returning accurately and safely to base. This project includes a robotic car consisting of a cell phone, DTMF decoder and microcontroller. The transmitter is a handheld mobile phone. The technology used is explained below. II. OVERVIEW OF THE TECHNOLOGY DTMF stands for dual tone multiple frequency. It is the signal to the phone company that generates when you press an ordinary telephone's touch keys. In the United States and perhaps elsewhere, it's known as "Touchtone phone. DTMF has generally replaced loop disconnect dialling. DTMF generation is made of audio signal of two tones between the frequency of 697Hz and 1633Hz. The DTMF technique outputs distinct representation of 16 common alphanumeric characters (0-9, A-D, *, #) on the telephone. With DTMF, each key you press on your phone generates two tones of specific frequencies. So that a voice can't imitate the tones, one tone is generated from a high-frequency group of tones and the other from a low frequency group. Devesh, Aaditya,Yash,Himanshu,Sonali Page 24

2 Here are the signals you send when you press your touchtone phone keys: TABLE 1 FREQUENCY TABLE Digit Low Frequency High Frequency * # When any DTMF code has been received at mobile phone it can be audible through speaker. So to decode this DTMF code speaker output itself can be used. Output of speaker is connected to IC MT8870 which is DTMF decoder IC. It is used widely to decode DTMF code. It gives 4-bit digital output Q1, Q2, Q3 and Q4 according to the received key (see Fig.2). Following figure shows the equivalent digital output for each key. TABLE 2 BINARY CODE FOR EACH KEY Key Q4 Q3 Q2 Q * # A B C D Devesh, Aaditya,Yash,Himanshu,Sonali Page 25

3 III. FRAMEWORK OF THE SYSTEM The above mentioned system is a robot that will be used for surveillance purposes. This robot is different from its existing counterparts in various aspects. Although every robot shares common features, our DTMF controlled robot does not have limitation of coverage area and frequency interference. This system provides us with up to twelve controls. The major building blocks of this project are:- 1. Regulated Power Supply 2. GSM Phone 3. Microcontroller based Control Unit 4. Robot Mechanical Assembly 5. DTMF Drivers Fig.1 Block Diagram According to designed block diagram we can see that the heart of above system is its processing unit that is controller 89s51. It receives signal from the user which are converted into machine language by the DTMF decoder before passing it to microcontroller which provides the command to the motor driver. The motors perform the intended command. IV. USE CASE FOR THE SYSTEM Devesh, Aaditya,Yash,Himanshu,Sonali Page 26

4 Fig. 2 Use Case As we can see in the figure 2 the user initiates the connection by making a call to the robot which has a mobile attached to it. After the connection is established the user sends the command to the robot. The DTMF decoder in the circuit receives this command and coverts the signal for the microcontroller, once microcontroller reads this signal they send instruction to the motor driver for the action to be performed by the robot. V. SOFTWARE USED In our project i.e. DTMF Controlled robot, we used a Microsoft paint and online website and for designing a flowchart, use case diagram and block diagram. For burning a program in a microcontroller we use software like Keil, Embedded C language, Flash magic. Keil:- Keil is mainly used to burn a program of any programming language into suitable machine language that is.hex file which is used to compile a program and find a bug in a program. It is an open source and easily available. Keil development tools support every level for software developer from the professional application engineer to the student just learning about software development. Flash magic:- It is used to burn a program in an 8051 microcontroller; it is specific software for While getting a file from keil i.e., hex file and it is directly burn in microcontroller It is easy to used, and simple to handle software. Flash Magic is a tool which used to program hex code in EEPROM of micro-controller. it is a freeware tool. It only supports the microcontroller of Philips. We can burn a hex code into that controller which supports ISP (in system programming) feature. To check whether our micro-controller supports ISP or not take look at its datasheet. So if your device supports ISP then you can easily burn a hex code into EEPROM our device. We can also use an Embedded C language for burning an 8051 IC with a suitable program. Devesh, Aaditya,Yash,Himanshu,Sonali Page 27

5 VI. VEHICLE MOVEMENT Chassis is the platform of the robot vehicle, which is used to mount the mobile and DTMF circuitry. A cell phone is connected to a vehicle through 3.5mm audio jack. For the movement of the robot, a call is made from the calling subscriber to the cell phone connected to robot, the cell phone automatically receives the call and the vehicle is ready for movement. According to the generated DTMF frequencies from the cell phone, the caller can control the robotic movement. Fig.3 Demonstrating our Robot Micro controller In our project the micro controller is programmed in such a way that it receives DTMF input from the receiving end and it drives the motors accordingly micro controller is used as it is cheap and easily available. Some of the features of 8051 are: 4 KB on chip program memory. 128 bytes on chip data memory(ram) [32 bank reg + 16 bit addressable reg + 80 general purpose reg ] 4 reg banks. 128 user defined software flags. 8-bit data bus 16-bit address bus 16 bit timers (usually 2, but may have more, or less). 3 internal and 2 external interrupts. Bit as well as byte addressable RAM area of 16 bytes. Four 8-bit ports, (short models have two 8-bit ports). 16-bit program counter and data pointer. 1 Microsecond instruction cycle with 12 MHz Crystal Devesh, Aaditya,Yash,Himanshu,Sonali Page 28

6 L293D IC L293D is designed for controlling two way geared DC motors which further takes commands from the DTMF decoder through microcontroller. Fig.4 Pin Configuration of L293D Battery The battery used for our robot vehicle is of 12V DC. It is connected to circuit. It is mounted over chassis. VII. CONCLUSION By developing a cell phone operated robotic car, we have overcome the drawbacks of the conventionally used RF circuits. This RCV includes advantages such as robust control, minimal interference and a large working range. The car requires four commands for motion control. The remaining twelve controls are available to serve purposes dependant on the area of application of the RCV. REFERENCES [1] [2] [3] [4] Cell phone operated landroevle electronics For You Magazine, Edition (July 2008) Edition. [5] DTMF Tester Electronics For You Magazine [6] [7] Devesh, Aaditya,Yash,Himanshu,Sonali Page 29

7 [8] - DECODER.html [9] [10] [11] [12] Devesh, Aaditya,Yash,Himanshu,Sonali Page 30