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DTMF Based RobotDTMF Based RobotPrepared by :

R.ASHOK KUMAR (2501202810)

ARUN KUMAR (01313207311)

GUIDED BY:

SOFCON INDIA PVT. LTD.Faculty: Mr. RATNADITYA TIWARI

Mr. VINEET MATHURMr. DHRUV

What is Microcontroller?Microcontroller is a device which integrates a number of the components of a microprocessor system onto a single microchip. So a microcontroller combines onto the same microchip : -The CPU core -Memory (both ROM and RAM) -Some parallel digital I/O

INTRODUCTIONINTRODUCTION

MICROPROCESSOR

High end of market where performance matters

High power dissipation–high cost

Need peripheral devices to work

Mostly used in microcomputers

Targeted for low end of market where performance doesn’t matter

Low power dissipation – low cost

Memory plus I/O devices, all integrated into one chip

Mostly used in embedded systems

MICROCONTROLLER

CPU RAM ROMI/O

PORTTIMER SERIAL

PORT

CPURAM

ROM

I/O

TimerSerial

COM Port

DATA BUS

ADDRESS BUS

MICROPROCESSOR

MICROCONTROLLER

MICROCONTROLLERS vs. MICROPROCESSORS

Introduction to 8051-(MCS-51)

In 1981, Intel introduced an 8-bit microcontroller called 8051.128 bytes of RAM, 4K bytes of on-chip ROM, two timers, one serial port & four I/O ports (8-bit wide)External Interrupts

PIN DIAGRAM

One of the most useful features of the 8051 is that it contains four I/O ports (P0 - P3)

Port 0 Port 0 （（ pins 32-39pins 32-39 ）：）： P0P0 （（ P0.0P0.0 ～～ P0.7P0.7 ））8-bit R/W - General Purpose I/O8-bit R/W - General Purpose I/OOr acts as a multiplexed low byte address and data Or acts as a multiplexed low byte address and data bus for external memory designbus for external memory design

Port 1 Port 1 （（ pins 1-8pins 1-8 ）） ：： P1P1 （（ P1.0P1.0 ～～ P1.7P1.7 ））Only 8-bit R/W - General Purpose I/OOnly 8-bit R/W - General Purpose I/O

Port 2 Port 2 （（ pins 21-28pins 21-28 ）：）： P2P2 （（ P2.0P2.0 ～～ P2.7P2.7 ））8-bit R/W - General Purpose I/O8-bit R/W - General Purpose I/OOr high byte of the address bus for external memory Or high byte of the address bus for external memory designdesign

Port 3 Port 3 （（ pins 10-17pins 10-17 ）：）： P3P3 （（ P3.0P3.0 ～～ P3.7P3.7 ）） General Purpose I/OGeneral Purpose I/O if not using any of the internal peripherals (timers) or if not using any of the internal peripherals (timers) or external interrupts.external interrupts.

Each port can be used as input or output (bi-direction)

8051: Pin Description

Port 3 Alternate Functions

8051: Timer Mode Register

Timer mode register is used to set the various timer operation modes

Both timer 0 & timer 1 use the same register, called TMOD

It is an 8-bit register The lower 4-bit are used for timer 0 & upper 4-bit are

used for timer 1 The lower 2-bits are used to set the timer mode &

upper 2-bits to specify the operation

8051: Timer Mode Register | Contd..

GATE C/T M1 M0 GATE C/T M1 M0

Timer 1 Timer 2

GATE : If 1 -> timer/counter is enabled only when interrupt is enabled

0 -> the timer is enabled whenever the TRx control bit is set

C/T : If 1 -> counter operation (input from Tx input pin) 0 -> timer operation (input from internal system

clock)

M1 M0 MODE Operating Mode

0 0 013-bit timer mode

(8-bit timer/counter THx with TLx as 5-bit Prescaler)

0 1 116-bit timer mode

(16-bit timer/counter THx and TLx are cascaded)

1 0 2

8-bit auto reload(8-bit auto reload timer/counter; THx holds a value which is to be reloaded TLx each time it

overflows)

1 1 3 Split timer mode (256 +256 times)

Peripheral InterfacingPeripheral Interfacing

LED LCD

BUZZERMOTOR

RS 232 IRSENSOR

7 SEGMENT DISPLAY

DTMF BASED ROBOTDTMF BASED ROBOT

TECHNOLOGY USEDTECHNOLOGY USED

Dual-Tone Multi-Frequency (DTMF) Dual-tone multi-frequency (DTMF) signaling is used for telecommunication signaling over analog telephone lines in the voice-frequency band between telephone handsets and other communications devices and the switching center. The version of DTMF used for telephone tone dialing is known by the trademarked term Touch-Tone (canceled March 13, 1984), and is standardized by ITU-T Recommendation Q.23. It is also known in the UK as MF4. Other multi-frequency systems are used for signaling internal to the telephone network.

A DTMF TELEPHONE KEYPAD

The contemporary keypad is laid out in a 3×4 grid, although the original DTMF keypad had an additional column for four now-defunct menu selector keys. When used to dial a telephone number, pressing a single key will produce a pitch consisting of two simultaneous pure tone sinusoidal frequencies. The row in which the key appears determines the low frequency, and the column determines the high frequency. For example, pressing the '1' key will result in a sound composed of both a 697 and a 1209 hertz (Hz) tone. The original keypads had levers inside, so each button activated two contacts. The multiple tones are the reason for calling the system multi-frequency. These tones are then decoded by the switching center to determine which key was pressed.

DTMF KEYPAD FREQUENCIESDTMF KEYPAD FREQUENCIES

1209 Hz 1336 Hz 1477 Hz 1633 Hz 697 Hz 1 2 3 A 770 Hz 4 5 6 B 852 Hz 7 8 9 C 941 Hz * 0 # D

Tones #, *, A, B, C, and DThe engineers had envisioned phones being used to access computers, and surveyed a number of companies to see what they would need for this role. This led to the addition of the number sign (#, sometimes called 'octothorpe' in this context) and asterisk or "star" (*) keys as well as a group of keys for menu selection: A, B, C and D. In the end, the lettered keys were dropped from most phones, and it was many years before these keys became widely used for vertical service codes such as *67 in the United States and Canada to suppress caller ID.

CIRCUIT DIAGRAM

IC 8870

BLOCK DIAGRAMBLOCK DIAGRAM

SOFTWARES USEDSOFTWARES USED

1. KIEL MICROVISION (EMULATOR) µVision Keil provides IDE for 8051 programming & is very easy to use. When starting a new project, simply select the microcontroller you use from the Device Database and the µVision IDE sets all Compiler, Assembler, Linker, and Memory options. It’s device database is large which supports many ICs of the 8051 family. A HEX file can be created with the help of Keil which is required for burning onto chip. It has a powerful debugging tool which detects most of the errors in the program.

3. PROTEUS

Proteus is software for microprocessor simulation, schematic capture, and printed circuit board (PCB) design. It is developed by Labcenter Electronics.The XGameStation Micro Edition was designed using Labcenter's Proteus schematic entry and PCB layout tools.

2. 8051 LOADER

8051 loader is a software developed by robosapiens. The HEX file created with the help of keil was selected through it for programming the microcontroller.

In order to control the robot, you need to make a call to the cell phone attached to the robot (through head phone) from any phone, which sends DTMF tunes on pressing the numeric buttons. The cell phone in the robot is kept in ‘auto answer’ mode.

WORKING

Now you may press any button on your mobile to perform actions as listed in Table III. The DTMF tones thus produced are received by the cellphone in the robot. These tones are fed to the circuit by the headset of the cellphone. The CM8870 decodes the received tone and sends the equivalent binary number to the microcontroller. According to the program in the microcontroller, the robot starts moving.

When you press key ‘2’ (binary equivalent 00000010) on your mobile phone, the microcontroller outputs ‘10001001’ binary equivalent. Port pins PD0, PD3 and PD7 are high. The high output at PD7 of the microcontroller drives the motor driver (L293D). Port pins PD0 and PD3 drive motors M1 and M2 in forward direction (as per Table III). Similarly, motors M1 and M2 move for left turn, right turn, backward motion and stop condition as per Table III.

PROGRAMPROGRAM#include<REGX51.H>#define DTMF P1#define MOTOR P2void main(){DTMF=0x00;MOTOR=0x00;while(1){if(DTMF==0x02) // FORWARD {MOTOR=0x09;}if(DTMF==0x08) // BACKWARD{MOTOR=0x06;}

if(DTMF==0x04) // LEFT TURN{MOTOR=0x08;}if(DTMF==0x06) // RIGHT TURN{MOTOR=0x01;}if(DTMF==0x05) // BRAKE{MOTOR=0x00;}}}

FLOW CHARTFLOW CHART

ADVANTAGES

1. Effective control of home appliances. 2. Home automation using mobile phone. 3. Increases power efficiency. 4. Increases appliances lifetime. 5. Power wastage is reduced.

DISADVANTAGES

1. Cell Phone Bill.2. Charging problems as mobile batteries go down.3. Cost of project is high if cell phone is included.

APPLICATIONSAPPLICATIONS

1) SCIENTIFIC Remote control vehicles have various scientific uses including working in hazardous environments, deep ocean, and space exploration.

2)MILITARY AND LAW ENFORCEMENT Military usage of remotely controlled military vehicles dates back to the first half of 20th century. Soviet Red Army used remotely controlled Tele-tanks during 1930s in the Winter War and early stage of World War II.

3) SEARCH AND RESCUE  UAVs will likely play an increased role in search and rescue in the United States.

 4)RECREATION AND HOBBY  Like Radio-controlled model, Small scale remote control vehicles have long been popular among hobbyists. These remote controlled vehicles span a wide range in terms of price and sophistication.

FUTURE SCOPE AND IMPROVEMENTSFUTURE SCOPE AND IMPROVEMENTS

1. IR SENSORS  IR sensors can be used to automatically detect & avoid obstacles if the robot goes beyond line of sight.

2. PASSWORD PROTECTION  Project can be modified in order to password protect the robot so that it can be operated only if correct password is entered.

3. ALARM PHONE DIALER  By replacing DTMF Decoder IC CM8870 by a 'DTMF Transceiver IC’ CM8880, DTMF tones can be generated from the robot. So, a project called 'Alarm Phone Dialer' can be built which will generate necessary alarms.

4. Adding a CAMERA  If the current project is interfaced with a camera (e.g. a Webcam) robot can be driven beyond line-of-sight

THANK THANK YOU YOU