TOUCH SCREEN CONTROLLED AUTOMATIC WHEEL CHAIR AND HOME APPLIANCES.

Presented by Under the guidance of P.V.BHAVANA Mr. M.SUNDARARAO sir12C51A0458 Asst.prof

CONTENTS

Abstract Motivation Challenges Methodology Application Pros and Cons Future scope Conclusion

ABSTRACT

It is very difficult for the physically challenged people, to move and operate house hold appliances by their own.

The proposed seminar based on touch screen technology enables them to move independently without any external aid and at the same time it also helps them to operate home appliances using wireless communication.

MOTIVATION

A physically disabled person come across many problems while locomotion and it becomes more difficult for such a person to go near and operate the conventional switches .

To solve this problem a wheel chair is designed which can be controlled by the user and at the same time conventional switches are replaced with centralized control system to operate the house hold appliances located at remote places.

CHALLENGES Large touch screen leads to decrease in battery life. Stress on human fingers for large use. Automatic braking system is not in use.

METHODOLOGY

Touch screen technology is the direct manipulation type, gesture based technology.

A switch is placed on the wheel chair to perform two different types of operations i.e. either the movement of wheel chair or the house hold appliances control

Transmitter block diagram

LPC2148Micro controller

Power supply 16x2 LCD

Zigbeetransmitter

Drivercircuit for DC motor

Dcmotor

Dc moto

r

wheel

wheel

ResistiveTouch screen

switch

POWER SUPPLY

A power supply circuit is used to feed the microcontroller with 3.3v

SWITCH A switch is used to perform two different operations For one state of switch the signal from the touch screen is given

to the wheelchair to move in required direction. For second state ,the input signal is used to control house hold

appliances using zigbee technology

Touch screen A touch screen is capable of detecting and effectively

locating a touch over its display area. It is a 4-wire analog resistive touch screen, that is by

touching the screen at one point, resistance will vary for both X and Y axis.

By applying voltage across each axis, a change in resistance results in a change in voltage which is analog.

Lpc2148 microcontroller The analog output produced by the touch screen is given to

the ADC pins of micro controller. LPC2148 process and compares the obtained digital values

with the predefined range values. Accordingly it send instructions to direct the movement of

the chair and when switch is in state two, the same input is considered to control home appliances

Dc motors and its drivers Two 100rpm DC motors are used to control the movement of

wheel chair. To drive the motors having high torque, a driver circuit is

designed using mosfets and L293D An L293D circuit can control two motors simultaneously which in turn controls four wheels.

Zigbee transmitter and receiver

ZigBee is an IEEE 802.15.4-based specification for a suite of high-level communication protocols used to create personal area networks with small, low-power digital radios.

When switch state is zero, the input from the touch screen is given to ARM7 microcontroller, which transmits the input data serially to zigbee transmitter.

The data transmitted by zigbee transmitter is received by zigbee receiver in the receiving circuit.

The zigbee receiver sends the information to the microcontrollerAT89S52 ,that controls the home appliances.

Receiver block diagram

AT89S52 MICRO

CONTROLLER

Power supply

Zigbee reciever

16x2 LCD

Darlington pair for two relays

relay1

relay2

bulb

At89s52 microcontroller.

The AT89S52 is a low-power, high-performance 8-bit microcontroller with 8K bytes of in-system programmable Flash memory

It receives the digital signal from zigbee receiver It processes the received information to Darlington pair of relays.

Darlington pair

Two transistors with a common collector configuration and connected in a cascaded form constitute a Darlington Pair.

A Darlington pair circuit is designed to get current gain to operate the relay.

Relay A relay is an electromagnetic switch operated by a relatively

small electric current that can turn on or off a much larger electric current.

Hence in the receiver section relays act as switches that are connected with different home appliances.

16X2 LCD The LCD acts as an output device to display the function which is being performed by the microcontroller

APPLICATIONS

For paralyzed people

In hospitals

For para athletics

PROS AND CONS

PROS Highly user friendly. Easy to design and manufacture. Highly portable Less wired complexion.

CONS Collision avoidance mechanism

is absent. Absence of auto braking

mechanism.

FUTURE SCOPE

We can use voice command IC to interface our voice signal with micro controller.

This project can be extended by including GSM that sends an SMS during emergency.

Research is going on development of handicap wheelchair using nervous system of human.

CONCLUSION

Touch screen based control system is implemented for moving the wheel chair in all directions and the same control system is used to switch on and off the home appliances located in remote places using Zigbee technology.

This system will be very helpful for the people who cannot move without any external aid.