This document describes a touch screen controlled automatic wheelchair and home appliance control system. The system uses a touch screen interface to control the movement of an electric wheelchair in all directions. It also allows the user to control home appliances remotely through the same touch screen interface and a Zigbee wireless communication system. The goal is to give physically disabled people independent mobility and control over their environment through a simple touch-based interface.

1. TOUCH SCREEN CONTROLLED
AUTOMATIC WHEEL CHAIR AND
HOME APPLIANCES.
Presented by Under the guidance of
P.V.BHAVANA Mr. M.SUNDARARAO sir
12C51A0458 Asst.prof

2. CONTENTS
 Abstract
 Motivation
 Challenges
 Methodology
 Application
 Pros and Cons
 Future scope
 Conclusion

3. 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.

4. 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.

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

6. 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

7. Transmitter block diagram

LPC2148
Micro
controller
Power
supply 16x2 LCD
Zigbee
transmitter
Driver
circuit for DC
motor
Dc
motor
Dc
motor
wheel
wheel
Resistive
Touch
screen
switch

8. 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

9. 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.

10. 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

11. 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.

12. 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 microcontroller
AT89S52 ,that controls the home appliances.

13. AT89S52
MICRO
CONTROLLER
Power supply
Zigbee
reciever
16x2 LCD
Darlington pair for two
relays
relay1
relay2
bulb

14. 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.

15. 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.

16. 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

17. APPLICATIONS
For paralyzed people
In hospitals
For para athletics

18. 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.

19. 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.

20. 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.