30-09-2016, 03:46 PM
1457092936-safety.pptx (Size: 1.01 MB / Downloads: 6)
Introduction:
For the blind it is difficult to step out without someone’s help. To make their life simpler, our Electronic Safety Assistance For Blind Using 89C52 will alert them of any obstacle in the path. The Safety Assistance For Blind comprises of IR sensor. The transmitter sends the rays which fall on the object and upon reflection is sensed by receiver. The event is being processed through microcontroller which intimates the Blind Person of obstacle.
Components Required:
IR Sensor TSOP 1738
Microcontroller 89C52
In4007-Diode-2
Power Supply
Capacitors
Resistors
40 pin base-1
AT89C52 -1
11.0592MHZ-Crystal -1
Buzzer
CIRCUIT DESIGNING AND WORKING
AT89C52 is the heart of the design.The IR waves are transmitted into free space and when touches the obstacle it gets reflected .The reflected waves are receives by the IR receiver. The demodulator is used to process the signal and it gives the processed signal to the microcontroller .The microcontroller then drives the buzzer by which the blind person can come to know about the obstacle. The microcontroller is provided with an oscillator frequency 12mhz.
POWER SUPPLY:
Description:
The Power Supply is a Primary requirement for the project work. The required DC power supply for the base unit as well as for the recharging unit is derived from the mains line. For this purpose center tapped secondary of 12V-012V transformer is used. From this transformer we getting 5V power supply. In this +5V output is a regulated output and it is designed using 7805 positive voltage regulator. This is a 3 Pin voltage regulator, can deliver current up to 800 milliamps.
IR Sensor:
An IR transceiver is capable of both sending and receiving infrared data. The basic concept of IR is obstacle detection is to transmit the IR signal in a direction and a signal is received at the IR receiver when the IR radiation bounces back from a surface of the object .
Here in the figure the object can be anything which has certain shape and size , the IR LED transmits the IR signal on to the object and the signal is reflected back from the surface of the object . The IR receiver can be a photodiode which decodes the signal.
Photo Diode:
A photo diode is a semiconductor device that converts light into current . It absorbs the signal and with respect to this,,the microcontroller process.
Buzzer:
It is the output device .Whenever obstacle is detected after the buzzer is enabled.
DUMP ING A PROGRAM:
Burning a program in microcontroller is an essential part of building microcontroller projects.
It is the process of transferring a program code to the microcontroller’s memory from a compiler software.Program is converted into hex file using kiel IDE software,which is then transferred to the microcontroller memory using burner hardware along with dedicated software.Once the code is stored in the microcontroller,its function remains accordance with the users program.
Advantages:
The device is very helpful for the blind people to go in a exact path without the help of others .The IR signal response for after the detection of obstacle is delayed by 0.2 seconds which is to be overcome.