The goal of the Blind Aid project is to develop navigational assistance technology for the blind or visually impaired. Specifically, we seek to develop a portable Electronic Travel Aid (ETA) for visually impaired users, along with the accompanying radio frequency identification (RFID) localization infrastructure used to equip buildings. The major problem the visually impaired experience is trouble with indoor navigation in unfamiliar buildings. Imagine the wide open spaces in an airport concourse; even if there are Braille signs at the counters, the blind may not be able to find them. Blind people use moving ramps, escalators, revolving doors, and turnstiles with as much ease as any sighted person. When encountering stairs, it simply isn't necessary to explore each step. The cane tip is used primarily to detect the beginnings and ends of stairways. In either case, it is a good idea to hold the cane in a manner that would not trip a fellow pedestrian. One of the major goals for blind and visually impaired people is independent mobility. Mobility aids like walking sticks and guide dogs are commonly used by the blind even today. With the advances of modern technologies, many different types of devices are available to support the mobility of the blind. These mobility aids are generally known as electronic travel aid. Methodology: This project is developed for the blinds to find out the location of the place where they are. The main modules in this project are Zigbee, ARM controller unit, and Voice signal as an output. The transmitter will be there with a blind and the receiver will be there at the location. The transmitter module has Switches, an ARM controller, and Zigbee as a communication media. The receiver has Zigbee, an ARM controller, and a voice-operated device. If a Blind Presses a Switch to know the location, that information will be given to the ARM controller, then the ARM controller analyses the signal and sends information to the receiver which is present in the location via Zigbee. At the receiver, the Zigbee receives a signal which was transmitted from the transmitter and sends that to the ARM controller. After receiving the signal the ARM controller will activate the proper voice chip to provide a corresponding voice signal. Advantages: 1. Secure and reliable communication. 2. Leading-edge technology that meets today's and tomorrow's needs. 3. This not only detects the obstacles but can also guide the user around them. This combination of obstacle detection and avoidance reduces the conscious effort required from the user. 4. Continuous scanning of the environment relieves the user from additional actions, therefore reducing the required physical and mental effort. 5. This can provide the user with a panoramic view of the environment, covering a sector of 120 degrees. Disadvantages: 1. One-time investment cost. 2. It has to be planted throughout the city.

1. 2. Travel Assistant for the Blind with Dynamic User Input For
Location-Based Alerts Using ARM7 And Zigbee
Introduction:
The goal of the Blind Aid project is to develop navigational assistance technology for the
blind or visually impaired. Specifically, we seek to develop a portable Electronic Travel Aid
(ETA) for visually impaired users, along with the accompanying radio frequency identification
(RFID) localization infrastructure used to equip buildings.
The major problem the visually impaired experience is trouble with indoor navigation in
unfamiliar buildings. Imagine the wide open spaces in an airport concourse; even if there are
Braille signs at the counters, the blind may not be able to find them.
Blind people use moving ramps, escalators, revolving doors, and turnstiles with as much
ease as any sighted person. When encountering stairs, it simply isn't necessary to explore each
step. The cane tip is used primarily to detect the beginnings and ends of stairways. In either case,
it is a good idea to hold the cane in a manner that would not trip a fellow pedestrian.
One of the major goals for blind and visually impaired people is independent mobility.
Mobility aids like walking sticks and guide dogs are commonly used by the blind even today.
With the advances of modern technologies, many different types of devices are available to
support the mobility of the blind. These mobility aids are generally known as electronic travel
aid.

2. Block Diagram:
LOCATION INFORMATION TRANSMITTER
RECEIVER STAGE
GND
LCD DISPLAY
HARDWARE REQUIREMENTS: ARM 7 / Cortex M3, LCD, Relay Driver, Relays, Resistors, Capacitors, LEDs, Crystal, Diodes, Transformer, Voltage Regulator,
Push Button.
SOFTWARE REQUIREMENTS: Keil compiler uVision 4, Language: Embedded C or Assembly, WLPRO Programmer
230 V, AC
Supply
TRANSFORMER RECTIFIER FILTER REGULATOR
+12 Volts
+5 Volts
XBEE TX ARM PROCESSOR
KEY INPUTS

3. Receiver:
BUFFER DRIVER RELAY
LCD DISPLAY
ARM PROCESSOR
OR
OR
M
VISUAL
INDICATION
VOICE
DC MOTOR
OUTPUT DEVICES
XBEE RX

4. Block diagram explanation
Power supply unit
This section needs two voltages viz., +12 V & +5 V, as working voltages. Hence
specially designed power supply is constructed to get regulated power supplies.
Switches:
In electrical engineering, a switch is an electrical component that can break
an electrical circuit, interrupting the current or diverting it from one conductor to another. A
switch may be directly manipulated by a human as a control signal to a system.
Automatically operated switches can be used to control the motions of machines.
ARM processor
ARM is a computer processor-based RISC architecture. A RISC-based
computer design approach means ARM processors require significantly fewer
transistors than typical processors in average computers. This approach reduces costs,
heat, and power use. The low power consumption of ARM processors has made them
very popular:
The ARM architecture (32-bit) is the most widely used in mobile devices, and
the most popular 32-bit one in embedded systems.
Zigbee Technology
ZigBee is a specification for a suite of high-level communication protocols used to
create personal area networks built from small, low-power digital radios. ZigBee is based on
an IEEE 802.15 standard. Though low-powered, ZigBee devices can transmit data over long
distances by passing data through intermediate devices to reach more distant ones, creating
a mesh network.
Buffers

5. Buffers do not affect the logical state of a digital signal (i.e. a logic 1 input results in a
logic 1 output whereas logic 0 input results in a logic 0 output). Buffers are normally used to
provide extra current drive at the output but can also be used to regularize the logic present at
an interface
Drivers
This section is used to drive the relay where the output is the complement of input
which is applied to the drive but the current will be amplified
Relays
It is an electromagnetic device that is used to drive the load connected across the
relay and the o/p of the relay can be connected to the controller or load for further
processing.
Voice recorder:
The aPR33A series are powerful audio processors along with high-performance
audio analog-to-digital converters (ADCs) and digital-to-analog converters (DACs). The
aPR33A series is a fully integrated solution offering high performance and unparalleled
integration with analog input, digital processing, and analog output functionality. High-
quality audio/voice systems with lower bill-of-material costs can be implemented with
the aPR33A series because of its integrated analog data converters and a full suite of
quality-enhancing features such as sample-rate converters.
In this messages must be recorded or played back sequentially, specially designed
for simple key triggers, the user can record and playback the message. Meanwhile, this
mode provides a power-management system.

6. DC motor:
A DC motor relies on the fact that magnet poles repel and unlike magnetic poles
attract each other. A coil of wire with a current running through it generates
an electromagnetic field aligned with the center of the coil. By switching the current on or off
in a coil its magnetic field can be switched on or off or by switching the direction of the
current in the coil the direction of the generated magnetic field can be switched 180°.
Indicator:
This stage provides a visual indication of which relay is actuated and deactivated,
by glowing respective LED or Buzzer.
Methodology:
This project is developed for the blinds to find out the location of the place where
they are. The main modules in this project are Zigbee, ARM controller unit, and Voice signal
as an output.
The transmitter will be there with a blind and the receiver will be there at the location.
The transmitter module has Switches, an ARM controller, and Zigbee as a communication
media. The receiver has Zigbee, an ARM controller, and a voice-operated device. If a Blind
Presses a Switch to know the location, that information will be given to the ARM controller,
then the ARM controller analyses the signal and sends information to the receiver which is
present in the location via Zigbee. At the receiver, the Zigbee receives a signal which was
transmitted from the transmitter and sends that to the ARM controller. After receiving the
signal the ARM controller will activate the proper voice chip to provide a corresponding
voice signal.

7. Advantages:
1. Secure and reliable communication.
2. Leading-edge technology that meets today's and tomorrow's needs.
3. This not only detects the obstacles but can also guide the user around them. This
combination of obstacle detection and avoidance reduces the conscious effort
required from the user.
4. Continuous scanning of the environment relieves the user from additional actions,
therefore reducing the required physical and mental effort.
5. This can provide the user with a panoramic view of the environment, covering a
sector of 120 degrees.
Disadvantages:
1. One-time investment cost.
2. It has to be planted throughout the city.
Applications:
1. This project can be implemented to increase the independent mobility of blind and
elderly travelers
2. Restricted zones.
3. Wherever mobility is important there we can implement this project.