07-05-2011, 11:39 AM
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PROJECT DESCRIPTION
In this project we will use a stck for bind person with ultrasonic sensors. We will use ultrasonic sensors for distance measurement and also will use a voice processor. In this project we are using ultrasonic sensors of two types
1) Transmitter
2) Receiver
When a blind person going on the road and a then any type of object will come then ultrasonic sensors measure the distance firstly and then a voice will be come from voice processor like ”object is near”. The project Ultrasonic trblind stick is a very interesting and useful project for many industrial applications. In this project we have used the ultrasonic waves to measure the distance in between two points. The basic principal is based on the speed of ultrasonic waves in open air. We have used a microcontroller AT89S51 to transmit and receive ultrasonic waves through 40 KHz ultrasonic receiver and transmitters. By measuring the time required to travel the unknown distance by ultrasonic waves in air we can find out the distance between two points. The distance measured is displayed on a LCD display. The transmission & reception of ultrasonic waves is very complex in nature so it needs very sophisticated techniques to process these waves. We have used a very complex structure of amplifier and filters for this purpose. The speed of ultrasonic waves is dependent on temperature. So before using ultrasonic waves for any measurement we need to calibrate the speed of ultrasonic waves in current atmospheric temperature. For this purpose we have implemented a special algorithm to calibrate the speed of ultrasonic waves through a known distance of 100 Cm.
There are numerous applications of ultrasonic waves in instrumentation and control. These applications include measurement of distance, speed, flow etc. Ultrasonic also find many application in medical instrumentation.
Voice processor
Single-Chip Voice Recording & Playback Device
60-Second Duration
Features
• Single-chip, high-quality voice recording & playback
solution
- No external ICs required
- Minimum external components
• Non-volatile Flash memory technology
- No battery backup required
• User-Selectable messaging options
- Random access of multiple fixed-duration messages
- Sequential access of multiple variable-duration
messages
• User-friendly, easy-to-use operation
- Programming & development systems not required
- Level-activated recording & edge-activated play
back switches
• Low power consumption
- Operating current: 25 mA typical
- Standby current: 1 uA typical
- Automatic power-down
• Chip Enable pin for simple message expansion
General Description
The APR9600 devi ce offers true single-chip voice recording,
non-volatile storage, and playback capability for 40 to 60 seconds.
The device supports both random and sequential
access of multiple messages. Sample rates are user-selectable,
allowing designers to customize their design for unique
quality and storage time needs. Integrated output amplifier,
microphone amplifier, and AGC circuits greatlysi
mplify system design. the device is ideal for use in portable voice
recorders, toys, and many other consumer and industrial
applications.APLUS integrated achieves these high levels of storage capabilityby using its proprietary analog/multilevel storage technology
implem ented in an advanced Flash non-volatile
memory process, where each memory cell can store 256 voltage
levels. This technology enables the APR9600 device to
reproduce voice signals in their natural form. It eliminates the
need for encoding and compression, which often introduce
distortion.
