秋霞电影新入口

秋霞电影新入口A Shaastra Circuit Design Challenge blog!

Wednesday, 16 October 2013

Electronically guided walking stick for the blind.

Mobility for the blind is always a great problem. Just like a sighted, blind also needs to travel around inside
a closed premises like house, factory, office, school etc. They may also like to go for shopping, visiting friends and other places of their interest Presently available electronic travelling aids like sonic path finder, sonic torch etc. are not suitable for using inside a closed premises such as school, factory, office etc.

Blind since old age have been using walking stick for their mobility purposes. In addition some of them are also using guide-dog for their mobility. Due to the development of modern technologies, many different types of devices are available to assist the blind. They are commonly known as electronic travel aid. Many of these travelling aids use either ultrasound or laser beam. One of such devices is the laser cane that is similar to a long cane with built-in laser ranging facilities. But most of the commonly used electronic travelling aids use ultrasound for functioning. These devices use the reflectance property of the high frequency ultrasound and are available in different models such as:


A. Sonic torch
It is battery operated and is about the size of a large electric torch. It is a hand held device and operates on the principle of transmitting ultrasound in the forward direction and receiving the reflected beam from a nearby object.


B. Mowat sensor
It is a light weight,'hand held, pocket size device and is quite similar to a common torch that is used by the sighted people. It can detect object by sending high frequency ultrasound in pulses and receiving the reflected beam from any nearby object. User can identify the distance of the object by the rate of vibration that is produced by the device.


C. Sonic pathfinder
Like a Mowat sensor a sonic pathfinders also identify an object by receiving the reflected ultrasound that is emitted by the device. But unlike Mowat sensor which is a hand held device a sonic pathfinder is to be fitted on the head of the user. The audio output from the sonic pathfinder is made up of notes of a musical scale which produce a familiar tonal progression as the user approaches an object, is fed to the user through earphones.

Problem Statement And TDP for SCDC-SHAASTRA-2014 Has Been Released

Check out Problem Statement and TDP for SCDC-SHAASTRA-2014 in this link:

Voice Controlled Electronic Switches

Speaker Dependent / Speaker Independent

Speech recognition is classified into two categories, speaker dependent and speaker independent.Speaker dependent systems are trained by the individual who will be using the system. These systems are capable of achieving a high command count and better than 95% accuracy for word recognition. The drawback to this approach is that the system only responds accurately only to the individual who trained the system. This is the most common approach employed in software for personal computers.Speaker independent is a system trained to respond to a word regardless of who speaks. Therefore the system must respond to a large variety of speech patterns, inflections and enunciation's of the target word. The command word count is usually lower than the speaker dependent however high accuracy can still be maintain within processing limits. Industrial requirements more often need speaker independent voice systems, such as the AT&T system used in the telephone systems.

Recognition Style

Speech recognition systems have another constraint concerning the style of speech they can recognize. They are three styles of speech: isolated, connected and continuous.Isolated speech recognition systems can just handle words that are spoken separately. This is the most common speech recognition systems available today. The user must pause between each word or command spoken. The speech recognition circuit is set up to identify isolated words of .96 second lengths.Connected is a half way point between isolated word and continuous speech recognition. Allows users to speak multiple words. The HM2007 can be set up to identify words or phrases 1.92 seconds in length. This reduces the word recognition vocabulary number to 20.Continuous is the natural conversational speech we are use to in everyday life. It is extremely difficult for a recognizer to shift through the text as the word tend to merge together. For instance, "Hi, how are you doing?" sounds like "Hi,.howyadoin" Continuous speech recognition systems are on the market and are under continual development.

Speech Recognition Software

Do you make time to talk to your Arduino? Maybe you should! The EasyVR Shield is a voice recognition shield for Arduino boards integrating an EasyVR module. It includes all of the features of the EasyVR module in a shield form factor that simplifies connection to the Arduino main board and PC.EasyVR is a multi-purpose speech recognition module designed to add versatile, robust and cost effective speech and voice recognition capabilities to virtually any application. EasyVR is the second generation version of the successful VRbot module and builds on the features and functionality of its predecessor. In addition to the EasyVR features like 32 user-defined Speaker Dependent (SD) triggers and a host of built-in speaker independent (SI) commands, the shield has additional connectors for the microphone input, an 8 ohm speaker output, audio line-out/headphone jack, and access to the I/O pins of the EasyVR module. A programmable LED is also included to show feedback during recognition tasks.A simple and robust serial protocol (9600 8-N-1 default) can be used to access these functions from the Arduino board. Check out the video below of the EasyVR Shield being used to control a servo motor.You may refer to this video for a demo on EasyVR Shield for Arduino:

Thursday, 30 May 2013

Digital to Analog Conversion (DAC) using a Resistor Ladder

Following is a good way of implementing a DAC using a resistor ladder:

Courtesy: Texas Instruments Facebook Page

Monday, 8 October 2012

TDP TEMPLATE RELEASED!!

The TDP template for this years SCDC for Shaastra 2013 has been released. Please check out the same at http://www.shaastra.org/2013/main/#events/scdc

Tuesday, 2 October 2012

SCDC 2012

The problem statement is now released.
Visit  the Shaastra Website for the problem statement..

TDP format will be released shortly.