Voice Controlled Switch System With Microcontroller Information Technology Essay

This undertaking is to plan an voice-controlled system, which can be achieved to an commercially valued application and extend in varies fields.The system will split to three subdivisions, First, detection of input voice and change over it to 8 spots digital signal via AD convertor, Second, digital signal transimit to microcontroller and than stored in memory.After that, when voice input come in, microcontroller will acknowledge that if it ‘s the same signal from the fisrt one, and so it will give mentioning bid to controller.Controller receive commend will reflect the specified action, like, if the system receive right signal, LED lamp will be shown green, LCD announced by ” Beryllium ALLOWED ” besiedes, the digital switch will automatical open.Otherwise, all devices will give an opposite reaction for rejected response.The accomplishment of this undertaking will take low cost and derive more benefit for its drawn-out application, people can use it for specified demand that makes life more convenient and easier.

In presents day-to-day life, automatic controlled system are applied in different ways to carry through of people ‘s need.But it still exists many hidden jobs behind those applications.Like the automatical door based on infrared system.I conjecture person might run into the undermentioned state of affairss, the automatical door which is several centimetres in forepart of you is still closed when you are in haste for traveling in or out of the edifice, therefore you have to be one measure back and so, seek it again.In to boot, person might happen it will automatical open when person goes by it instand of traveling through it.Therefore, we want to plan a application which can do automatical system be maximal efficiency.As we know different people owns different characters, like voice, fingerprint and so on, and those characters are all “ hand-free ” input information, which will be meaningful for “ automatical controlled ” merchandises. So we wondered if there exists an system, based on people ‘s charactors, which have really high truth to acknowledge and give respond reaction in low cost.So we made up an illustration that use an specified voice as input to prove and verify if it ‘s possible to be an high truth application, therefore, we can widen this with existent voice of people for automatical merchandises in the hereafter.

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1.2System Description:

The Our system will obey to the normal control system ‘s structure.The general flow-chart will be as follows: Fig.1 System Block Diagram.

II. Materials and methods

2.1voice ‘s input and amplifier.

The system Begin with the voice bid which be compled by C programming linguistic communication, so it will be distributing as an input signal first clip and received by conveying detector I/O, mike processed voice to analog signal and outputting it to amplifier Vt1. This elaboration will hold a guard-leg connexion [ 1 ] to supply common – manner perturbation and do the parallel signal bettering its signal-to-noise ratio ratio.

Fig1.Amplifier ( voice-mic-amplifier )

2.2 band-pass filter

The processed parallel signal so as an input transmitted to band-pass filter. [ 2 ] When analofg signal passed through bandpass filter, it can be limited for its spectral frequency.Assume that original voice settled between 500-1200Hz, in hence, the filtered signal will be multipled by an sensor and protecting frequences like amount and difference frequences from the original signal.Thus those amounts or diff frequence will be belongings for the original voice, since so, those signal will be foremost memorized by microcontroller as sample and detected when the same voice transmitted into system.This measure is an really efficient manner to obtain the utile signal which is mentioning the specified original voice with characters and avoid noise which improves truth of system. [ 3 ]

Fig2.Band base on balls filter

2.3A/D converter

Analog input signal via A / D convertor will change over to mentioning 8-digit Numberss establishing on our scheduling here, as the digital signal for outputting. Generally, A / D faculty has high or low mention electromotive force input, which is the package of pick available VDD, VSS, RA2 or RA3 combination.Therefore, this measure can really coding the character signal with high efficiency and so those character codifications will be used in transmittal fuctions for following measure. [ 4 ]

Fig.3 A/D convertor.

2.4Microcontroller ( PIC16F887 )

The PIC architecture is distinctively minimalist. It is characterized by the undermentioned characteristics:

Separate codification and informations infinites ( Harvard architecture )

A little figure of fixed length instructions

Most instructions are individual rhythm executing ( 4 clock rhythms ) , with individual hold rhythms upon subdivisions and skips A individual ( W ) , the usage of which ( as beginning operand ) is implied ( i.e. is notencoded in the opcode )

All RAM locations map as registries as both beginning and/or finish of math and other functions.A hardware stack for hive awaying return addresses A reasonably little sum of addressable informations infinite ( typically 256 bytes ) , extended through banking

Data infinite mapped CPU, port, and peripheral registries The plan counter is besides mapped into the informations infinite and writable ( this is used to implement indirect leaps ) .

In this plan, the map of the Microcontroller is an hub for whole system, we can it can be described as the following flow chart. [ 5 ]

Fig.Block diagram contains Pic F887, LED, LCD, Switch

As the parametric quantity we get from Pic16F887 data sheet [ 6 ] , Program Memory A for it is 14KB, it ca n’t be approach by input and shop so much clip to recognize.So this is why we merely use one specified short voice as sample.In microcontroller bit, our responsibility is to roll up all commends for old and following measure, here we use Hundred linguistic communication to roll up.

2.5 LCD

To accomplish LCD successes executing, we use declaration here to manage parallel signal.The signal normally be stored in binary signifier, which represent that unit of declaration is in bits.And it can be expressed with 2n as it value.So LCD here receive commend from microcontroller, and it will work as what we programme.And the same look ways like digit 1 refer to “ off ” and digit 0 represent “ on ” .For illustration, when we want to show parallel 1, it will be 1001 1111

Fig. LCD show.

2.6 LED and exchange

As the controlled system diagram show, I made LED and Switch with same bomber overseas telegram, and the switch which is with the green visible radiation will work about at the same time.It will non be demands here to execute both of them from their user manual.The merely thing here is for the package work which is compile 8 figures commends in case* status of C scheduling.

Fig.condition of LED ( Typical LED requires a DC current of about 10 mas. ) [ 7 ]

III. Consequences


Fig.circuit diagram


After test both circuit and programming language.The whole will get down to work with specified voice, and we will reiterate the trial for several times to see the successed ratio and accuracy.as the theoretical assuming, we can acquire the undermentioned signal changement if we observe every measure from oscilloscop.

IV. Decisions

The consequence will be shown as the theoretical moving ridge expressed, merely small measurement mistake from the figure.Thus, we can turn out that the control system with “ voice ” variable is absolute available to widen its characters and it will be hold widely prospect for market ‘s demand.

And if repetition this experiment with different input specified voice in frequence, we suppose to obtain a decision that it might derive higher truth when the frequence of samples voices is comparatively higher compared with the nature environment, because of higher frequence will take to less noise input to system with sampled voice.Thus, voice with high quality can be encoded with little measure infomation. ,

The system shows tonss of advantages in facet of good consequence of testing.As a fact, it can be researched for unspecified-voice tool which used for varies of elctronical devices, for illustration, autos “ commanding for private usage, and machines for public industrial utilizing.Those electronical merchandises are all can be controlled without any computing machine or “ hand-hoding ” switch.

Simlarly, it can be extended to much deeper idea if the engineering for high-accuracy-human voice recognization can be successes execute, that must take an revolution with large measure frontward to engineering.

Besides, this system has a absolute adventage for its low cost belongings compared with other automatical system.And high truth recognize/response improves its public presentation for consumers.Compared with similar merchandises, like magnetical card for swith, they are easy losing, demagnetizing, and we have to take them anytime, anyplace. “ Low cost, high public presentation and hand-free ” do voice-controlled additions more makings for competition.

Howerver, this simples systems still have many disadvantages to enhance.Its stableness is a large job, for if input sound are with really low frequence, it will additions much noise for the system, which can non be avoid for all even utilizing filters.And the overseas telegrams of the existent merchandises for security automatical doors, have to be buried outside of the door.Which can be easy broken by unknown factors.

After all, the voice-controlled system still ain possible belongings to widen if all jobs above can be fixed in a great manner.




[ 1 ] Chuanyou Sun, Xiaobing Sun, Shengyu Li, Yi Zhang, Control circuit and settlement,1st edtion, May 2002, pp 18.

[ 2 ] Chuanyou Sun, Xiaobing Sun, Shengyu Li, Yi Zhang, Control circuit and settlement,1st edtion, May 2002, pp 35.

[ 3 ] Robert A.Valley, Method and setup for detectinf the presence of human voice signal in audio signals, Oct 10,1995, Patent number:5457769

[ 4 ] Akira Ichikawa, Musashino with his spouses, Character voice communicating system, Dec 4,1990, Patent Number:4975957


Bradley University Electrical Engineering Department, April 27, 2004

[ 6 ] PIC16F887, Data sheet, Microchip.

[ 7 ] C.J.Dadson, Specification and usage of light breathing diodes,10th Aug,1998.