Abstract- Now aday notice board has become an important thing in institutes/organization orpublic places like railway stations, bus stands and hospitals. But to use thepaper notices stacked on a notice board is a time taking and expensive processand there is wastage lot of time, paper and labour. The notice board is used todisplay the information in an effective way to the people, but to update themessages instantly is not easy on the notice board.

This project, deals aboutan advanced Hi-Tech wireless Notice Board. This system is enhanced to displaythe latest information through an Android application of smart phones or tabletwhich can be connected to Bluetooth (HC-05). At the receiver end a low cost microcontroller(arduino Uno) is programmed to receive and display messages in the LCDdisplay.  In order to display noticesuser can use the application to speak and then verbalized voice into text andclick on send button to get it displayed on LCD screen. In this project, we aregoing to develop an on-line speech-to-text engine. The system takes speech asinput through microphone and a sampled speech is processed to identify theverbalized text. Speech recognition is done via the Internet, connecting to Google’sserver. The application is adapted to input messages in English.

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Speechrecognition for Voice uses a technique based on hidden Markov models (HMM -Hidden Markov Model). It is the most successful and flexible approach forspeech recognition.   Keywords— LCD, HC-05, android, arduino Uno, HMM. I.  INTRODUCTION The idea behind voiceoperated electronic board exploits to point out the messages and regulate themby exploit our own voice. We have already used GSM primarily based Electronicboard, but speech controlled board has extra advantage. User needs to formulatecommand in his/her own voice to regulate the messages displayed on electronicboard 6.

User has to install automation applications in his/her smart phones,they are easy touse, promising and durable devices that help in performing day to daytasks,  voicerecognition is finished within the automaton application. Embeddedsystems using wireless technologies are widely used for communicating withperipheral devices. The GSM based wireless communication for differentapplications are implemented and proposed.

A simple low cost wireless androidbased notice board is developed and presented. This system uses a wirelessserial data communication in displaying messages on a remote digital noticeboard with Bluetooth connection. Bluetooth and Wi-Fi communication for personaldigital assistant (PDA) devices are used for transmitting the alpha-numerictext messages using Android based Application programs available for Using theBluetooth based serial data communication technique, the correspondingtransceiver module has been interfaced with microcontroller board at thereceiver end. For this purpose, a low cost microcontroller board (Arduino Uno)is programmed to receive alphanumeric text messages in the Bluetooth mode.

Theproposed system will reduces the resources like the human effort, paper,printer ink and cost for manual changing of the notices in the noticeboard. Bluetooth wireless technology is a technique within thecommunication arena, and it is one in all the quickest growing fields withinthe wireless technologies. Bluetooth technology handles the wireless a part ofthe communication channel; it is utilized in this project to transmit andreceive data between devices. Whereas, a phone is just quite a phone recently,it is good phone the quantity of applications being engineered on a good variesof platforms for smart phone is astounding. A computer system can be used as aspeech synthesizer and can be implemented in software or hardware products withan artificial production of human speech1. II.  COMPONENTS AND SYSTEM DESCRIPTIONAn Arm processor withdevelopment board, it is an arm development board which consists of 32-bitarm7tdmi-s microcontroller in a tiny lqfp64 package. The microcontroller in itis lpc2148.

There are LCD’s, a 2*16 alphanumeric LCD also available in thedevelopment board. Other than these are two uart, usb 2.0, jtag, vga, powerjack, buzzer, sd/mmc and buttons.  Androidapplication an application named home automation has been used to switch on/offdc motors using on/off button and another button for typing and sending a noticeto be displayed in the lcd as shown in the fig.

1. A 16*2 alphanumeric LCDdisplay has been used to display the notice sent by the authorised user. It isa 16*2 screen which means it can display 16 alphanumeric characters in eachline and there are two lines for display in total which sums upto a maximum of32 characters being displayed at a time. It has 8 data pins since eachcharacter is of 8 bits and three other pins namely, enable, read/write andregister select. Whenever the enable pin is low, LCD is off and it is on if thepin is high.

The read/write pin, if high, reads the data from LCD and if low,writes data in it. The register select pin decides the type of data transferredthrough the data pins. If it is high, a character iswritten in LCD and if low, command is sent to LCD.The simple and low-cost wireless Android basednotice board system is developed to remotely send the desired informationinstantly to the intended users using Bluetooth transceiver module interfaced with a low cost Arduino UNOmicrocontroller board.

The communication mode Bluetooth is selected for datacommunication using the corresponding transceiver module with themicrocontroller. Arduino UNO microcontroller board is programmed as a clientusing Arduino software to receive the message from remote user in Bluetoothbased wireless communication technology. An Adruino’smicrocontroller is also pre-programmed with a boot loader that simplifies uploading of programs to the on-chip flash memory, compared with other devices that typically need anexternal chip programmer. This makes using anArduino more straightforward by allowing the use of an ordinary computer as theprogrammer. Currently, opt boot boot loader is the default boot loaderinstalled on Arduino UNO. At a conceptual level, when using the Arduinointegrated development environment, all boards are programmed over a serialconnection. Its implementation varies with the hardware version.

A levelshifter circuit is used in the serial Arduino Boards which convertsbetween RS-232 logic levels and transistor–transistor logic (TTL) level signals5. A Universal serial Bus (USB),implemented using USB-to-serial adapter chips such as the FTDI FT232 in the current Arduino boards are programmed. A Unoboards substitutes the FTDI chip with a separate AVR chip containingUSB-to-serial firmware, which is reprogrammable via its own ICSP header. Othervariants, such as the Arduino Mini and the unofficial Boarduino, use adetachable USB-to-serial adapter board or cable, Bluetooth or other methods, the Arduino IDE standard AVR in-system programming (ISP)is used instead of a traditional microcontroller tools.

 I.       SYSTEM IMPLEMENTATIONThe Bluetooth wireless technologyis a Personal Area Networks (PANs) in the range between 10-15 meters. And ituses the 2.45 GHz frequency band for connection. A HC-05 Bluetooth module hasbeen interfaced with the microcontroller board (Arduino UNO) using serial communication.The module’s Media Access Control address isused by Android application program (Bluetooth Terminal) which allows only thisdevice to communicate with the Smartphone for controlling the external devices.The interconnection of Android PDA with the external Bluetooth devices likeHC-05 Bluetooth module, using Bluetooth terminal for transmitting or receivingthe data in form of hex or string. Using the smart phone based wireless noticeboard in Bluetooth communication mode the user can send the alphanumeric textmessage instantly once the connection is established between Android based PDAand Bluetooth device (HC-05).

The notice on the LCD display can be changed atany time by resending the new message from PDA using android applicationprogram that is Bluetooth technology. The new message will overwrite theprevious message making the system very simple and easy to use. Theimplementation of Android based wireless notice board using Bluetooth communicationis shown in Fig. 2 below.   Fig.2. Bluetooth Wireless notice board based on smart phonesVoice RecognitionActivity is start-up activity defined as launcher in AndroidManifest.

xml file.REQUEST_CODE is static integer variable, declared on the beginning of activityand used to confirm response when engine for speech recognition is started.REQUEST_CODE has positive value. Results of recognition are saved in variabledeclared as List View type.

  Method onCreate is called when activity is initiated. This is where the most initialization goes: setContentView(R.layout.voice_recognition) is used to inflate the user interface defined inres > layout > voice_recognition.

xml, and findViewById (int) toprogrammatically interact with widgets in the user interface. First it will check the mobile phone, on whichapplication is installed, has speech recognition facility. Package Manager isclass for retrieving various kinds of information related to the applicationpackages that are currently installed on the device. FunctiongetPackageManager() returns Package Manager Instance to find global package information. Usingthis class, we can detect if the phone has a possibility for speechrecognition. If a mobile device doesn’t have one of many Google’s applicationswhich integrate speech recognition, further work of this application Voice SMSwill be disabled and message on the screen will be “Recognizer not present”.Recognition process is done trough one of Google’s speech recognitionapplications. If recognition activity is present, user can start the speechrecognition by pressing on the button and thus launching startActivityForResult(Intent intent, intrequestCode).

Theapplication broadcast an intent that requests voice recognition by using methodstartActivityForResult(), which includes an extra parameter that specifies oneof two language models and intent.putExtra (Recognizer Intent) is defined.Thespeech recognition contains feature extraction and feature matching modules.The feature extraction module converts speech waveform to some type ofrepresentation for further analysis and processing, this extracted informationis known as feature vector. A front end module is used for converting voicesignal to feature vector by processing the signal. As shown in above blockdiagram input to front-end is noise free voice sample and output of it isfeature vector. An unidentified voice sample is scored against acoustic modelis obtained from extracted feature vector, a hypothetical description with maxscore wins, and its output is considered as recognized word is done by featurematching.

Following are the few methods for implementing front-end (forextracting feature factor) as shown in fig.3. •MFCC (Mel-Frequency Cepstrum Coincident): A form of the short-term power spectrum of a sound, based on a linear cosine transform of a log power spectrum on a nonlinear mel scale offrequency is known as mel-frequency cepstrum (MFC). Mel-frequency cepstralcoefficients (MFCCs) are coefficients that collectively make up anMFC.They are derived from a type of cepstral representationof the audio clip (a nonlinear “spectrum-of-a-spectrum”) • LPC (Linear Predictive Coding) Once thefeature vector are obtained we build the acoustic model. The acoustic model isused to score the unknown voice sample. The obtained output of front-end isgiven as a input to the acoustic model which is shown in the block diagram.Different types of acoustic model are • VQ-Code Book 1 • GMM-Gaussian Mixture Model Acoustic Model Representation:In speech recognition, basic unit of sound is phoneme.

Phoneme is a minimalunit that serves to distinguish between meanings of words. For example sequenceof phoneme for “CAT” is K A and T. In English language there are nearly around46 phonemes.

We can construct any word from English dictionary using properconcatenation of this phoneme. A given word is recognized, a phoneme from voicesample is extracted.   Fig.4.

Data flowdiagram LCD initialization: Forinitialization, the pins R/W is kept low (write), RS is kept low (commandregister selected) and then command is sent through the 4-bit mode. But toplace the command into command register, E pin is transitioned from high to loweach time a byte is sent to the LCD. The commands sent for initialization inhexadecimal are, 28H, 20H, 06H, 01H and 80H. 2) Sending data to LCD: Sending ofdata involves following steps: • R/w is set low (write operation selected). •RS is set high (data register selected). • The data byte is sent through the 4data lines.

• E pin is transitioned from high to low for data to be placed intodata register. • The above steps are repeated to send other bytes of data. Advantages1) Notice board with wireless is easy toinstall and use without wasting any resources.2) It is really helpful for disabled orhandicapped people so that they can only speak and same is displayed on LCDscreen.3) It will reduce the use of resourceslike paper and pen and hence deforestation can be turned into aforestation. IV.

CONCLUSION By introducing the concept of wireless technology inthe Field of the communication we can make our communication more efficient andfaster, with greater efficiency. We have developed a voice control Bluetoothwireless android application for a notice board which will display the messageswith less errors and maintenance. And this system can be used in colleges,school, offices, railway station and commercial as well as personal used whichreduces the use of a resources like pen, paper etc. In future we can apply thismethod for remote teaching classes.