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DIGITAL BOOK FOR THE BLIND PEOPLE
INTRODUCTION:
This project is based on VTU syllabus. The proposed system is based on ATMEL 89S52 µcontroller which is in our syllabus.
This project involves some of the software’s like
1. Embedded C for programming the application software to the microcontroller.
2. Protel schematic software is used for designing the circuit diagram for this project.
3. Express PCB software is used for designing the PCB for this project.
(Since PCB making is a big process and involves lot of machineries which are expensive, we are going to outsource this to the manufacturer.)
ABSTRACT:
Early days a blind person had to study by feeling the drilled holes in a metal book. This is a new book invented for the blind using the voice chip, microcontroller and speakers which enables a blind person to read /study the chapters by listening to the recorded message .The message recorded is stored in the voice chip. The blind person can access the pre-recorded messages using the four switches available on the board. Each switch performs a specific operation as specified i.e. PLAY/RECORD, REPEAT, STOP, and DOWN. The book also provides many facilities like play the desired message, play the entire location, play the desired message repeatedly as per the user’s convenience. It is also provided with an extra feature of recording the message at particular location or the entire memory.
TECHNOLOGY USED:
Voice chip (Record & Playback) technology
COMPONENTS:
1. Power Supply Standard Type 7805, 5V DC
2. Micro controller-AT89S52-Atmel (Atmel.Com)
3. LCD (Liquid Crystal Display) 16x2 characters
4. APR6016- VOICE IC
5. Buzzer. Freq-1 to 18 kHz (5v-12Vdc)
PERCENTAGE OF H/W AND S/W:
1. Embedded C : 50%
2. Microcontroller H/W : 50%
WORKING PRINCIPLE:
In this project the microcontroller acts as a master and the voice chip as a slave .The voice chip behaves according to the commands sent by the microcontroller. The protocol used for communication between the two I.C’s is S.P.I (Serial Peripheral Interface).
Initially the microcontroller sends a power up command to the voice chip which in turn activates the voice chip for further actions to be performed. The hardware has four switches performing different operations
From the ascending order the first switch is the PLAY/RECORD switch it performs two operations I.E once the jumper is connected across the port 1 pins then the voice chip enters the record mode else it is in the play mode.
The person can record/play the desired message (location) by pressing the down button. The DOWN switch is pressed the number of times the user wants to reach the particular memory. REPEAT switch once pressed enters repeat mode for one particular message and again .REPEAT switch pressed twice enters repeat mode for entire memory here DOWN switch becomes deactivated. STOP switch is used to stop the message play at any moment only when the message is in repeat mode.
The PLAY and RECORD operations are done by giving the respective commands to the VOICE CHIP .These commands are industry standards and hence used the same way ach command does a specific operation hence the commands are given with particular delay in-between and sent to the voice chip from microcontroller using SPI communication protocol.
Example-PLAY command-60000
RECORD Command-40000
STOP command-300000
PLAY: 0110 0000 0000 0000 0000 - the first 5 bits 01100 is the play command and the next 15 bits are Address bits. Overall each command has 20 bits.
SPI PROTOCOL:
1. Full-Duplex, 3-Wire Synchronous Data Transfer
2. MSB First Data Transfer
3. Four Programmable Bit Rates
4. End of Transmission Interrupt Flag
The SCK pin is the clock output in the master mode but is the clock input in the slave mode. Writing to the SPI data register of the master CPU starts the SPI clock generator, and the data written shifts out of the MOSI pin and into the MOSI pin of the slave CPU. After shifting one byte, the SPI clock generator stops, setting the end of transmission flag (SPIF). If both the SPI interrupt enable bit (SPIE) and the serial port interrupt enable bit (ES) are set, an interrupt is requested. The Slave Select input, SS/P1.4, is set low to select an individual SPI device as a slave. When SS/P1.4 is set high, the SPI port is deactivated and the MOSI/P1.5 pin can be used as an input.
OUR CHALLENGING WORK IN THIS PROJECT:
1. Design Voice chip interface circuit.
2. Write the program for the microcontroller using embedded ‘C’ for 8051.
3. Design LCD interface.
4. Design switch interface circuit.