POINT TO POINT VOICE COMMUNICAION SYSTEM FOR REMOTE AREAS
Introduction
This project is
designed for the point to point voice communication in remote areas. We are
using 2051 microcontroller which is 20 pin IC.
The project uses APR9600 sound recorder IC for
recording the voice. This IC can record speech up to 60 sec using a mike in
five modes:
1.
Random access 2 fix
mode
2.
Random access 4 fix
mode
3.
Random access 8 fix
mode
4.
Tape Mode auto
rewind operation
5.
Tape Mode normal
operation
The circuit for each
mode is different. The voice signal can be retrieved by a speaker.
The controller is
used to control over the voice recording in recorder IC, The controller also
controls over transmitting the signals.
The signals will be
transferred to the remote receiver by a radio transmitter.
Scope of the project
This project can be
used for making sound recorder for any radio device. At big level this project
can be used pre-recorded sound signaling for telecommunication.
Block Diagram
HARDWARE USED
1.
ATMEL AT89C8051 ยตc
2.
APLUS APR9600 sound recorder IC
3.
General purpose PCBs
4.
Speaker
5.
Mike
SOFTWARE USED
KEIL Compiler
Brief description of AT89C2051
Specification
·
It is 20 pin version of 8051 microprocessor
·
It is 8 bit microprocessor
·
2 Kbyte flash programmable erasable ROM
·
Manufacturer is ATMEL
·
15 Programmable I/O
Lines
·
Two 16-bit
Timer/Counters
·
Six Interrupt
Sources
·
Direct LED
Drive Outputs
·
On-chip Analog
Comparator
·
can be programmed using the MCS-51 instruction set
· contains
128 bytes of internal data memory (RAM)
· On chip oscillator and clock circuitry
Brief
Description of APR9600
Specification
·
Manufacturer is APLUS
· It is 28 pin IC
· It can record speech up to 60 Sec in five
modes
· Each slot of the speech can be retrieved
separately
· The incoming voice signals are sampled and
the instantaneous voltage samples are stored in the non-volatile flash memory
cells in 8-bit binary encoded format.
· During playback, the stored signals are
retrieved from the memory.
· An
internal oscillator provides sampling clock to the APR9600.
· Higher sampling rates improve the voice
quality but they also increase the bandwidth requirement and thus reduce the
duration. Lower sampling rates use fewer memories.
Conclusion
Use of both the ICs APR9600 and AT89C2051
help in power and space saving. As microcontroller IC is a 20 pin IC and by
using APR9600 we does not need to use any other IC for making record.
Our proposed design will be a low cost low
power end to end prerecorded voice messaging system.
