20-04-2012, 03:31 PM
Voice Interactive System
[attachment=20460]
INTRODUCTION
The usage of computer based systems for information interchange has been quite a common practice. Automation of every institution is a general requirement now a day. This project is meant for automating a college .IVRS is a generic term applications that integrate a company organizations telephone and computer system to become a voice computer that transforms the caller’s telephone into a terminal capable of directly accessing information and services .IVRS allows the publishing of database information through an interface technology combining computer telephony hardware and software. IVRS is an interactive manner. It allows a person to ask questions and provide answers by just pressing keys on their touch tones on the phones.
MICROCONTROLLER- PIC16F7X
The PIC16F7X is a low-power, high-performance CMOS 16-bit microcomputer with 4K bytes of Flash programmable and electrically erasable programmable read-only memory (EEPROM). PIC16F73/76 devices are available only in 28-pin packages. The 28-pin devices have 3 I/O ports.The microcontroller receives the signals from DTMF decoder and ring detector and passes to the PC and gives out the apt responses required. The responses are passed onto the caller for the proper informative working of the system.
DTMF DECODER
The MT8870D/MT8870D-1 is a complete DTMF receiver integrating both the band split filter and digital decoder functions. The filter section uses switched capacitor techniques for high and low group filters; the decoder uses digital counting techniques to detect and decode all 16 DTMF tone pairs into a 4-bit code. This portion of the circuit is mainly meant for identifying the choice of the caller. The caller is connected to the system. The options are facilities available are detailed to the caller and he/ she can choose his requirement by pressing the keys on the touch pad of the phone from which he is calling. DTMF decoder is kept in the circuit to identify the choice of the caller. The analog key signal pressed would be converted into digital format and the output of this section will be the binary representation of the keys pressed by the caller.
RING DETECTOR
This section identifies the incoming ring and notifies the microcontroller. A capacitor is used to block any DC voltage coming from the telephone line. The diodes prevent the reversal of polarity of the incoming signal. In the absence of any ring, the output of the ring detector will be in high state and when a ring comes, it goes to the low state. The output of ring generator is fed directly to the microcontroller interrupt pin for identifying the incoming calls. 4N35 opto coupler is used here. Its a six pin IC, with a LED and a transistor in the internal circuitry.
SERIAL PORT
Establishing a direct connection between microcontroller and personal computer is not possible. It is mainly due to the difference in the voltage levels of both the systems. In order to avoid this and properly interface these systems, a serial port is used. The port used here is MAX 232 port. The output of this port is directly fed to 9-pin RS232 connector of the PC. The MAX232 is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5-V supply. Each receiver converts TIA/EIA-232-F inputs to 5-V TTL/CMOS levels. These receivers have a typical threshold of 1.3 V, a typical hysteresis of 0.5 V, and can accept ±30-V inputs. Each driver converts TTL/CMOS input levels into TIA/EIA-232-F levels. The driver, receiver, and voltage-generator functions are available as cells in the Texas Instruments Lin ASIC library.
PERSONAL COMPUTER
The data required for automation process are stored in the computer. The PC is programmed using Visual Basic. The necessary data is provided as output when the requirement is shown by the microcontroller to the PC. The telephone receiver is kept near to the PC speaker so that output is correctly fed back.
ON/OFF HOOK
A telephone hook or switch hook is the cradle where a telephone handset resides. It takes its name from old wooden wall telephones and candlestick telephones, where the mouthpiece to be mounted on the telephone box and, due to side tone considerations, the receiver was separate, on a cable. When the telephone was not in use, the receiver was hung on a spring-loaded hook; its weight would cause the hook to swing down and open an electrical contact, disconnecting the telephone from the line. When the handset is on the cradle, the telephone is said to be "on-hook", or ready for a call. When the handset is off the cradle, the telephone is said to be "off-hook", or unable to receive any (further) calls.
[attachment=20460]
INTRODUCTION
The usage of computer based systems for information interchange has been quite a common practice. Automation of every institution is a general requirement now a day. This project is meant for automating a college .IVRS is a generic term applications that integrate a company organizations telephone and computer system to become a voice computer that transforms the caller’s telephone into a terminal capable of directly accessing information and services .IVRS allows the publishing of database information through an interface technology combining computer telephony hardware and software. IVRS is an interactive manner. It allows a person to ask questions and provide answers by just pressing keys on their touch tones on the phones.
MICROCONTROLLER- PIC16F7X
The PIC16F7X is a low-power, high-performance CMOS 16-bit microcomputer with 4K bytes of Flash programmable and electrically erasable programmable read-only memory (EEPROM). PIC16F73/76 devices are available only in 28-pin packages. The 28-pin devices have 3 I/O ports.The microcontroller receives the signals from DTMF decoder and ring detector and passes to the PC and gives out the apt responses required. The responses are passed onto the caller for the proper informative working of the system.
DTMF DECODER
The MT8870D/MT8870D-1 is a complete DTMF receiver integrating both the band split filter and digital decoder functions. The filter section uses switched capacitor techniques for high and low group filters; the decoder uses digital counting techniques to detect and decode all 16 DTMF tone pairs into a 4-bit code. This portion of the circuit is mainly meant for identifying the choice of the caller. The caller is connected to the system. The options are facilities available are detailed to the caller and he/ she can choose his requirement by pressing the keys on the touch pad of the phone from which he is calling. DTMF decoder is kept in the circuit to identify the choice of the caller. The analog key signal pressed would be converted into digital format and the output of this section will be the binary representation of the keys pressed by the caller.
RING DETECTOR
This section identifies the incoming ring and notifies the microcontroller. A capacitor is used to block any DC voltage coming from the telephone line. The diodes prevent the reversal of polarity of the incoming signal. In the absence of any ring, the output of the ring detector will be in high state and when a ring comes, it goes to the low state. The output of ring generator is fed directly to the microcontroller interrupt pin for identifying the incoming calls. 4N35 opto coupler is used here. Its a six pin IC, with a LED and a transistor in the internal circuitry.
SERIAL PORT
Establishing a direct connection between microcontroller and personal computer is not possible. It is mainly due to the difference in the voltage levels of both the systems. In order to avoid this and properly interface these systems, a serial port is used. The port used here is MAX 232 port. The output of this port is directly fed to 9-pin RS232 connector of the PC. The MAX232 is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5-V supply. Each receiver converts TIA/EIA-232-F inputs to 5-V TTL/CMOS levels. These receivers have a typical threshold of 1.3 V, a typical hysteresis of 0.5 V, and can accept ±30-V inputs. Each driver converts TTL/CMOS input levels into TIA/EIA-232-F levels. The driver, receiver, and voltage-generator functions are available as cells in the Texas Instruments Lin ASIC library.
PERSONAL COMPUTER
The data required for automation process are stored in the computer. The PC is programmed using Visual Basic. The necessary data is provided as output when the requirement is shown by the microcontroller to the PC. The telephone receiver is kept near to the PC speaker so that output is correctly fed back.
ON/OFF HOOK
A telephone hook or switch hook is the cradle where a telephone handset resides. It takes its name from old wooden wall telephones and candlestick telephones, where the mouthpiece to be mounted on the telephone box and, due to side tone considerations, the receiver was separate, on a cable. When the telephone was not in use, the receiver was hung on a spring-loaded hook; its weight would cause the hook to swing down and open an electrical contact, disconnecting the telephone from the line. When the handset is on the cradle, the telephone is said to be "on-hook", or ready for a call. When the handset is off the cradle, the telephone is said to be "off-hook", or unable to receive any (further) calls.