Synopsis Auto Dialler
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Transcript of Synopsis Auto Dialler
Project synopsis
OnAutodialler Security system with voice
message
Submiited to:
Submitted by:
OBJECTIVE
Auto Dialler Circuit
IntroductionIn this project we show that how we use the telephone as a electronics eye.
With the help of landline phone we check and examine the position of the
house automatically. In this logic we attach some sensor with the telephone
and if there is any mis happening then telephone is automatic on and then
circuit press the redial button of the telephone and then telephone dial the
pre-dialied number and sense the voice message to the received end. All
these logic is to be divided into few parts.
ACTION OF STEPS
Sensor unit.
Micro controller interface
Switch on the telephone
Redial the number
Activate the voice processor.
Transfer the message on the telephone line
Switch off the telephone line after sending the message.
SENSOR UNIT.
In this sensor unit it is our choice , how many sensor’s we use , IN this
project we use two sensor’s, In this project we use two electronics circuit
with infra red sensor’s and fire alarm sensor.
In the infra red sensor. We use ic 555 as a main component. Pin no 4 and pin
no 8 is connected to the positive supply. Pin no 1 is connected to the
negative voltage. One capacitor is grounded from the pin no 5 for noise
cancellation. Output is available on the pin no 3. Sensor is connected to the
pin no 2.
In the case of infra red sensor. Pin no 2 is negative bias through the 33k ohm
resistor and pin no is positively biased through the photodiode. One infra red
transmitter l.e.d is focused to the photodiode . Infra red l.e.d is directly
connected to the positive and negative supply through the 470 ohm resistor..
In normal stage when light is focus on the photodiode then pin no 2 is
positively biased photodiode. If pin no 2 is positive then negative output is
available on the pin no 3. Now when any body interrupt the light then there
is no light on the photodiode and pin no 2 is now gets its voltage from only
33 k ohm resistor. If pin no 2 is become negative then output is shifted to
the pin no 3. when positive output is available on the pin no 3 and with the
help of this voltage NPN transistor is on and npn transistor provide a
negative voltage as a pulse to the microcontroller.
If we connect two sensor as a input to the microcontroller then we use same
circuit with the ic 555 .
Note that microcontroller sense only negative input to the microcontroller.
MICROCONTROLLER CONTROL.
ATMEL AT89C2051 Pinout and Description
The 2051 is a low voltage (2.7V - 6V), high performance CMOS 8-bit microcontroller with 2 Kbytes of Flash programmable and erasable read only memory (PEROM). This device is compatible with the industry standard 8051 instruction set and pinout. The 2051 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. The 2051 provides the following features:
~ 2 Kbytes of Flash ~ 128 bytes of RAM ~ 15 I/O lines ~ two16-bit timer/counters ~ five vector, two-level interrupt architecture ~ full duplex serial port ~ precision analog comparator ~ on chip oscillator and clock circuitry
In addition, the 2051 is designed with static logic for operation down
to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.
To learn how to use the 2051 microcontroller, get the Microcontroller Beginner Kit (click here)
2051 - 24MHz DIP Available
The 2051 can be programmed using a device programmer such as the PG302 (Click Here).
We also have Projects that use the 2051 Microcontroller. See the Intermediate Tutorial Section.
This page last updated on April 7, 2003.
All the input sensor is connected to the pin no 18 and 19. Pin no 18 is
connected to the P1.6, and pin no 19 is connected to the P1.7. pin no 20 is
connected to the positive supply. Pin no 1 reset pin. One capacitor is
connected from positive to pin no 1 and one resistor is grounded from pin
no 1. One microswitch is connected across the capacitor fro manual reset
switch.
One buzzer is connected to the pin no 16 ( Port p1.4) this buzzer is on when
circuit sense a input from the input sensor’s. .
Microcontroller sense the input and then we switch on the telephone line
optocoupler. Here we use 817 optocoupler. Once the optocoupler is on one
270 resistor is connected in parallel with the telephone line. After this we
press the flash button of the telephone dialer circuit. For flash purpose we
provide a negative pulse to the flash point for this we CLR P1.1 and after
some delay we SET the P1.1 and after pressing the flash button we press the
redial number. For this we press the pin no 12 ( port p1.0) and after some
delay again we set the P1.0
After pressing the flash button, redial button and switch on the telephone
line we switch on the memory ic. We press the pin no 24 of the isd 1420.
ISD 1420 is a voice processor ic. Output from the voice processor is
available on the pin no 14 and 15 and this output is coupled to the
transformer and output from this transformer is connected to the telephone
line. At the same time telephone dialer ic provide a pulse of the telephone
number to the telephone line.
Telephone dialer circuit.
In this portion of telephone dialer circuit we use the telephone dialer
circuit. For this we use one dtmf generator circuit to generate a dtmf tones
from the circuit. For this purpose we use one DTMF generator circuit to
generate a dtmf tones from the circuit. We connect one telephone keypad or
push to on switches with this circuit. We use total 14 push to on switches
with this circuit to dial the dtmf tones. Once we dial the number in the
dialer circuit. Now when micrcontroller press the redial switch then circuit is
on and redial the pre-dial number .
All the switches are connected to the pin no no 12,13,14,15,16,17,18. All the
switches are connected in row and matrix combination including redial and
flash switch
DTMF LOGIC
In DTMF there are 16 distinct tones. Each tone is the sum of two frequencies: one from a low and one from a high frequency group. There are four different frequencies in each group.
Your phone only uses 12 of the possible 16 tones. If you look at your phone, there are only 4 rows (R1, R2, R3 and R4) and 3 columns (C1, C2 and C3). The rows and columns select frequencies from the low and high frequency group respectively. The exact value of the frequencies are listed in Table 3 below:
TABLE 3: DTMF Row/Column Frequencies
LOW-FREQUENCIES
ROW # FREQUENCY (HZ)
R1: ROW 0 697
R2: ROW 1 770
R3: ROW 2 852
R4: ROW 3 941
HIGH-FREQUENCIES
COL # FREQUENCY (HZ)
C1: COL 0 1209
C2: COL 1 1336
C3: COL 2 1477
C4: COL 3 1633
C4 not used in phones
Thus to decipher what tone frequency is associated with a particular key, look at your phone again. Each key is specified by its row and column locations. For example the "2" key is row 0 (R1) and column 1 (C2). Thus using the above table, "2" has a frequency of 770 + 1336 = 2106 Hz The "9" is row 2 (R3) and column 2 (C3) and has a frequency of 852 + 1477 = 2329 Hz.
The following graph is a captured screen from an oscilloscope. It is a plot of the tone frequency for the "1" key:
You can see that the DTMF generated signal is very distinct and clear. The horizontal axis is in samples. The frequency of the tone is about 1900 Hz - close to the 1906 Hz predicted by Table 3 (697+1209).
CIRCUIT DIAGRAM USE IN THIS PROJECT FOR TELEPHONE
DIALLER IS GIVEN BELOW. In this circuit we use ic 91215 as adtmf
generator. Pin no 15,16,17,18 is a row and pin no 12,13,14 is a row. All the
switches are connected to these pins. Redial button and flash button is
connected to the microcontroller output pin s no 13 and 12 . Output from the
91215 is available on the pin no 7 of the ic . Output from the 91215 is
further amplify by the ic 741. Here pin no 7 of the ic 741 is connected to the
positive supply and pin no 4 is connected to the negative supply. Pin no 6 is
the output pin and amplify signal is available on this pin and again further
amplify by the two transistor circuit. Output from the transistor circuit is
connected to the one coil of the output transformer.
Now when we press a redial number then 91215 generate a pre-dial tones
and this signal is further connected to the coil and further pass on the
telephone line.
Components required:
IC4433
Ic 91214
89c2051
push to on sw
555 timer
.001 µf,0.1 µf,0.01µf
1µf,
220k,470k,4.7k,10k,
crystal 11.0592 MHz
3.38 MHz.
buzzer,
condenser Mic
speaker 8 ohm
relay 12v 100 ohm
transformaer 6v 500mA
infrared Sensor,
heat Sensors
connecting wires
copper clad board
tel line
mic
speaker
BLOCK DIAGRAM AUTO DIALER
SECURITY SYSTEM
STEPS TIME RESPONSIBILTY
PROJECTS
MCU
Speech ICFor voice recording
Auto Dialler Circuit
DTMFencoder
Keyboard
Timer Circuit
Sensor input
SELECTION
CIRCUIT AND
THEORY
ARRANGEMENT
CHECKING
AVAILABILITY
OF
COMPONENTS
TESTING
CIRCUIT
PCB DESIGN
COMPONENT
INSERTION AND
SOLDERING
TESTING
REWORK OR
TROOUBLE
SHOOTING
Uses:Easy to implementReliable,Low cost,Components easily available in market.
Applications:
Home security
Car security
In hospital patient security
Machine monitoring
Bibliography:
www.ludhianaprojects.com/auto dialler.doc