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GSM Based Temperature Monitoring System full report
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[attachment=2598]

GSM Based Temperature Monitoring System

ABSTRACT
In recent years industrial automation and control systems are an integral part of an industry and hence the project temperature monitoring system is an important system in this state of affairs.
TMS aims at monitoring the temperature statistics in a factory, room etc, and controlling peripheral systems. It uses embedded technology from Intel Corporation and built for application in highly sensitive and critical systems.
Through the system we try to bring down the overhead involved in monitoring the temperature statistics in various fields such as factory, air condition areas etc. With the obvious and immediate usage as a system controller it is a complete implementation of dynamic system management.
The system is aimed to meet the following prerequisites:
To sense the temperature
To display the temperature
To display the date and time
To set temperature limits
To control the connected systems
To save the history of limit crossings


resented By Guided by
Sujadevi.S. Mr. Asni.H.
DeepuDevaraj Mrs. Sumol
Elby Basil

Advantages
In a dynamic scenario wherein the breed and nature of real time systems are subjected to promising changes TMS is aimed at adding the fundamental functionality of interfacing them with varying ambience enabling them to be stable and reliable.
BLOCK DIAGRAM:
Temperature Transducer 1
2 Channel
ADC
*
Display
t
M Cont cro roller
Level w GSM
Translator Module
Temperature Transducer 2
DC Power Supply
AC Source
CIRCUIT DIAGRAM:
ycc
PI 0/T2 PO.O/ADO
P1.1/T2-EX PO 1/AD1
P1 2 P0.2/AD2
PI.3 PO 3/AD3
PI 4/SS P0.4/AD4
P1.S/MOSI P0.5/AD5
PI 6/M1SO P0.6/AD6
PI 7/SCK PO 11 AD 7
P2 0/A8
P3 7/RD P2 1/A9
P2 2/A10
P3 6/WR P2 3/A11
P3 5/T1 P2 4/A12
P3 4/TO P2.5/A13
P3 3/iHJJ P2 6/A14
P3 2/INTO P2.7/A15

RST ALg/PROG
EA/VPP
XTAL2 P3 0/RXD
P3 1/TXD
XTAL1 Z
BLOCK DIAGRAM DESCRIPTION SIGNAL CONITIONING CIRCUIT: -
Signal conditioning circuit consists of two temperature transducers and an Analog to Digital Converter. The transducer converts the temperature to proportional electrical signal. The Temperature sensor used here is LM35 which has a resolution of
1 Celsius.
ANALOG TO DIGITAL CONVERTER:
An 8 Channel ADC is used since there is more than one sensor output that should be converted into digital format before feeding to the Micro Controller.
INTERFACING OF GSM UNIT: -
Interfacing of GSM unit through a serial communication page link with microcontroller 89S51. Whatever data is to be sent to GSM unit is done through this RS 232 link.
LEVEL TRASLATOR: -
Level translator Translates TTL voltage level to RS-232 compatible level. It is realized with MAX 232.
SIGNAL CONDITIONING CIRCUIT:
Signal conditioning is widely used in the word of data acquisition. Signal conditioning circuit have two parts- two temperature transducers and an analog to digital converter.
Transducer Section (Temperature Sensor) LM 35:
+VS g VOUT
VCC LM35D
1 A
Transducers convert physical data such as temperature, light intensity, flow and speed to electrical signals. Depending on the transducer the output produced is in the form of voltage, current, resistance or capacitance.
The temperature transducers convert temperature into electrical parameters, e.g.: thermistor, thermocouple. A thermistor responds to temperature change by changing resistance but its response is not linear. Simple and widely used temperature sensors include the LM 34 and LM 35 series.
The LM 35 series sensors are 3 pin precision integrated circuit temperatures whose output voltage is linearly proportional to the Celsius (centigrade) temperature. The LM35 thus has an advantage over linear temperature sensors calibrated in 0 Kelvin, as the user is not required to subtract a large constant voltage from its output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of 1/4 C at room temperature and 3/4 C over a full -55 to +150 C temperature range. It can be used with single power supplies, or with plus and minus supplies. As it draws only 60 uA from its supply, it has very low self-heating, less than 0.1 C in still air.
Features:
> Calibrated directly in Celsius (Centigrade)
> Linear + 10.0 mV/ C scale factor
> Rated for full -55 to +150 C range
> Suitable for remote applications
> Operates from 4 to 30 volts
> Less than 60 uA current drain
Analog to Digital Converter 0808:
vcc
+VS VOUT
GND LM35D
+VS VOUT
GND LM35D
Analog to digital converters are among the most widely used devices for data acquisition. Microcontrollers use binary (discrete) values, but in the physical world everything is analog (continuous). Here the output of LM 35 is an analog signal in the form of voltage. Therefore, we need an analog to digital converter to translate the analog voltage to digital form so that the microcontroller can read and process them.
An 8 Channel ADC is used since there is more than one sensor output that should be converted into digital format before feeding to the Micro Controller.
Both the sensor outputs are fed to the two different channels of ADC 0808.The channels are selected using the select pins which are controlled according to the signals from micro controller.
The ADC0808 is a monolithic CMOS device with an 8-bit Analog-to-Digital converter, 8-channel multiplexer and microprocessor compatible control logic. The 8-bit A/D converter uses successive approximation as the conversion technique. The converter features a high impedance chopper stabilized comparator, a 256R voltage divider with analog switch tree and a successive approximation register. . The 8-channel multiplexer can directly access any of 8-single-ended analog signals. The device eliminates the need for external zero and full scale adjustments. Easy interfacing to microprocessors is provided by the latched and decoded multiplexer address inputs. The ADC0808 offers high speed, high accuracy, minimal temperature dependence, excellent long-term accuracy and repeatability, and consumes minimal power. These features make this device ideally suited to applications from process and machine control to consumer and automotive applications.
In ADC 0808. Vref (+) and Vref (-) set the reference voltage. If Vref (-) = GND and Vref-(+) = 5V, the step size is 5v/256 = 19.53mv. Therefore to set a lOmv step size we need to set Vref (+) = 2.56v and Vref (-) = GND. SC is for Start Conversion. SC is the same as the WR pins in other chips. EOC is for End Of Conversion and OE is for Output Enable (READ). The EOC and OE are the same as INTR and RD pins respectively.
The ADC 0808 has no self clocking. So the clock must be provided from an external source to the CLK pin. Although the speed of conversion depends on the frequency of the clock connected to the CLK pin, it cannot be faster than lOOmicrosecs.
Timing diagram
3C
0U1PJT t<lH.( '
'iOC
f
<
>
Features:
> Easy interface to all microprocessors
> 8-channel multiplexer with address logic
> OV to 5V input range with single 5V power supply
> Outputs meet TTL voltage level specifications
> Resolution 8 Bits
> Single Supply 5 VDC
> Conversion Time 100 ms
CLOCK GENERATOR:
An astable multivibrator using IC 555 is used here for providing the clock signals. The frequency of the clock signal is 500Hz. NE 555 is a timer IC configured as the frequency running oscillator provides the clock for ADC. It is basically switching circuit that has two distinct output levels. As a result the circuit continuously switches back and forth between two unstable states. In other words, circuit oscillates and output is a periodic rectangular waveform. Since neither output
V +5V
O/P CLK
state is stable, then circuit is said to be astable and is often referred to as free running or astable multivibrator.
In the circuit, the capacitor, the timing capacitor is charged towards +Vcc through Rl and R2. The charging time Tl is given as
T1=0.693(R1+R2)C1.
This is the time during which output is high. The timing capacitor CI is then discharged towards GND through the resistor R2. The discharge time T2 is gives as
T2=0.693R2.C1
This is the time during which the time is low. The period T of the oscillating clock is the sum of Tl and T2. Thus
T= Tl+T2= 0.693(R1+2R2).C1
The frequency oscillation is then found as
F=1/T=1.44/(R1+2R2)C
MICROCONTROLLER 89S51:
The AT89S51 is a low-power, high-performance CMOS 8-bit microcontroller with 4K bytes of downloadable Flash programmable and erasable read-only memory. The on-chip downloadable Flash allows the program memory to be reprogrammed In-System through an SPI serial interface or by a conventional non-volatile memory programmer. The AT89S51 provides the following standard features: 4K bytes of downloadable Flash. 128 bytes of RAM, 32 I/O lines, programmable watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port. In addition, the AT89S51 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 external interrupt or hardware reset.
Features:
> 4K Bytes of In-System Reprogrammable Downloadable Flash Memory
> 4V to 6V Operating Range
> Fully Static Operation: 0 Hz to 24 MHz
> 128 x 8-bit Internal RAM
> 32 Programmable I/O Lines
> Three 16-bit Timer/Counters
> SPI Serial Interface
AT 89S51 Serial Programming
The microcontroller AT 89S51 can be programmed in both serial mode and parallel mode. The Serial programming was carried out as it does not required extra burning module. The serial programming of AT 89S51 is done using the personal computer, through the printer port. The AT89S51 in its serial mode programming mode is shown in the figure.
P
AD DR. QOOB'FFH
SEE FLASH PRCGRA'vlMINCH MODES TABLE
3-33 MHz
PGM DATA
PROG
RDY/ BSY
The microcontroller AT 89S51 is serially programmed using the software ATMEL ISP Flash Programmer Version 3.0 through the printer port of the computer.
Serial Programming Algorithm
To program and verify the AT89S52 in the serial programming mode, the following sequence is recommended:
1. Power-up sequence: Apply power between VCC and GND pins. Set RST pin to "H". If a crystal is not connected across pins XTAL1 and XTAL2, apply a 3 MHz to 33 MHz clock to XTAL1 pin and wait for at least 10 milliseconds.
2. Enable serial programming by sending the Programming Enable serial instruction to pin MOSI/P1.5. The frequency of the shift clock supplied at pin SCK/P1.7 needs to be less than the CPU clock at XTAL1 divided by 16.
3. The Code array is programmed one byte at a time by supplying the address and data together with the appropriate Write instruction. The write cycle is self timed and typically takes less than 1 ms at 5V.
4. Any memory location can be verified by using the Read instruction which returns the content at the selected address at serial output MISO/P1.6.
5. At the end of a programming session, RST can be set low to commence normal device operation.
The connection diagram with the pins of the serial port for serial programming of AT 89S51 is as shown in the figure below
2;ad: J S/AIC
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O . K
P3SRKC ' ii 1 0
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msa nans
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I*
*S1
VCC
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V
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LIQUID CRYSTAL DISPLAY:
Liquid state have been called the fourth state of matter(after solids, liquids and gases) because they have certain crystal properties normally found in solids, yet flow like liquids. Unlike LEDs and other electronic devices, LCDs do not generate light energy, but simply alter or control existing light to make selected areas appear bright or dark.
There are two fundamental ways in which liquid crystal are used to control properties of light and therefore after its appearance. In the dynamic scattering method, the molecules of the liquid crystal acquire a random orientation by virtue of an extremely applied electric potential. As a result light passing through the material is reflected in many different directions and has a bright frosty appearance as it emerges.

In the absorption method the molecules are oriented in such a way that then after the polarization of light passing through the material. Polarizing filters are used 2 absorb or pass the light depending on the polarization it has given, so light is visible only in those regions where it cam emerge from the filter.
In recent years, LCD is finding wide spread use of replacing LEDs. This is due to the following reasons:
1. The declining prices of LCDs.
2. The ability to display numbers, characteristics and graphics. This is in contrast to LEDs which are limited to numbers and a few characteristics.
3. In corporation of a refreshing controller into the LCD, thereafter relieving the CPU of the task of refreshing the LCD. In contrast, the LED must be refreshed by the CPU to keep displaying the date.
4. Ease of programming for characteristics and graphics.
The connection of LCD with microprocessor is shown in the figure.
The 8-bit data pins, D0-D7, are used to send information to the LCD or read the contents of the LCDs internal registers. To display letters and numbers, we send ASCII codes for the letters A-Z, a-z and numbers 0-9 to these pins while making RS=1( to select data registers).
There are also instruction command codes that can be sent to the LCD to clear the display or force the cursor to the home position or blink the cursor.
We also use RS=l(to select command register) to check the flag bit if the LCD is ready to receive information. The flag is D7 and can be read when R/W=l and RS=0. When D7=l (flag=l), the LCD is taking care of internal operation and will not accept any new information. When D7=0, the LCD is ready to receive new information.
RS 232 INTERFACE:
5 V
16
'CC
0 V
JT
C3t ^ 1 uF
..:.. + 85 v
- -3.5 V
C4'X^ 1 uF
EIA-232 Output EIA-232 Output EIA-232 input EIA-232 Input
I 15 GND
Serial port is harder to interface than parallel port. In most cases, any device you connect to serial port will need the serial transmission converted back to parallel so that it can be used. This can be done using a UART. On the software side of things, there are many more registers that you have to attend then on a standard parallel port (SPP). Serial cables can be longer than parallel cables. They also do not need as many wires as parallel transmission.
RS 232 stands for Recommended Standard 232. RS 232 is the most widely used serial I/O interfacing standard. This standard is used in PCs and numerous types of equipment.
In RS 232, a l is represented by -3 to -25V while a 0 is represented by +3 to +25V,making -3 to +3 undefined where as a serial port transmits a 0 as 0V and l as 5V. This standard was set long before the advent of the TTL family, its input and output voltage levels are not TTL compatible. For this reason to connect any RS 232 to a microcontroller system we must use voltage converts such as MAX 232 to convert the TTL logic levels to the RS 232 levels and vice versa.
MAX 232:
The 8051 has two pins that are used specifically for transferring and receiving data serially. These two pins are TxD and RxD which are TTL compatible. Therefore this requires a line driver to make their RS 232 compatible. One such line driver is the MAX 232 chip from maximum co-orperation.the MAX 232 converts from RS 232 voltage levels to TTL voltage levels and vice versa. One advantage of the MAX 232 chip is that it uses a +5V power source which is the same source voltage for the 8051. In other words with a single +5v power supplies we can power both 8051 and MAX 232, with no need for the dual power supplies that are common in many older systems.
The MAX 232 has two sets of line drivers for transferring and receiving data. The line drivers used for TxD are called Tl and T2 which the line drivers for RxD are designated as Rland R2. In many applications only one of each is used. Here also used only one set of transmitter and receiver Tl and Rl.MAX 232 requires four capacitors ranging from 1 to 22microF.the most widely used value for these capacitors is 22microF.
GSM EQUIPMENT: Introduction to GSM:
GSM (Global System for Mobile Communications) is world's most famous Mobile platform. Mobile phones with SIM cards use GSM technology to help you communicate with your family, friends and business associates.
GSM systems have following advantages over basic land line telephony systems:
1. Mobility
2. Easy availability
3. High uptime
We use communication feature of Telephone landlines for internet, e-mail, data connectivity, remote monitoring, computer to computer communication, security systems. In the same way we can use GSM technology and benefit from its advantages.
Uses GSM technology for following applications:
1. Access control devices: Access control devices can communicate with servers and security staff through SMS messaging. Complete log of transaction is available at the head-office Server instantly without any wiring involved and device can instantly alert security personnel on their mobile phone in case of any problem.
2. Transaction terminals: EDC (Electronic Data Capturing) machines can use SMS messaging to confirm transactions from central servers. The main benefit is that central server can be anywhere in the world.
3. Supply Chain Management: With a central server in your head office with GSM capability, you can receive instant transaction data from all your branch offices, warehouses and business associates with nil downtime and low cost.
GSM UNIT:
The GSM Modem supports popular "AT" command set so that users can develop applications quickly. The product has SIM card holder to which activated SIM card is inserted for normal use. The power to this unit can be given from UPS to provide uninterrupted operation. This product provides great feasibility for devices in remote location to stay connected which otherwise would not have been possible where telephone line do not exist.
"AT" COMMANDS:
AT commands, also called Hayes AT commands, are based on the Hayes Modem de facto standard, ATTENTION Commands for modems. They are used to communicate with your modem. These commands modify your modem's behaviour or instruct the modem to do something specific, such as dialling a telephone number. The "AT" refers to getting the Attention of your modem.
To send a command to modem, we need to start a terminal program such as Windows Hyper Terminal .No matter which terminal program you use, it should be configured to communicate with the COM port that your modem is attached to. You then type commands in the Terminal window. The modem executes the command and responds appropriately. One set of AT commands will identify your modem and version information.
Eg: -ATD [<dial_string>][;]
Dials the phone number specified in the <dial string>parameter.
INTERFACING OF GSM UNIT:
Interfacing of GSM modem is done through a serial communication page link between the modem and microcontroller 89S51. Whatever data is to be sent to GSM modem is done through this RS 232 link. The different initialising signals and commands are sent as data packets.
APPLICATIONS OF GSM MODULE:
1. Remote Condition Monitoring:
Wire free telemetry allows the early identification of a problem and can save expensive down time and repair costs. Automated data collection means the information is available at any time, any place, saving costly visits to site. In a typical remote industrial monitoring application, when perhaps a cellular solution is being used to check the status of a machine using GSM, then the use of a wireless monitor comes into its own.
2. Data Capture for Remote People Counting:
Remote monitoring techniques used in conjunction with suitable sensors are used capture data and count people in retail outlets. By knowing how many people have entered or left each establishment then the effectiveness of sales and marketing campaigns can be monitored. When used in conjunction with RFID then the movement of staff can be monitored which is particularly appropriate in areas where there are a lot of staff and relatively few customers. By monitoring footfall remotely the data can be viewed centrally, so you could look at many stores across regions to compare effectiveness geographically.
3. Wire Free Security Alarms:
Wire free security alarms using cable free motion detectors and GSM capable communication devices for sending text messages are well suited to building sites, temporary offices. The lack of cable means that the can be installed very quickly, location of sensors can be quickly altered to suit the changing needs of the building and alarms can be quickly and easily configured to be sent to mobile phones. The remote alarm system can also works without mains power.
POWER SUPPLY SECTION:
D1 4- ^
U1
IN OUT Q
C1
C2
T2
C78L05
V1
D3
f
The power section consists of a transformer, bridge rectifier and voltage regulator. This project uses a transformer of 230V ac primary to 0-9V, 1A secondary. A transformer isolates dc supply from ac main. The bridge rectifier converts AC signal into DC and is filtered using capacitor filter. Its output voltage changes when load current or line voltage varies. An electronic circuit which keeps the output voltage constant irrespective of the variation in the load current, line voltage and temperature is an electronic voltage regulator. This is added at the output of the unregulated power supply.
The voltage regulator is a circuit that provides a precision output voltage under varying load condition and possibly varying input voltage. Here we need a +5V so that the output of the filter is fed to LM 7805, a voltage regulator which gives an output voltage of +5v dc.
Voltage Regulator LM7805C:
The LM78XXC monolithic 3-terminal positive voltage regulators employ internal Current-limiting, thermal shutdown and safe-area compensation, making them essentially indestructible. If adequate heat sinking is provided, they can deliver over 1 .OA output current. They are intended as fixed voltage regulators in a wide range of applications including on-card regulation for elimination of noise and distribution problems associated with single-point regulation. In addition to use as fixed voltage regulators, these devices can be used with external components to obtain adjustable output voltages and currents.
Block diagram:
INPUT
lO
SERES
pass
EIEMEN1
OUTPUT
OZ
STARTING CIRCIKT
CUR G ME( }ENT SATOft

REFERENCE VOUACE
SOA PROTECTION
ERROR AMPUFEfi
THERMAL PROTECTION
GNO -03
O
Application Circuit:
L78XX 2 ^


mil i/i j
a33/uF 3 Co:
OJ/uF
5 -2703/ 2
Features:
> Complete specifications at 1A load
> Line regulation of 0.01 % at 1A load
> Load regulation of 0.3%
> Internal thermal overload protection
> Internal short-circuit current limit
SOFTWARE
IDE- KEIL uVision:
The software for GSM based temperature monitoring system is written in Assembly language of 8051. The program is assembled using KEIL pVision assembler which is available in the internet. pVision, from Keil Software, combines Project Management, Source Code Editing, Program Debugging, and Flash Programming in a single, powerful environment.
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Eh &t Sofia Qffaucj
ii s y- & w <
& .11 > W Ci>
. IP a fe-
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m 0*00000000
Rl 0*C000031B j
R2 0-O0OOC318
R3 0*00000001 j
R4 0*00000560 1
R5 0x00000204 !
R6 OxHfcOOCO i
R7 OxIllcQOCO j
R8 0x01001154 1
R9 0x00000010
RIO 0x0000004c 1
R11 0x00001134 .
R12 0xCO001e54 1
R13 SP 0x00001104 1
R141LRI Oxoiooae :
R15IPCI GxOlOOabc !
* CPSR 0x60000010
* SPSR 0x60000010 1
>:' >
- F s> Interne*
R8 0*00000000
R9 oxcoxmn i
RIO OxOO 1
R11 OxOO
R12 0x00000000
R13JSPJ oxooi ire
R14ILRI OxOO
* SPSR OxOO
Inlenupt
Supeivisw
Abo.'
Undetw)
117224943
295669019
Infernal PC t Mode Stales
2 U\1u * *
PRESCAL: 0x09 Com-Tine 5 500u
Q SLEEP P] RES G TRGEN
AOC0.CR OxOOQOO
1JCH2 bjem bCHO
AOCO.MR' 0x00000910 TRGSEL: TIOAO *
Lham<ef'S;eiu$ ADCO.CHSR OkOOKIOOF
A0COJMR CWXOXBOO
OVRFCM1EnvPF1 OVREO EOC3EOC2EOC1 EOCO
D G
ADO: 0 2O0O
AOVREF: 3 0000
:.r.L1 ni pTk^I ^^feOJ234g pwiE 0x0FF448l analog-0x023j
AD1: *<00O AD2 1 2000 A03: 06600
Execution peicentage OX oi 31 r
Cutent Module Me*tu : Module i/Finctiom
R3 ,#0*0000.0 QxQ10QQAB4
R3.#0x00000001 R3.[R5]
:urrent MeasurBments: (ESC to abort)
00:03.547 PA:01234567 PB:0FF74489 AO:0.2OV A1:2.4GV A2:1.20V A3:0.6
Adie .
B_iecoKj
AnalogO (3.000000) ent r d.
ASSIGN BreakDisable BreakEnable BreakF.ill t<
W*F2to
stmct clock ( : OnOI 234567 : Cb4TFF4488 : 0xfl0000570(
0xO0CO05A0: OO00O0FF 00000000 00000000
OxO0OO05AC: 00000000 00000000 OOFF
!OxO0DO05B8: 00000000 00000000 00000000
000005C4: 00000000 OOFF 00000000
nn nn
"Q !CuV""i- rii-.r.nr-inn nnfifi winn^nfi
l-jl.Hi\Mefnorv#i j\ Mernory^ A Mtmory #3 /, Mem
fig. Screenshot of KEIL micro vision
FLOW CHART:
START
INITIALISE ALL PORTS TO FFH
DISABLE ALL INTERRUPTS
INITIALISE THE DISPLAY
INITIALISE UART WITH BAUDRATE 9600

1
READ DATA FROM ADC
DISPLAY PRESENT TEMP AND LIMIT
ALGORITHM:
Stepl: Initialise all Ports to FFH Step2: Disable all interrupts.
Step3: Initialise LCD and UART with Baud Rate 9600 Step4: Read the output of ADC from both the channels Step5: Display the present temperature and limit Step6: Compare present temperature with the limit set.
Step7: If limit is crossed, send the formatted information to the GSM unit through serial communication page link else go back & read the ADC outputs.
ARTWORK:
CONCLUSION:
GSM Based Temperature Monitoring System was a project based on microcontroller, due to which hardware requirement is reduced. Modifying the software will be enough for further enhancement of our project. In a dynamic scenario wherein the breed and nature of real time systems are subjected to promising changes, this project is aimed adding the fundamental functionality of interfacing them with varying ambience enabling them to be stable and reliable.
By doing this project, we were better able to understand the various facets of doing an embedded system project which is emerging as one of the most 'in demand' technologies right now. Eventhough this project was developed to alert in crucial circumstances, this can be expanded for controlling the temperature also.
The development of this project has shown how much hard work goes into the creation of a system. Embarking of this project has helped us in developing a team spirit, patience and time management necessary for today's technical professionals. This project has built in us confidence that any problem can be solved with sheer determination, hard work and optimism.
APPENDIX
APPENDIX - A
SOURCE CODE:
/* PORT ASSFNGMENT:-
P0->LCD DATA LINES P1->ADC DATA P3.4->SELECT LINE A P3.5->SELECT LINE B P3.6->SELECT LINE C P2.5->LCD RS P2.6->LCD E P2.7->LCD R/W */
ORG 0000H AJMP 0020H; ORG 0020H
MAINE
LOC:
MOV P1.#0FFH; ACALL DISPINIT; MOV A,#80H; ACALL CWRT; ACALL DORG; MOV A,#0C0H ACALL CWRT; ACALL DORG1; ACALL ADCREAD; MOV R5,#0FFH; ACALL DELAY; MOV R5,#0FFH; ACALL DELAY; MOV R5.#0FFH; ACALL DELAY; JMP MAIN1 ;
PORT 1 AS I/P
FIRST LINE OF LCD
INITIALIZING ;SECOND LINE OF LCD
CLR A;
MOV DPTR,#8F8H; ACALL DSEND; MOV R5,#02H;
LOADING; CALL DELAY;
CLR A;
MOV DPTR,#911H; ACALL DSEND; RET;
LOAD GSM TEMP
I* ** DISPLAY INITIALISATION* * **/
DISPINIT:
MOV A,#38H; ACALL CWRT; MOV A,#14H;
ACALL CWRT; MOV A,#0CH;
ACALL CWRT; MOV A,#01H; ACALL CWRT; RET;
LCD 5*7&2LINES
DISPLAY ON CURSER NOT BLINK
DISPLAY ON CURSER NOT BLINK
DISPLAY CLEAR
MOV P0,A; CLR P2.5; SETB P2.6; ACALL SDELAY; CLR P2.6; ACALL SDELAY; SETB P2.6; RET;
RS->0 E->1
E->0
E->1
/**Q^'T'^ WRITE TO LCD**/ DWRT:
MOV P0,A;
SETB P2.5; RS->1
SETBP2.6; E->1
ACALL SDELAY;
CLR P2.6; E->0
ACALL SDELAY;.
SETB P2.6; E->1
ACALL SDELAY;
RET;
SHORT DELAY**/
SDELAY:
MOV R3,#10H;
LOCI: DJNZ R3,LOCl;
RET;
/**L)ATA SEND TO LCD**/ DSEND:
CLR A;
ACALL SDELAY; MOVC A,@A+DPTR; CJNE A,#00H,LOC4; RET;
LOC4:
ACALL DWRT; INC DPTR; SJMP DSEND;
DELAY: MOV R4, #0FFH;
HERE: DJNZ R4, HERE;
DJNZ R5, DELAY;
RET;
ADCREAD:
MOV P1,#0FFH; PORT 1 AS I/P
CLR P3.4;
CLRP3.5; ADD SELECT
CLR P3.6;
CLR P3.7;ALE
ACALL SDELAY;
SETB P3.7;
ACALL SDELAY;
CLR P3.7;
MOV R5,#010H;
CALL DELAY;
MOV A,P 1; READING ADC
ANL A,#1FH;
MOV R7.A;
SETB P3.5;
CLR P3.7;ALE
ACALL SDELAY;
SETB P3.7:
ACALL SDELAY;
CLRP3.7;
MOV R5,#010H;
CALL DELAY;
MOV A,P1;
ANL A,#1FH;
ADD A,R7
RRC A;
MOV R6.#030H; JC FIVE;
CARRY: MOV R7,A;
CLRC
SUBB A,#018H; JNC ALARM; MOV A.R7; ACALL CONVE; MOV A,R0; ACALL DWRT; MOV A,R1; ACALL DWRT; MOV A.R2; ACALL DWRT; MOV A,#02EH; ACALL DWRT;
MOV A,R6; ADDING DECIMAL POINT &
DISPLAY
ACALL DWRT;
LOC3: RET;
^**SI:**H<**I_JC7^ TO f3CD (CONVERSION**/
CONVE:
MOV R(),#30H; MOV R1,#30H; MOV R2,#30H MOV B,#02H; MUL AB; MOV B,#64H
LOC2:
DIV AB; ADD AR0 MOV RO.A; MOV A,B; JZ LOC2; MOV B.#0AH; DIV AB; ADD A.Rl; MOV Rl.A; MOV A,B JZ LOC2; ADD A,R2; MOV R2,A; RET;
ALARM* * **
**/
ALARM:
MOV A,#01H; ACALL CWRT; MOV R5,#02H; ACALL DELAY; MOV A,#80H; ACALL CWRT; MOV R5,#02H; ACALL DELAY; CLR A;
MOV DPTR,#91BH; ACALL DSEND; CALL SERIALROUTINE; JMP LOC3;
CALL DELAY;
CALL DELAY;
y** * *S RiALROUTINE* * **/
SERIALROUTINE:
UARTINIT:
MOV TMOD,#020H;#10H
MOV TH1,#0FDH MOV SCON,#050H;#10H SETB TR1 CLRTF1
MOV PCON,#070H
TIMER1 IN MODE [(ADC)JIMERO IN MODE 2(RS232) BAUD RATE SET SERIAL MODE
RUN TIMERO
**!(:*
;TX_CHAR TRANSMIT ONE CHAR. THRO' SERIAL INTERFACE ;INPUT CHAR. TO BE TRANSMITTED IN ACC.
TX CHAR:
TRANS 1:
SKIP:
HERE2:
MOV DPTR,#800H
MOV R5,#010H ACALL DELAY CLR A
MOVC A,@A+DPTR; CINE A,#00H,SKIP JMP OVE;
INC DPTR; MOV SBUF, A
JNB Tl, HERE2 CLR Tl
SKIPTX: OVE:
JMP TRANS 1; RET:
/
DATA TO BE DISPLAYED**
ORG 800H
ORG 900H
END
DB "ATD9995238051;" DB ODH: DB 00H
DB " INITIALIZING " DB 00H;
DB "GSM TEMP:"; DB 00H;
DB " ALARM!!"; DB 00H;
(9
N a 11 o a a I S e m i c o n d u c t o r
December 19S4
LM35/LM35A/LM35C/LM35CA/LM35D Precision Centigrade Temperature Sensors
General Description
THE LM-JS series aio ptecWtan I ntogratod-ctcuit tempera ture sensors, whoso output voltage is Hn early pro cot Her alto tho Celsius (Centigrade) temperature. THE LWLis thus has an advantage over linear temperature sensors calibrated m" Kelvin, as the uses is rat teqiked to subtract a la<go ooiv slant voltage from its output to obtain convenient Centi grade scaling. The LM3S doos rot iegutre any external cali bration or trimming to provide typical accuracies of i V/'C at toom temperature ana ' %"C ov a lull tb to -150*C tomporature range. Low cost Is assuroa by trimming arc calibration at the wafer level. The LM3b's tow output imped ance, linear output, and precise inherent calibration make interfacing to readout or control errantry especially easy. It can be used with single power supplies, or with plus ana minus supplies. As it draws only 60 tiA from its supply, it HAS very tow self-heating, less than 0.1"C in sUI a'sr. The LM3b is rated to operate over a SS" to - 1S0"C temperature range, white the LM3bC is rated for a - 4TY to - 119*0 range { 10" with unproved accuracy). THO LM35 series is available packaged m hermetic TO-46 transistor packages, while the LM3bC, UvtSbCA. and LMSbD are- also available m the plastic TO-92 transistor package. The LM36D also available m an 8-lead surface mount small outline package and a plastic TO-202 package.
Features
Calibrate ! .aoctfy in " Celsius (Centigrade)
Linear - i\S mV/"C scale factor
05"C accuracy guarantecaole (at - 2b"C>
Rated (oi full bb" to - lbO"C range
Suitable for remote applications
Low cost due to wafot-level trimming
Operates from 4 to 30 volts
Less than 90 i A aw rent drain
Low self-lieatmg, 0.06*C IB still air
Nonlineanty only x Vi"C typical
Low importance output, 0.1 SI fen 1 mA load
Connection Diagrams
TO-46 Metal Can Package*
TO-92 Plastic Package
SO-8
Small Outline Molded Package
j +'s Win SMD \
u j
n.c.
ONC
"S II c.
CI
lime is c<tfTi ':4w:i lu ntxjiilvy i
Order Number LM3SH. LM 36AH. LM3bCH. LM36CAH or LM36DH See NS Package Number H03H
TO-202 Plastic Package
Order Number LM35CZ. LM36CAZ or LM3bDZ See NS Package Number ZD3A
Typical Applications
-Us 14* TO mi
_L
i-.'-niio 2i
Top View
HC l*> Ois'rie<tfeet
Order Number LM36DM See NS Package Number M08A
i 35
T
t outwit
' 0 arV * ICO n V> G
17
m <
I -1il I* 3
FIGURE 1. Basic Centigrade
Temperature Sensori ;-2"C to - 1bO"C)
TUM 5t -i -Vs.' uA
It'lli^l'.i 2A
Order Number LM36DP See NS Package Number PD3A
-i253 mV 4 J5-C
- - 50 tivai -sre FIGURE 2. Full-Range Centigrade Temperature Sensor
Absolute Maximum Ratings (Note 10}
tl Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Olfice/Distributors lor availability and specifications.
Supply Voltage - 36V to -0.2V
Output Voltage - 6V to - 1.0V
Output Cut rent 10 mA
Storage Temp.. TO-46 Package, 60"C to 18CTC
TO-92 Package. WCto - 1S<TC
SO-B Package, 6S"Cto i 1 !>CTC
TO -202 Paskage, - 66"C to + 1 S'CfC
Lcaa Temp.:
TO- 6 Package. (Soldering. 10 seconds) 300"C
TO-92 Package, (SotdennR. 10 socoias) 26CTC
TO-202 Package. (Soldering. 10 seconds) - 23 OC
Electrical Characteristics lNotcD(Note6)
21S"C 220*0 2600V
SO Package (Note 12): Vapoi Phase (60 seconds) Inlrarea (is seconds)
ESD Susceptibility- (Note 11!
Spooled Operating Temperature Range: T,lt!H to TMAX (Note 2)
LM3S, LMS6A 55"Cto ; 1KTC
LM 3SC. LM3BCA - 40"C to + 110>'C
LM360 0"Cto > 100"C
LM3bCA
Parameter
Conditions
Typical
Tested Limit (Note A)
Design Limit (Note bl
Typical
Tested Limit (Note +)
Design Limit (Note bi
Units (Max.)
Accuracy (Note 1)
TA- ! Zb'i
Ta- rye
'0.2
- 0.3
- 0.4
- 0.4
t-0.b
11.0 v 1.0 I 0.2
.!. 0.3
I: 0.4 > 0.'.
.tO.Jt 1.0
1.0 1.5
Morlirvea'% (Mote B)
T,
Ta '.Ti
0.10
0.3 5
0.15
Sorvsor Gam (Avciago Slope)
TI T.
9.9, 10,1
10.0
i 9.9, 10.1 mV/'-C
Load Regulation (Note 3) 0 I;/ 1 MA
TA- 2 &^ TU iSTA TYAX
0.5
3.0
I: 0.*$
0.5
1.0
3,0
mV/mA
LIRE Regulator (Note D) ta- 2re
4V1 V'si 30V
. 0.01 0.02 iO.O
0.1
:' 0.01 0.02
0.1
mV/V mV,.* V
Owe scent Current (Note S)
V5 - - SV. - 2S*C Vs " - bV V's . - 30V. - 2S-C Vs ^ " 30V
105
56.2 105.5
6
66
131
133
91
ye.2
91.5
67 -!>
1 14 116
(JtA I* A M,A
Clvangoof Quiescent Current (Note 3)
lV.-iVss.30V. 25 ' V--;Vss30V
02 0.5
2.0
v'.<:
0.5
Te mporaturo Coefficient of Ouiescert Currorl
Mini rn iirn T err per atuto lo> Rated Accuracy
In 2tJ'l of figure lf*0
1.5
Loi^g Term Stability
Tj -TMAX. 'or 1000 hours
3.01'
0.0b
MAI* 1:UM* t rtiile ea.l^ 6Sl*-fe to!* *oy -55"C ',Tj'. ' ISCPCNSr tie LW3S W LV05A. - *.;Tj< ' 110*CtW W LM 5C *tU SCA, i<f
0'-.Tj'. 10Q'C tar tfxs Vs ^ ifld iiCAD"-* t' r trmrt of r^art* ^. Tr'<**i *i4aK-id!a*s atsu j*sery lnw * 2*C te TJA^c in flur u-jut -:l
Kt/utu i 3pei:1'Oiittfis *i btrfdfaor a:>5% tv * I* fur rafc*J tetfncw*ahj* rir-^j
Noi* Th<*-rnal re*su.ioe ell.':*.* T04fc eaciw^eia 420*C/W. junction fc sn&fcnt and 24* rw ymctionlG case Thermal re**iarteet TO 32 paoka :* 1 QO'CW pjictor te art*s*;nt Therms aslant* &f f* *rjaii outline iTK><Je f a^* is ^C'C/W sun fw te arrive The^r^ii fesst^c-ii ef tiis TO 2Q2 paA^i
Typical Applications ccoo*
0.1 f
mam.
IN* (
I 1
m
y m ' Ktt = 18 i V/*C fteffljm i C)l r I FHSm -S'C K - wrc
i Russia >
FIGURE 7.Ternperature Sensor, Single Supply, 66" TO tbO'C
TUHfllM
FIGURE 8. Two-Wire Remote Temperature Sensor (Output Referred to Ground)
, as
OffKT *D0UST ,
ttffWSSI
FIGURE 9. 4-TO-2t>mA Current Source (0"C LO - 100"C!
FIGURE 11. Centigrade Thermometer (Analog Metcrl
" TUM/5SW 12
FIGURE 12. Expanded Scale Thermometer (bO" to 80" Fahrenheit, tor Example Shown)
FIGURE 13. Temperature To Digital Converter (Serial Output) (I 128"C Full Scale)
FIGURE \ 4. Temperature To Digital Converter (Parallel TRI-STATE* Outputs (or Standard Data Busto uP Interface) (12B"C Full Scale)
(9
Ar alio n a I Se m i c o n d u c t o r
October 1995
ADC0808/ADC0809
8-Bit JJP Compatible A/D Converters with 8-Channel Multiplexer
General Description
"he ACCS806. ADCC-J03 data acquisition conrporetrc is a monolithic CMOS c'ev'ce with ar -3-bt anaiog-to-dtgita con verter. 8-channel nwUo.exef ana microprocessor compatible control log c. The 8-bit NO converter uses successive ap proximator as the conversion technique. Trie convener fea tures a high mpedance chopper stapilzed comparator, a 256R voltage divider with anaog switch tree ano a succes sive approximation register The -channel multiplexer can directly access any of 3-s-ngle-ended anaog signals. he fi-evce eliminates the need for external zero and fU:l-scale adjustments. Easy interfacing to microprocessors s provided by the atcneo and cecoded multiplexer address nputs and l3tched TTL TRI-STATE*- outputs. The design of the AQC0808. ADC880& has been optimized ay incorporating the most desirable asoects of several Afl3 conversion techniques The ADCD80&. APC383& offers h'gh speed high accuracy, minimal temperature dependence, ex cellent iong-term accuracy and repeatability, and consumes minima! power. These features make this device ideally suited to applications from process and machine control to consumer ana automotive aao ications For 16-channel mul tiplexer wish common o-dtput rsamp e'hold port) see ADC0816 data sheer (See AN-2<s7 'or more nformaticn.i
Features
Easy rtfrtace to ail m preprocessors
Operates rationietricai'y or with 5 V-.0 or analog scar adjusted voltage reference
No zero or fj l-scale adjust required
9-cfiannel multiplexer vvth address logic
QV to 5V input range with single 5V power sups y
Outputs meet TTL voltage level specifications
Standard hermetic or mooed 2&-pin DIP package
2S-p.ii moided ch-p earner package
ADCOSC equivalent to MM74C&49
AOCOati equivalent to MM74C949-1
Key Specifications
Resolution
Total unadjusted Error
Singe Supply
Low Power
Conversion Time
Block Diagram
O l
TUHF tore*
3
IDT
IE
IE
, .. 4.1.1.1 **IJW'L> UL K" J
11 111 lil
See Ordering Information
Connection Diagrams
Molded Chip Carrier Package
Dual-In-Line Package s a a
< < <



I I I 1 1 I 1
Hi- 1 JR u ,>i 70
fi* r iM wr,_ : in
3 -M IH- 11
we- 4 n -*C0 * M2- ::t lg r "miW
K- 5 '.'4 -* e 1 1
sr " - F. IS - 0 r *U_ ; 14
EOC- 7 22 3 13
!->- 8 21 -2"'MSB 4 - ' ir( >
WTPUT tHlfet-CLOCk - n
RS S; F B ; 10 1!
IC
-r5 1 1 1 1 1 1
p, a
11 o _ .-4 * S " Z ,-j
' if< >- w ' 7 -r'TSA a!
CND- 12 !T VHF <") 1
7"-'- ir -r'
Order Number ADC 0808C CV orADC0609C



See HS Package V28A
Order number ADC0808CCN or ADC0809CCN See US Package J28A or M28A
Ordering Information
TEMPERATURE RANGE -40" C to +85'C -55'C to +126X
Error '/i LSB Ursaojjsted ADC0803CCN' AJ5CQ3CSCCV ADC06G3CCJ ADC0303CJ
1 LSB Unadjusted ADCOSOilCCi! ADC03SSCCV
p ackage Ciitire f.I&A N'.olcec DIP V2A Molded Chic :."arrer J38A Cerarvi c DIP J2SA Ceramic CIP
Timing Diagram
.._*4 s*-fic A@B U
a
- Jt
I
IRf J"
HHTt R*>H -a*DDI! :
X
X
a u fin
1
>
Functional Description
Multiplexer, The dev ce certains an 8-channel singe-ended analog signal mtntip exer. A particular input channel is se-ected by using the address oecocer Tah<e Shows the input states for the address lines to select any channel The ad dress is latched into the decoder on the ow-to-high transition of the address latc.n enab'e signa,
TABLE 1.
SELECTED ANALOG CHANNEL ADDRESS LIME
C B A
INP L L L
INI L L H
IN2 L - L
IN3 L :-; H
IN4 H L L
IM5 H L H
IN6 H H L
IN7 H H H
CONVERTER CHARACTERISTICS The Converter
The heart of this singe chip data acquisition system * its 3-bit ana.og-to-digita converter. The converter s des gneti to give fast, accurate, and reoeataole conversions over a wide range of temperatures. The converter s partitioned into 3 major sections: the 2S6R ladder network, the successive ap proximation register, and the comparator The convener's digital outputs are positive true
The 256R adder network approach (Figure ! was chosen over the conventional R/2R adoer because of its Inherent monotonicity. which guarantees no missing d gita codes. Monotonicity is part cu any important in closed loop feedback controisystems Anon-monotomcrelationshipcan cause os-cii ations that will be catastroph c for the system. Additionally, the 256R network does not cause load variations or, the ref erence voltage.
The bottom resistor and the top res-stcr of the ladder net work in Figure > are not the same value as the remainder of the network. The difference in these resistors causes the output characteristic to m symmetrical wth the zero and full-scaie ooints of the transfer curve The f rst output trans -ton occurs when the analog signal has reached + 1* LSB and succeed ng output transitions occur every 1 LSB ater up to fit -sea e
The successive approximation reg.ster (SAR) performs 8 it erations to approximate the input voltage. For any SAR type converter, n-iteratons are required for an n-brt converter. Figure 2 shows 3 typical example of a 3-bit converter. In fie ADC0803. ADC0809. the approximator technique is ex tended to 8 bits using the 256R network.
The AID convener's successive appro-nation register (SAR) is reset on the positive edge of the start conversion (SCI pulse. The conversion is begun on the failing edge of the start conversion pu'M.A conversion n process w I be in-terrupted by rece pt of a re*' star conversion puse. Con tinuous conversion may oe accomplished by tying the end-of-conversion i'EOC; output to the SC input. If used in this mode, an external start conversion pulse should be ap plied after power up Eno-of-eonversion wit go ew between 0 arc 8 clock pu see after the rising edge of start conversion. The most important section of the A/D converter is the com parator It is this section which is resp-orsieie for the ultimate accuracy of the em re converter it is also the comparator dnft which has the greatest influence on the reoeataWity of the device. A chopper-stabilized comparator provides the most effective method of satisfying a:I the converter require ments
The chopper-stabi izeo comparator converts the DC input s'gnal into an AC signal. This signal is then fed through a high gain AC amp ifier ana has tie DC eve restored. This technique limits the dnft component of the amplifier since the dnft is a DC component which is not passed by the AC am plifier. This makes the entire A/D converter extreme y insen-s'tive to temperature long term dnft and input offset errors. Figure J shows a typical error curve for the ADC2808 as measured using the procedures outlined in AN-173.
Applications Information (Continued!
4.0 ANALOG COMPARATOR INPUTS The dynamic comparator nput current caused by the pe riodic switching of on-chip stray capacitances. These are connected alternately to tte output of the resistor ladder: sw ten tree networK end to the comparator input as part of the operation of the choppe' stabilized comparator.
The average value of the comparator input current varies di rectly with clock frequency and with V,N as shown in Fiaure 6.
If no filter capacitors are used at the ana g inputs signal source impedances are low, the comparator it rent shou-.O not introduce converter errors, as the i created by the capacitance discharge w*l cie out ix comparator output is strobed. If insut filter capacJors are desires for noise reouc signal conditioning they wi I tend to average out the comparator input current. It wil then take on the cha tics o* a DC bias current whose effect can be predic vents5naKy.
Typical Application
READ
AODFLESS DECODE- I.AB*-ft0t5r
3>
5V STLPPI.V'1
GRuuMO
CLK OF
UREFI<; IQC.
vntn i
7 '
SIAJU =, -'>
2 -
ALT N ]
2 '
J
L
A ' '
AUEOMB
B ADC080!) 2-6
c 1 7
z *
a
G M D
*


IKTERWHT
r^'IP^x* n:i" 1
-#>INIERHUPT
MS 6
DIB > DBb - DS4
1)83 - DS2 -OBI
-> am
B-$V
ANALOG INPUT RANEE
'Ada-ess
jh -teed*: fcr 838J aw SOVB imrfecinsADCKCi tc a n '-:cro:es*:r
Features
Compatible with MCS-51* Products
4K Bytes of In-Systetn Programmable (ISP) Flash Memory
- Endurance: 1000 Write/Erase Cycles
4.0V to 5.5V Operating Range
Fully Static Operation: 0 Hz to 33 MHz
Three-level Program Memory Lock
128 x 8-bit Internal RAM
32 Programmable I/O Lines
Two 15-bit Timer/Counters
Six Interrupt Sources
Full Duplex UART Serial Channel
Low-power Idle and Power-down Modes
Interrupt Recovery from Power-down Mode
Watchdog Timer
Dual Data Pointer
Power-off Flag
Fast Programming Time
Flexible ISP Programming (Byte and Page Mode)
Description
The AT89S51 is a low-power, high-performance CMOS 8-bit microcontroller with 4K bytes of in-systen programmable Flash memory. The device is manufactured using Atmel's high-density nonvolatile memory technology and is compatible with the indus try-standard 80C51 instruction set and pinout The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory pro grammer By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S5I is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.
The AT89S51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM. 32 I/O lines, Watchdog timer, two data pointers, two 18-bit timer/counters, a five-vector two-level interrupt architecture, a fuM duplex serial port, on-chip oscillator, and clock circuitry In addition, the ATS9S51 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 con tents but freezes the oscillator, disabling all other chip functions until the next external interrupt or hardware reset
8-bit
Microcontroller with 4K Bytes In-System Programmable Flash
AT89S51
Pin Configurations
PDIP
PI.CC Pl.t c P1.2C P1.3C
= 4C
lIVOS irt.SC
RVIOC. = -: c
RSTC
IRXCI =s.:-c
iTXC-i P3.- C (INTO) P3.2 C JIRTTj = ;.. C
4 c
itVPp - if R
XTAU2 I; XTAU R G\C I
34
24
VCC
PC .of ADO:
PC". 1 CADI:
PC.2i.A02;
P0.3 AD3)
PC.4 AD4;
PC 5 ;AD5]
PC .6 lADBr
PC.7 AD7;
E.-V==
A.-E-SSQG
P5EN
P2.7 i.Aie! 3P2.6 A14;
P2.5 A1J) 1P2.4 >AV2) J P2.3 A11> J P2.2 iA10) 1P2.1 iAS; "]P2.0 I A3;
Block Diagram
AA AA
+ I 11 L {1 F ,
=OR" 0 DRIVERS
POR" 2 DRIVERS
l-IAM 6.0 Oil
nut IS ILK
2 -x
i _ , I , r
STACK -OltrE.R
PROGRAM RE SISTER
UTERR JP SESIAL PORT *NC T teR BLOCKS
PROGRAM COUNTER
3SEN ALSPROG *
AND
CONTROL
rii Ruc"ic.
REGISTER
WATCH
DOG
SORT 3
LATCH
i
r
PORT 3 DRIVERS
RTTITTF AA A A i i 4
Pin Description
VCC Supply voltage.
GND Ground.
Port 0 Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can sink eight
TTL inputs. When Is are written to port 0 pins, the pins can be used as high-impedance inputs.
Fort 0 can also be configured to be the multiplexed low-order address'data bus during accesses to externa! program and data memory. In this mode, PO has internal pull-ups.
Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pull-ups are required during program verification
Port 1 Port I is an 8-bit bidirectional I/O port with internal puil-jps. The Port 1 output buffers can
sink/source four TTL inputs. When 1s are written to Port I pins, they are pulled high by the interna! pull-ups ana can be usee as inputs As inputs. Port I pins that are externally being pulled low will source current (lfLi oecause of the interna! pull-ups.
Port 1 also receives the low-order address bytes during Flash programming and verification
Port Pin Alternate Functions
PI.5 MCSI iuseci for In-System Programming}
PI 6 MISO fused for h-System Programming)
PI .7 SCK (used for In-System Programming;
Port 2 Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 2 output buffers can
sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs. Port 2 pins that are externally being pulled low will source current (l,,J because of the interna! pull-ups.
Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external oata memory that use 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external oata memory that use 8-bit addresses (MOVX @ R ). Port 2 emits the contents of the P2 Spe cial Function Register,
Port 2 also receives the high-order address bits and some control signals during Flash pro gramming and verification.
Port 3 Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output Duffers can
sink/source four TTL inputs. When Is are written to Port 3 pins, they are pulled high by the internal pull-ups and can be used as inputs As inputs. Port 3 pins that are externally being pulled tow will source current (y because of the pull-ups.
Port 3 receives some control signals for Flash programming and verification.
Port 3 also serves the functions of various special features of the AT89S51. as shown in the following table.
Port Pin Alternate Functions
P30 RXD <senal input ports
P3J TXD (senal output port)
P3 2 INTO (external interrupt 0)
P3.3 INT 1 (external interrupt i j
P3.4 TO (timer 0 external input i
P3.5 T1 (timer 1 external input)
P3.6 WR {external data memory write strode;
P3 7 W) (external data memory read strobe)
RST
Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives High for 98 oscillator periods after the Watchdog times out The DIS-RTO bit in SFR AUXR (address SEHi can oe used to disable this feature In the default state of bit DISRTO, the RESET HIGH out feature is enabled.
ALE/PROG
Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.
In normal operation. ALE is emitted at a constant rate of 1/6 the oscillator frequency and may oe used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory
If desired. ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction Otherwise, the pin is weakly pulled high Setting the ALE-oisab e bit has no effect if the microcontroller is in external execution mode.
PSEN
Program Store Enable (PSEN) is the read strobe to external program memory
When the AT8&S51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.
EA/VPP
Externa! Access Enable. EA must be strapped to GND in order to enable the device to fetch code from externa! program memory locations starting at 0000H up to FFH. Note, however, that if lock bit 1 is programmed, EA will be infernally latched on reset.
EA should be strapped to Vcc for internal program executions.
This pin also receives the 12-voft programming enable voltage (Vpp) during Flash programming.
EAjV,
LOG C 3
(ENABLE)
P3.Q i'RDY/BSYI
surf
Y R=ACV
Flash Memory Sena: Down oading
ATI9S51
O
V
INSTRUCTION
IHPUT *
DATA CHJTPJT *
CLOCK IN
Pl.c.'MOSi
pi.e/wiso
P1.7,'SCK XTAU
3-33 MHz
XTAL1 GND
Flash Programming and Verification Waveforms - Serial Mode
, Serial Programming Waveforms
SERIAL DATA INPUT / MSB V V V V Y V Y -35
=i,s I;mosi. L T, ./v.. /v_ .j\ A _A A
Wi DATA OUTPUT / Mk Y Y"" Y Y Y V Y i.sa \
PI.6SMISOJ z ,}.,.. /v., A _A._ A -A A. !
S5RIAL COCK INPUT Pi.7 iSCK'i
I I I I
rij'L l ii run.
MAX232. MAX232I DUAL EIA-232 DRIVERS/RECEIVERS
SLLS:-7l-FESRbA=< r 133=1 - F.E .'!SEI> OCTC3ER-302
T1IN
T2IN
R10UT
R20UT
11
10
12
[>> [>
<<r
14
13
T10UT
T20IJT
R1IN
R2IN
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)t
Input supply voltage range. Vcc (see Note I) - -0.3 V to 6 V
Positive output supply voltage range. Vg+ Vcc - 0.3 V to 15 V
Negative output supply voltage range V'g_ -0.3 V to-15 V
Input voltage range, V : Driver -0.3 V to V'cc + 0.3 V
Receiver +30 V
Output voltage range, V0: T iOUT, T20UT Vs_- 0.3 V to Vg+ < 0.3 V
R10UT. R20UT . -0.3 V to Vcc + 0.3 V
Short-circuit duration: T10UT. T20UT ^Unlimited
Package thermal impedance, ftj^ (see Note 2): D package 73XAV
DW package 57"CAV
N package e7 C/W
NS package 64'C/W
Lead temperature 1.6 mm (1/16 inch) from case for 10 seconds 2QQ'JC
Storage temperature range, Tstq -65 C to 150:C
REFERENCE
1) google.com
2) redcircuits.com
3) efy.com
4) ELECTRONICS FOR YOU MAGAZINE
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#2
please kindly send thefull documentation on tis topic with presentation.
@sireesha,ee[/size][/font]
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