Weather Monitoring Using Rf
Transcript of Weather Monitoring Using Rf
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ABSTRACT
The project deals with the design and development of hardware and software for
eight channelweather monitoringsystem.
A weather monitoring(also data logger ordata recorder) is an electronic device
that records data over time or in relation to location either with a built in instrument or
sensor or by using external instruments and sensors. One of the primary advantages of
using these data loggers is the ability to automatically and continuously collect data on a
24-hour basis.
The data which are recorded continuously in this project are Temperature, Intensity.
These analog quantities are taken and converted into corresponding digital values using an
eight channel ADC. These converted digital values are transmitted from the
microcontroller using RF transmitter and an encoder. These same values are received at the
receiver end using RF receiver and a decoder.
The RF modules used here are STT-433 MHz Transmitter, STR-433 MHz
Receiver, HT640 RF Encoder and HT648 RF Decoder. The processed data from ADC is
sent to microcontroller. The microcontroller passes this data to the RF transmitter through
RF Encoder. The encoder continuously receives the data from the microcontroller, passes
the data to the RF transmitter and the transmitter transmits the data. The encoder encodes
the 8-bit data into a single data and then presents it to RF transmitter.
At the receiving end, the RF receiver receives this data, gives it to RF decoder. This
decoder converts the single bit data into 8-bit data and presents it to the microcontroller.
Now, it is the job of the controller to read the data and display the same data on LCD.
CHAPTER 1
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INTRODUCTION
The project deals with the design and development of hardware and software for
eight channel weather monitoringsystem.
A weather monitoring(also data logger ordata recorder) is an electronic device
that records data over time or in relation to location either with a built in instrument or
sensor or by using external instruments and sensors. One of the primary advantages of
using these data loggers is the ability to automatically and continuously collect data on a
24-hour basis.
The data which are recorded continuously in this project are Temperature, Intensity.
These analog quantities are taken and converted into corresponding digital values using an
eight channel ADC. These converted digital values are transmitted from the
microcontroller using RF transmitter and an encoder. These same values are received at the
receiver end using RF receiver and a decoder.
The RF modules used here are STT-433 MHz Transmitter, STR-433 MHz
Receiver, HT640 RF Encoder and HT648 RF Decoder. The processed data from ADC is
sent to microcontroller. The microcontroller passes this data to the RF transmitter through
RF Encoder. The encoder continuously receives the data from the microcontroller, passes
the data to the RF transmitter and the transmitter transmits the data. The encoder encodes
the 8-bit data into a single data and then presents it to RF transmitter.
At the receiving end, the RF receiver receives this data, gives it to RF decoder. This
decoder converts the single bit data into 8-bit data and presents it to the microcontroller.
Now, it is the job of the controller to read the data and display the same data on LCD.
CHAPTER2
EMBEDDED SYSTEMS
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An embedded system can be defined as a computing device that does a specific
focused job. Appliances such as the air-conditioner, VCD player, DVD player, printer, fax
machine, mobile phone etc. are examples of embedded systems. Each of these appliances
will have a processor and special hardware to meet the specific requirement of the
application along with the embedded software that is executed by the processor for meeting
that specific requirement. The embedded software is also called firm ware. The
desktop/laptop computer is a general purpose computer. You can use it for a variety of
applications such as playing games, wordprocessing, accounting, software development
and so on. In contrast, the software in the embedded systems is always fixed listed below:
Embedded systems do a very specific task, they cannot be programmed to do
different things. . Embedded systems have very limited resources, particularly the memory.
Generally, they do not have secondary storage devices such as the CDROM or the floppy
disk. Embedded systems have to work against some deadlines. A specific job has to be
completed within a specific time. In some embedded systems, called real-time systems, the
deadlines are stringent. Missing a deadline may cause a catastrophe-loss of life or damage
to property. Embedded systems are constrained for power. As many embedded systems
operate through a battery, the power consumption has to be very low.
2.1 Application Areas
Nearly 99 per cent of the processors manufactured end up in embedded systems.
The embedded system market is one of the highest growth areas as these systems are used
in very market segment- consumer electronics, office automation, industrial automation,
biomedical engineering, wireless communication, data communication,
telecommunications, transportation, military and so on.
2.1.1 Consumer appliances
At home we use a number of embedded systems which include digital camera,
digital diary, DVD player, electronic toys, microwave oven, remote controls for TV and
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air-conditioner, VCO player, video game consoles, video recorders etc. Todays high-tech
car has about 20 embedded systems for transmission control, engine spark control, air-
conditioning, navigation etc. Even wristwatches are now becoming embedded systems.
2.1.2Office automation
The office automation products using em embedded systems are copying machine,
fax machine, key telephone, modem, printer, scanner etc.
2.1.3Industrial automation
Today a lot of industries use embedded systems for process control. These include
pharmaceutical, cement, sugar, oil exploration, nuclear energy, electricity generation and
transmission. The embedded systems for industrial use are designed to carry out specific
tasks such as monitoring the temperature, pressure, humidity, voltage, current etc., and then
take appropriate action based on the monitored levels to control other devices or to send
information to a centralized monitoring station.
2.1.4Medical electronics
Almost every medical equipment in the hospital is an embedded system. These
equipments include diagnostic aids such as ECG, EEG, blood pressure measuring
devices, X-ray scanners; equipment used in blood analysis, radiation, colonoscopy,
endoscopy etc. Developments in medical electronics have paved way for more accurate
diagnosis of diseases.
2.1.5 Computer networking
Computer networking products such as bridges, routers, Integrated Services Digital
Networks (ISDN), Asynchronous Transfer Mode (ATM), X.25 and frame relay switches
are embedded systems which implement the necessary data communication protocols. For
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example, a router interconnects two networks. The two networks may be running different
protocol stacks. The routers function is to obtain the data packets from incoming pores,
analyze the packets and send them towards the destination after doing necessary protocol
conversion. Most networking equipments, other than the end systems (desktop computers)
we use to access the networks, are embedded systems
2.1.6 Telecommunications
In the field of telecommunications, the embedded systems can be categorized as
subscriber terminals and network equipment. The subscriber terminals such as key
telephones, ISDN phones, terminal adapters, web cameras are embedded systems. The
network equipment includes multiplexers, multiple access systems, Packet Assemblers
Dissemblers (PADs), sate11ite modems etc. IP phone, IP gateway, IP gatekeeper etc. are
the latest embedded systems that provide very low-cost voice communication over the
Internet.
2.1.7 Wireless technologies
Advances in mobile communications are paving way for many interesting
applications using embedded systems. The mobile phone is one of the marvels of the last
decade of the 20h century. It is a very powerful embedded system that provides voice
communication while we are on the move
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2.2 Overview of Embedded System Architecture
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Every embedded system consists of custom-built hardware built around a Central
Processing Unit (CPU). This hardware also contains memory chips onto which the
Fig2.2 (a): layered Architecture of Embedded system
Software is loaded. The software residing on the memory chip is also called the
firm ware The embedded system architecture can be represented as a layered architecture
as shown in Fig.
The operating system runs above the hardware, and the application software runs
above the operating system. The same architecture is applicable to any computer including
a desktop computer. However, there are significant differences. It is not compulsory to
have an operating system in every embedded system. For small appliances such as remote
control units, air conditioners, toys etc., there is no needforan operating system and you
can write only the software specific to that application. Once the software is transferred
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to the memory chip, the software will continue to runfora long time you dont need to
reload new software.
Now, let us see the details of the various building blocks of the hardware of an embedded
system. As shown in Fig. the building blocks are;
Central Processing Unit (CPU)
Memory (Read-only Memory and Random Access Memory)
Input Devices
Output devices
Communication interface
Application-specific circuitry
Fig2.2 (b): building blocks of the hardware of an embedded system
2.2.1 Central Processing Unit (CPU)
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The Central Processing Unit (processor, in short) can be any of the following:
microcontroller, microprocessor or Digital Signal Processor (DSP). A micro-controller is a
low-cost processor. Its main attraction is that on the chip itself, there will be many other
components such as memory, serial communication interface, analog-to digital converter
etc. So, for small applications, a micro-controller is the best choice as the number of
external components required will be very less. On the other hand, microprocessors are
more powerful, but you need to use many external components with them. D5P is used
mainly for applications in which signal processing is involved such as audio and video
processing.
2.2.2 Memory
The memory is categorized as Random Access 11emory (RAM) and Read Only
Memory (ROM). The contents of the RAM will be erased if power is switched off to the
chip, whereas ROM retains the contents even if the power is switched off. So, the firmware
is stored in the ROM. When power is switched on, the processor reads the ROM; the
program is program is executed.
2.2.3 Input devices
Unlike the desktops, the input devices to an embedded system have very limited
capability. There will be no keyboard or a mouse, and hence interacting with the embedded
system is no easy task. Many embedded systems will have a small keypad-you press one
key to give a specific command. A keypad may be used to input only the digits. Many
embedded systems used in process control do not have any input deviceforuser
interaction; they take inputsfrom sensors or transducers 1fnd produce electrical signals
that are in turn fed to other systems.
2.2.4 Output devices
The output devices of the embedded systems also have very limited capability.8
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Some embedded systems will have afew Light Emitting Diodes (LEDs) to indicate the
health status of the system modules, orforvisual indication of alarms. A small Liquid
Crystal Display (LCD) may also be used to displaysome important parameters.
2.2.5Communication interfaces
The embedded systems may need to, interact with other embedded systems at they
may have to transmit data to a desktop. To facilitate this, the embedded systems are
provided with one or a few communication interfaces such as RS232, RS422, RS485,
Universal Serial Bus (USB), IEEE 1394, Ethernet etc.
2.2.6 Application-specific circuitry
Sensors, transducers, special processing and control circuitry may be required fat an
embedded system, depending on its application. This circuitry interacts with the processor
to carry out the necessary work. The entire hardware has to be given power supply either
through the 230 volts main supply or through a battery. The hardware has to design in such
a way that the power consumption is minimized
CHAPTER 3
HARDWARE IMPLEMENTATION OF THE PROJECT
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This chapter briefly explains about the Hardware Implementation of the project. It
discusses the design and working of the design with the help of block diagram and circuit
diagram and explanation of circuit diagram in detail. It explains the features, timer
programming, serial communication, interrupts of AT89S52 microcontroller. It also
explains the various modules used in this project.
3.1 Project Design
The implementation of the project design can be divided in two parts.
Hardware implementation
Firmware implementation
Hardware implementation deals in drawing the schematic on the plane paper
according to the application, testing the schematic design over the breadboard using the
various ICs to find if the design meets the objective, carrying out the PCB layout of the
schematic tested on breadboard, finally preparing the board and testing the designed
hardware.
The firmware part deals in programming the microcontroller so that it can control
the operation of the ICs used in the implementation. In the present work, we have used the
Orcad design software for PCB circuit design, the Keil v3 software development tool to
write and compile the source code, which has been written in the C language. The Proload
programmer has been used to write this compile code into the microcontroller. The
firmware implementation is explained in the next chapter.
The project design and principle are explained in this chapter using the block
diagram and circuit diagram. The block diagram discusses about the required components
of the design and working condition is explained using circuit diagram and system wiring
diagram.
3.2 INTRODUCTION TO MICROCONTROLLER
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Based on the Processor side Embedded Systems is mainly divided into 3 types
1. Micro Processor : - are for general purpose eg: our personal computer
2. Micro Controller:- are for specific applications, because of cheaper cost we will gofor these
3. DSP (Digital Signal Processor):- are for high and sensitive application purpose
3.3 MICROCONTROLLER VERSUS MICROPROCESSOR
A system designer using a general-purpose microprocessor such as the Pentium or
the 68040 must add RAM, ROM, I/O ports, and timers externally to make them functional.
Although the addition of external RAM, ROM, and I/O ports makes these systems bulkier
and much more expensive,
A Microcontroller has a CPU (a microprocessor) in addition to a fixed amount of
RAM, ROM, I/O ports, and a timer all on a single chip. In other words, the processor, the
RAM, ROM, I/O ports and the timer are all embedded together on one chip; therefore, the
designer cannot add any external memory, I/O ports, or timer to it.
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Fig3.3 (a): Block diagram of microprocessor
Fifffffffff
Fig3.3 (b): Block diagram of microcontroller
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MICRO CONTROLLER: is a chip through which we can connect many other devices
and also those are controlled by the program the program which burn into that chip
3.4 Block Diagram of the Project and its Description
The block diagram of the design is as shown in Fig 3.4. It consists of power supply
unit, microcontroller, sensor module, ADC, LCD, and the cooling system with its driver
circuit. The brief description of each unit is explained as follows
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Transmitter section
Fig3.4 (a): block diagram of the project and its description
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Receiver section
Fig3.4 (b): block diagram of the project and its description
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3.4.1 Power Supply
The input to the circuit is applied from the regulated power supply. The a.c. input
i.e., 230V from the mains supply is step down by the transformer to 12V and is fed to a
rectifier. The output obtained from the rectifier is a pulsating d.c voltage. So in order to get
a pure d.c voltage, the output voltage from the rectifier is fed to a filter to remove any a.c
components present even after rectification. Now, this voltage is given to a voltage
regulator to obtain a pure constant dc voltage.
Fig3.4.1 (a): components of a regulated power supply
3.4.2 Transformer
Usually, DC voltages are required to operate various electronic equipment and
these voltages are 5V, 9V or 12V. But these voltages cannot be obtained directly. Thus the
a.c input available at the mains supply i.e., 230V is to be brought down to the required
voltage level. This is done by a transformer. Thus, a step down transformer is employed to
decrease the voltage to a required level.
3.4.3 Rectifier
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The output from the transformer is fed to the rectifier. It converts A.C. into pulsating D.C.
The rectifier may be a half wave or a full wave rectifier. In this project, a bridge rectifier is
used because of its merits like good stability and full wave rectification.
3.4.4 Filter
Capacitive filter is used in this project. It removes the ripples from the output of
rectifier and smoothens the D.C. Output received from this filter is constant until the mains
voltage and load is maintained constant. However, if either of the two is varied, D.C.
voltage received at this point changes. Therefore a regulator is applied at the output stage.
3.4.5 Voltage regulator
As the name itself implies, it regulates the input applied to it. A voltage regulator is
an electrical regulator designed to automatically maintain a constant voltage level. In this
project, power supply of 5V and 12V are required. In order to obtain these voltage levels,
7805 and 7812 voltage regulators are to be used. The first number 78 represents positive
supply and the numbers 05, 12 represent the required output voltage levels.
3.4.6 Microcontrollers
Fig3.4.7 (a):8051 microcontroller
Microprocessors and microcontrollers are widely used in embedded systems
products. Microcontroller is a programmable device. A microcontroller has a CPU in
addition to a fixed amount of RAM, ROM, I/O ports and a timer embedded all on a single
chip. The fixed amount of on-chip ROM, RAM and number of I/O ports in
microcontrollers makes them ideal for many applications in which cost and space are
critical.
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The Intel 8051 is Harvard architecture, single chip microcontroller (C) which was
developed by Intel in 1980 for use in embedded systems. It was popular in the 1980s and
early 1990s, but today it has largely been superseded by a vast range of enhanced devices
with 8051-compatible processor cores that are manufactured by more than 20 independent
manufacturers including Atmel, Infineon Technologies and Maxim Integrated Products.
8051 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at
a time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by th
CPU. 8051 is available in different memory types such as UV-EPROM, Flash and NV-
3.4.7 Features of AT89S51
8K Bytes of Re-programmable Flash Memory.
RAM is 256 bytes.
4.0V to 5.5V Operating Range.
Fully Static Operation: 0 Hz to 33 MHzs
Three-level Program Memory Lock.
256 x 8-bit Internal RAM.
32 Programmable I/O Lines.
Three 16-bit Timer/Counters.
Eight 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.
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3.4.8 Description
The AT89S52 is a low-voltage, high-performance CMOS 8-bit microcomputer with
8K bytes of Flash programmable memory. The device is manufactured using Atmels high
density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. The on chip flash allows the program memory to be reprogrammed in
system or by a conventional non volatile memory programmer. By combining a versatile 8-
bit CPU with Flash on a monolithic chip, the Atmel AT89s52 is a powerful microcomputer,
which provides a highly flexible and cost-effective solution to many embedded control
applications.
In addition, the AT89S52 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.
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Fig3.4.9 (a): pin diagram of 8052
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Fig3.4.9 (b): block diagram of 8052
3.4.9 Pin description
Vcc Pin 40 provides supply voltage to the chip. The voltage source is +5V.
GND: Pin 20 is the ground
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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 1s are written to port 0 pins, the pins can be used as high
impedance inputs. Port 0 can also be configured to be the multiplexed low-order
address/data bus during accesses to external program and data memory. In this mode, P0
has internal pull-ups.
.Port 1
Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output
buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled
high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are
externally being pulled low will source current (IIL) because of the internal pull-ups. In
addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input
(P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the
following table.
Table
Port 2
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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 (IIL) because of the internal pull-ups. Port 2
emits the high-order address byte during fetches from external program memory and during
accesses to external data memory that uses 16-bit addresses (MOVX @ DPTR). In this
application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to
external data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of
the P2 Special Function Register. The port also receives the high-order address bits and
some control signals during Flash programming and verification.
Port 3Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output buffers can
sink/source four TTL inputs. When 1s 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 low will source current (IIL)
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 AT89S52, as shown in the
following table.
Table (2)
RST
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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 DISRTO bit in SFR AUXR (address 8EH) can be 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 be 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-disable bit has no effect if the microcontroller is
in external execution mode.
PSENProgram Store Enable: (PSEN) is the read strobe to external program memory.
When the AT89S52 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
External Access Enable
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EA must be strapped to GND in order to enable the device to fetch code from
external program memory locations starting at 0000H up to FFFFH. Note,
however, that if lock bit 1 is programmed, EA will be internally latched on
reset.
XTAL1:Input to the inverting oscillator amplifier and input to the internal clock
operating circuit.
XTAL2:
Output from the inverting oscillator amplifier
Fig3.4.10 (a): oscillator connection
Fig3.4.10 (b): External clock drive connection
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XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier
that can be configured for use as an on-chip oscillator. Either a quartz crystal or ceramic
resonator may be used. To drive the device from an external clock source, XTAL2 should
be left unconnected while XTAL1 is driven. There are no requirements on the duty cycle of
the external clock signal, since the input to the internal clocking circuitry is through a
divide-by-two flip-flop, but minimum and maximum voltage high and low time
specifications must be observed.
3.5 Special Function Registers
A map of the on-chip memory area called the Special Function Register (SFR)
space is shown in the following table.
It should be noted that not all of the addresses are occupied and unoccupied
addresses may not be implemented on the chip. Read accesses to these addresses will in
general return random data, and write accesses will have an indeterminate effect.
User software should not write 1s to these unlisted locations, since they may be
used in future products to invoke new features. In that case, the reset or inactive values of
the new bits will always be 0.
3.5.1 Timer 2 Registers
Control and status bits are contained in registers T2CON and T2MOD for Timer 2.
The register pair (RCAP2H, RCAP2L) is the Capture/Reload register for
Timer 2 in 16-bit capture mode or 16-bit auto-reload mode.
3.5.2 Interrupt Registers
The individual interrupt enable bits are in the IE register. Two priorities can be set
for each of the six interrupt sources in the IP register.
3.5.3 Dual Data Pointer Registers
To facilitate accessing both internal and external data memory, two banks of 16-bit
Data Pointer Registers are provided: DP0 at SFR address locations 82H-83H and DP1 at
84H and 85H. Bit DPS = 0 in SFR AUXR1 selects DP0 and DPS = 1 selects DP1.
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3.5.4 Power off Flag
The Power off Flag (POF) is located at bit 4 (PCON.4) in the PCON SFR. POF is
set to 1 during power up. It can be set and rest under software control and is not affected
by reset.
3.5.5 Watchdog Timer (One-time Enabled with Reset-out)
The WDT is intended as a recovery method in situations where the CPU may be
subjected to software upsets. The WDT consists of a 14-bit counter and the Watchdog
Timer Reset (WDTRST) SFR. The WDT is defaulted to disable from exiting reset. To
enable the WDT, a user must write 01EH and 0E1H in sequence to the WDTRST register
(SFR location 0A6H).
When the WDT is enabled, it will increment every machine cycle while the
oscillator is running. The WDT timeout period is dependent on the external clock
frequency. There is no way to disable the WDT except through reset (either hardware reset
or WDT overflow reset). When WDT overflows, it will drive an output RESET HIGH
pulse at the RST pin.
3.5.6 UART
The Atmel 8051 Microcontrollers implement three general purpose, 16-bit timers/
counters. They are identified as Timer 0, Timer 1 and Timer 2 and can be independently
configured to operate in a variety of modes as a timer or as an event counter. When
operating as a timer, the timer/counter runs for a programmed length of time and then
issues an interrupt request.
A basic operation consists of timer registers THx and TLx (x= 0, 1) connected in
cascade to form a 16-bit timer. Setting the run control bit (TRx) in TCON register turns the
timer on by allowing the selected input to increment TLx. When TLx overflows it
increments THx; when THx overflows it sets the timer overflow flag (TFx) in TCON
register. Setting the TRx does not clear the THx and TLx timer registers. Timer registers
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can be accessed to obtain the current count or to enter preset values. They can be read at
any time but TRx bit must be cleared to preset their values, otherwise the behavior of the
timer/counter is unpredictable.
The C/T control bit (in TCON register) selects timer operation or counter operation,
by selecting the divided-down peripheral clock or external pin Tx as the source for the
counted signal. TRx bit must be cleared when changing the mode of operation, otherwise
the behavior of the timer/counter is unpredictable. For timer operation (C/Tx# = 0), the
timer register counts the divided-down peripheral clock. The timer register is incremented
once every peripheral cycle (6 peripheral clock periods). The timer clock rate is FPER / 6,
i.e. FOSC / 12 in standard mode or FOSC / 6 in X2 mode. For counter operation (C/Tx# =
1),
Since it takes 2 cycles (12 peripheral clock periods) to recognize a negative
transition, the maximum count rate is FPER / 12, i.e. FOSC / 24 in standard mode or FOSC
/ 12 in X2 mode. There are no restrictions on the duty cycle of the external input signal, but
to ensure that a given level is sampled at least once before it changes, it should be held for
at least one full peripheral cycle. In addition to the timer or counter selection, Timer 0
and Timer 1 have four operating modes from which to select which are selected by bit-
pairs (M1, M0) in TMOD. Modes 0, 1and 2 are the same for both timer/counters. Mode 3
is different.
The four operating modes are described below. Timer 2, has three modes of
operation: capture, auto-reload and baud rate generator.
3.6 Crystal Oscillator
The 8051 uses the crystal for precisely that: to synchronize its operation.
Effectively, the 8051 operates using what are called "machine cycles." A single machine
cycle is the minimum amount of time in which a single 8051 instruction can be executed.
Although many instructions take multiple cycles. 8051 has an on-chip oscillator. It needs
an external crystal that decides the operating frequency of the 8051. The crystal is
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connected to pins 18 and 19 with stabilizing capacitors. 12 MHz (11.059MHz) crystal is
often used and the capacitance ranges from 20pF to 40pF.
A cycle is, in reality, 12 pulses of the crystal. That is to say, if an instruction takes
one machine cycle to execute, it will take 12 pulses of the crystal to execute. Since we
know the we can calculate how many instruction cycles the 8051 can execute per second:
11,059,000 / 12 = 921,583
11.0592 MHz crystals are often used because it can be divided to give you exact clock rates
for most of the common baud rates for the UART, especially for the higher speeds (9600,
19200).
Fig3.6 (a): block diagram of crystal oscillator
3.7 Reset
RESET is an active High input When RESET is set to High, 8051 goes back to the
power on state. The 8051 is reset by holding the RST high for at least two machine cycles
and then returning it low. Initially charging of capacitor makes RST High, When capacitor
charges fully it blocks DC.
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Fig3.7 (a): diagram of reset
3.8 WHAT ARE THE MAIN REQUIREMENTS FOR THE COMMUNICATION
USING RF
RF Transmitter
RF Receiver
Encoder and Decoder
3.8.1 RF TRANSMITTER STT-433MHz
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Fig3.8.1(a):STT-433 MHz TRANSMITTER
3.8.1.1 FACTORS INFLUENCED TO CHOOSE STT-433MHz
ABOUT THE TRANSMITTER
The STT-433 is ideal for remote control applications where low cost and longerrange is required.
The transmitter operates from a1.5-12V supply, making it ideal for battery-powered
applications.
The transmitter employs a SAW-stabilized oscillator, ensuring accurate frequency
control for best range performance.
The manufacturing-friendly SIP style package and low-cost make the STT-433
suitable for high volume applications.
3.8.1.2 Features
433.92 MHz Frequency
Low Cost
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1.5-12V operation
Small size
3.8.2 PIN DESCRIPTION
FIG3.8.2 (a): PIN DISCRIPTION
GND: Transmitter ground:Connect to ground plane
DATA: Digital data input. This input is CMOS compatible and should be driven with
CMOS level inputs.
VCC: Operating voltage for the transmitter. VCC should be bypassed with a .01uF
ceramic capacitor and filtered with a 4.7uF tantalum capacitor. Noise on the power supply
will degrade transmitternoise performance.
ANT: 50 ohm antenna output. The antenna port impedance affects output power and
harmonic emissions. Antenna can be single core wire of approximately 17cm length or
PCBtrace antenna.
3.8.3 APPLICATION
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Fig3.8.3 (a): Connection between the transmitter and microcontroller
The typical connection shown in the above figure cannot work exactly at all times
because there will be no proper synchronization between the transmitter and the
microcontroller unit. i.e., whatever the microcontroller sends the data to the transmitter, the
transmitter is not able to accept this data as this will be not in the radio frequency range.
The encoder used here is HT640 from HOLTEK SEMICONDUCTORS INC.
3.8.4 ENCODER HT640
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Fig3.8.4 (a): PIN DIAGRAM OF HT640 ENCODER
PIN DESCRIPTION:
Table (3)
3.8.5 DEMO CIRCUIT: Transmission Circuit
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Fig3.8.5 (a): Bock diagram of Transmission circuit
The data sent from the microcontroller is encoded and sent to RF transmitter. The
data is transmitted on the antenna pin. Thus, this data should be received on the destination
i.e, on RF receiver.
3.8.6 RF RECEIVER STR-433 MHz
Fig3.8.6 (a): RF RECEIVER STR-433 MHz
The data is received by the RF receiver from the antenna pin and this data is
available on
the datpins . Two Data pins are provided in the receiver module.
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Fig3.8.6 (b): PIN DISCRIPTION OF STR-433
PINOUT
ANT: Antenna input.
GND: Receiver Ground. Connect to ground plane.
VCC (5V): VCC pins are electrically connected and provide operating voltage for the
receiver.
DATA: Digital data output. This output is capable of driving one TTL or CMOS load. It
is a CMOS compatible output.
3.9 HOW DOES THE DECODER WORK?
The 3^18 decoders are a series of CMOS LSIs for remote control system
applications. They are paired with the 3^18 series of encoders.
For proper operation, a pair of encoder/decoder pair with the same number of
address and data format should be selected.
The 3^18 series of decoders receives serial address and data from that series of
encoders that are transmitted by a carrier using an RF medium.
A signal on the DIN pin then activates the oscillator which in turns decodes the
incoming address and data.
The VT pin also goes high to indicate a valid transmission. That will last until the
address code is incorrect or no signal has been received.
The 3^18 decoders are capable of decoding 18 bits of information that consists of N
bits of address and 18N bits of data.
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Fig3.9 (a): flow chart of the decoder work
3.9.1 BASIC APPLICATION CIRCUIT OF HT648L DECODER
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Fig3.9.1 (a): BASIC APPLICATION CIRCUIT OF HT648L DECODER
3.9.2 DEMO CIRCUIT: Reception circuit
Fig3.9.2 (a); block diagram of Reception circuit
The data transmitted into the air is received by the receiver. The received data is
taken from the data line of the receiver and is fed to the decoder .The output of decoder is
given to microcontroller and then data is processed according to the application.
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3.10 Light Dependent Resistor
LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits.
Normally the resistance of an LDR is very high, sometimes as high as 1,000,000 ohms, butwhen they are illuminated with light, the resistance drops dramatically. Thus in this project,
LDR plays an important role in switching on the lights based on the intensity of light i.e., if
the intensity of light is more (during daytime) the lights will be in off condition. And if the
intensity of light is less (during nights), the lights will be switched on.
Fig3.10 (a): Light Dependent Resister
The output of the LDR is given to ADC which converts the analog intensity value into
corresponding digital data and presents this data as the input to the microcontroller
3.10.1 Features
Calibrated directly in Celsius (Centigrade)
Linear + 10.0 mV/C scale factor
0.5C accuracy guaranteed (at +25C)
Rated for full 55 to +150C range
Suitable for remote applications
Low cost due to wafer-level trimming Operates from 4 to 30 volts
Less than 60 A current drain
Low self-heating, 0.08C in still air
Nonlinearity only 14C typical
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Low impedance output, 0.1 W for 1 mA load
3.11 Temperature Sensor (LM35)
LM35 converts temperature value into electrical signals. LM35 series sensors are
precision integrated-circuit temperature sensors whose output voltage is linearlyproportional to the Celsius temperature. The LM35 requires no external calibration since it
is internally calibrated. . The LM35 does not require any external calibration or trimming to
provide typical accuracies of 14C at room temperature and 34C over a full 55 to
+150C temperature range.
Fig3.11 (a): diagrams of LM35
3.11.1 The characteristic of this LM35 sensor is
For each degree of centigrade temperature it outputs 10milli volts
ADC0808
The ADC0808, ADC0809 data acquisition component 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.
3.11.2 Key Specifications
Resolution 8 Bits
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Total Unadjusted Error 12 LSB and 1 LSB
Single Supply 5 VDC
Low Power 15 m
3.11.3 Features
Easy interface to all microprocessors
Operates ratio metrically or with 5 VDC or analog span adjusted voltage reference
No zero or full-scale adjust required
8-channel multiplexer with address logic
0V to 5V input range with single 5V power supply
Outputs meet TTL voltage level specifications
Standard hermetic or molded 28-pin DIP package
28-pin molded chip carrier package
ADC0808 equivalent to MM74C949
ADC0809 equivalent to MM74C949-1
3.11.4 BLOCK DIAGRAM OF LM35
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Fig3.11.4(a): block diagram LM35
3.11.5 PIN DISCRIPTION OF LM35 SENSOR
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FIG3.11.5 (a): Block and Pin Diagram of LM35
3.12 CONVERTER CHARACTERISTICS
3.12.1 The Converter
The heart of this single chip data acquisition system is its 8-bit analog-to-digital
converter. The converter is designed to give fast, accurate, and repeatable conversions over
a wide range of temperatures. The converter is partitioned into 3 major sections: the 256R
ladder network, the successive approximation register, and the comparator. The converters
digital outputs are positive true. The 256R ladder network approach (Figure 1) was chosen
over the conventional R/2R ladder because of its inherent monotonicity.
The A/D converters successive approximation register (SAR) is reset on the
positive edge of the start conversion (SC) pulse. The conversion is begun on the falling
edge of the start conversion pulse. A conversion in process will be interrupted by receipt of
a new start conversion pulse. Continuous conversion may be accomplished by tying the end
of conversion (EOC) output to the SC input. If used in this mode, an external start
conversion pulse should be applied after power up. End-of-conversion will go low between
0 and 8 clock pulses after the rising edge of start conversion. influence on the repeatability
of the device.
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I/O Pins
Table (4)
ADDRESS LINE A, B, C:The device contains 8-channels. A particular channel is selected
by using the address decoder line. The above table shows the input states for address lines
to select any channel.
Address Latch Enable ALE:The address is latched on the Low High transition of ALE.
START: The ADCs Successive Approximation Register (SAR) is reset on the positive
edge i.e. Low- High of the Start Conversion pulse.
Output Enable:Whenever data has to be read from the ADC, Output Enable pin has to
be pulled high thus enabling the TRI-STATE outputs, allowing data to be read from the
data pins D0-D7.
End of Conversion (EOC):This Pin becomes high when the conversion has ended,
so the controller comes to know that the data can now be read from the data pins.
Clock:External clock pulses are to be given to the ADC; this can be given either from
LM 555 in Astable mode or the controller can also be used to give the pulses.
3.12.2 ADC interface with the Microcontrollers
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Fig3.12.2 (a): ADC interface with the Microcontrollers
3.13 LIQUID CRYSTAL DIS PLAY
LCD stands forLiquid Crystal Display. LCD is finding wide spread use replacing LEDs
(seven segment LEDs or other multi segment LEDs) because of the following reasons:
1. The declining prices of LCDs.
2. The ability to display numbers, characters and graphics. This is in contrast to LEDs,
which are limited to numbers and a few characters.
3. Incorporation of a refreshing controller into the LCD,
4. Ease of programming for characters and graphics.
These components are specialized for being used with the microcontrollers, which
means that they cannot be activated by standard IC circuits. They are used for writing
different messages on a miniature LCD.
Fig3.13 (a): LCD display
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A model described here is for its low price and great possibilities most frequently
used in practice. It is based on the HD44780 microcontroller (Hitachi) and can display
messages in two lines with 16 characters each. It displays all alphabets, Greek letters,
punctuation marks, mathematical symbols etc. In addition, it is possible to display symbols
that user makes up on its own.
Automatic shifting message on display (shift left and right), appearance of the
pointer, backlight etc. are considered as useful characteristics.
3.13.1 Pins Functions
There are pins along one side of the small printed board used for connection to the
microcontroller. There are total of 14 pins marked with numbers. Their function is
described in the table below:
Function Pin Number Name Logic State Description
Ground 1 Vss - 0V
Power supply 2 Vdd - +5V
Contrast 3 Vee - 0 Vdd
Control of
operating4 RS
0
1
D0 D7 are interpreted as
commands
D0 D7 are interpreted as data
Control of
operating
4 RS0
1
D0 D7 are interpreted as
commands
D0 D7 are interpreted as data
5 R/W0
1
Write data (from controller to LCD)
Read data (from LCD to controller)
6 E
0
1
From 1 to 0
Access to LCD disabled
Normal operating
Data/commands are transferred to
LCD
Data / commands 7 D0 0/1 Bit 0 LSB
8 D1 0/1 Bit 1
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9 D2 0/1 Bit 2
10 D3 0/1 Bit 3
11 D4 0/1 Bit 4
12 D5 0/1 Bit 5
13 D6 0/1 Bit 6
14 D7 0/1 Bit 7 MSB
Table (8)
3.13.2 LCD screen
LCD screen consists of two lines with 16 characters each. Each character consists of
5x7 dot matrix. Contrast on display depends on the power supply voltage and whether
messages are displayed in one or two lines. For that reason, variable voltage 0-Vdd is
applied on pin marked as Vee. Trimmer potentiometer is usually used for that purpose.
Some versions of displays have built in backlight (blue or green diodes). When used during
operating, a resistor for current limitation should be used (like with any LE diode).
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Fig3.13.2 (a): LCD screen
3.13.3 LCD Basic Commands
All data transferred to LCD through outputs D0-D7 will be interpreted as
commands or as data, which depends on logic state on pin RS:
RS = 1 - Bits D0 - D7 are addresses of characters that should be displayed. Built in
processor addresses built in map of characters and displays corresponding symbols.
Displaying position is determined by DDRAM address. This address is either previously
defined or the address of previously transferred character is automatically incremented.
RS = 0 - Bits D0 - D7 are commands which determine display mode. List of commands
which LCD recognizes are given in the table below:
Command RS RW D7 D6 D5 D4 D3 D2 D1 D0Execution
Time
Clear display 0 0 0 0 0 0 0 0 0 1 1.64Ms
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Cursor home 0 0 0 0 0 0 0 0 1 x 1.64mS
Entry mode set 0 0 0 0 0 0 0 1 I/D S 40uS
Display on/off control 0 0 0 0 0 0 1 D U B 40uS
Cursor/Display Shift 0 0 0 0 0 1 D/C R/L x x 40uS
Function set 0 0 0 0 1 DL N F x x 40uS
Set CGRAM address 0 0 0 1 CGRAM address 40uS
Set DDRAM address 0 0 1 DDRAM address 40uS
Read BUSY flag (BF) 0 1 BF DDRAM address -
Write to CGRAM or DDRAM 1 0 D7 D6 D5 D4 D3 D2 D1 D0 40uS
Read from CGRAM or DDRAM 1 1 D7 D6 D5 D4 D3 D2 D1 D0 40uS
Table (9)
I/D 1 = Increment (by 1) R/L 1 = Shift right
0 = Decrement (by 1) 0 = Shift left
S 1 = Display shift on DL 1 = 8-bit interface
0 = Display shift off 0 = 4-bit interface
D 1 = Display on N 1 = Display in two lines
0 = Display off 0 = Display in one line
U 1 = Cursor on F 1 = Character format 5x10 dots
0 = Cursor off 0 = Character format 5x7 dot
B 1 = Cursor blink on D/C 1 = Display shift
0 = Cursor blink off 0 = Cursor shift
3.13.\4 LCD Initialization
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Once the power supply is turned on, LCD is automatically cleared. This process
lasts for approximately 15mS. After that, display is ready to operate. The mode of
operating is set by default. This means that:
1. Display is cleared
2. Mode
DL = 1 Communication through 8-bit interface
N = 0 Messages are displayed in one line
F = 0 Character font 5 x 8 dots
3. Display/Cursor on/off
D = 0 Display off
U = 0 Cursor off
B = 0 Cursor blink off
4. Character entry
ID = 1 Addresses on display are automatically incremented by 1
S = 0 Display shift off
Automatic reset is mainly performed without any problems. If for any reason power
supply voltage does not reach full value in the course of 10mS, display will start perform
completely unpredictably.
If voltage supply unit cannot meet this condition or if it is needed to provide
completely safe operating, the process of initialization by which a new reset enabling
display to operate normally must be applied.
Algorithm according to the initialization is being performed depends on whether
connection to the microcontroller is through 4- or 8-bit interface. All left over to be done
after that is to give basic commands and of course- to display messages.
3.13.5 LCD interface with the microcontroller (4-bit mode)
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Fig3.13.4 (a): LCD interface with the microcontroller (4-bit mode)
CHAPTER 4
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SOFTWARE IMPLEMENTATION OF THE PROJECT
DESIGN
This chapter briefly explains about the firmware implementation of the project. The
required software tools are discussed in section 4.2. Section 4.3 shows the flow diagram of
the project design. Section 4.4 presents the firmware implementation of the project design.
4.1 Software Tools Required
Keil v3, Proload are the two software tools used to program microcontroller. The
working of each software tool is explained below in detail.
4.1.1 Programming Microcontroller
Vision3
Vision3 is an IDE (Integrated Development Environment) that helps you write,
compile, and debug embedded programs. It encapsulates the following components:
A project manager.
A make facility.
Tool configuration.
Editor.
A powerful debugger.
To help you get started, several example programs (located in the \C51\Examples,
\C251\Examples, \C166\Examples, and \ARM\...\Examples) are provided.
HELLO is a simple program that prints the string "Hello World" using the Serial
Interface.
Building an Application in Vision2
To build (compile, assemble, and link) an application in Vision2, you must:
1. Select Project - (for example, 166\EXAMPLES\HELLO\HELLO.UV2).
2. Select Project - Rebuild all target files or Build target.
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Vision2 compiles, assembles, and links the files in your project.
Creating Your Own Application in Vision2
To create a new project in Vision2, you must:
1. Select Project - New Project.
2. Select a directory and enter the name of the project file.
3. Select Project - Select Device and select an 8052, 251, or C16x/ST10 device from
the Device Database.
4. Create source files to add to the project.
5. Select Project - Targets, Groups, Files, Add/Files, select Source Group1, and add
the source files to the project.
6. Select Project - Options and set the tool options. Note when you select the target
device from the Device Database all special options are set automatically. You
typically only need to configure the memory map of your target hardware. Default
memory model settings are optimal for most applications.
7. Select Project - Rebuild all target files or Build target.
Debugging an Application in Vision2
To debug an application created using Vision2, you must:
1. Select Debug - Start/Stop Debug Session.
2. Use the Step toolbar buttons to single-step through your program. You may enter
G, main in the Output Window to execute to the main C function.
3. Open the Serial Window using the Serial #1 button on the toolbar.
Debug your program using standard options like Step, Go, Break, and so on.
Starting Vision2 and creating a Project
Vision2 is a standard Windows application and started by clicking on the program
icon. To create a new project file select from the Vision2 menu
Project New Project. This opens a standard Windows dialog that asks you for the
new project file name.
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Building Projects and Creating a HEX Files
Typical, the tool settings under Options Target are all you need to start a new
application. You may translate all source files and line the application with a click on the
Build Target toolbar icon. When you build an application with syntax errors, Vision2 will
display errors and warning messages in the Output
Window Build page.
Database selection
You have made when you create your project target. Refer to page 58 for more
Information about selecting a device. You may select and display the on-chip peripheral
components using the Debug menu. You can also change the aspects of each peripheral
using the controls in the dialog boxes.
Start Debugging
You start the debug mode of Vision2 with the Debug Start/Stop Debug Session
command. Depending on the Options for Target Debug Configuration, Vision2 will
load the application program and run the startup code Vision2 saves the editor screen
layout and restores the screen layout of the last debug session.
Disassembly Window
The Disassembly window shows your target program as mixed source and
assembly program or just assembly code. A trace history of previously executed
instructions may be displayed with Debug View Trace Records. To enable the trace
history, set Debug Enable/Disable Trace Recording.
If you select the Disassembly Window as the active window all program step
commands work on CPU instruction level rather than program source lines. You can select
a text line and set or modify code breakpoints using toolbar buttons or the context menu
commands.
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4.2 SOURCE CODE:
1. Click on the Keil uVision Icon on Desktop
2. The following fig will appear.
3. Click on the Project menu from the title bar
4. Then Click on New Project
5. Save the Project by typing suitable project name with no extension in u r ownfolder sited in either C:\ or D:\
6. Then Click on save button above.
7. Select the component for u r project. i.e. Atmel
8. Click on the + Symbol beside of Atmel
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9. Select AT89C51
10. Then Click on OK
11. The Following fig will appear
12. Then Click either YES or NOmostly NO
13. Now your project is ready to USE
14. Now double click on the Target1, you would get another option Source group
1
15. Click on the file option from menu bar and select new
16. The next screen will be as shown in next page, and just maximize it by double
clicking on its blue boarder.
17. Now start writing program in either in C or ASM
18. For a program written in Assembly, then save it with extension . asm and for
C based program save it with extension .C
19. Now right click on Source group 1 and click on Add files to Group Source
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20. Now you will get another window, on which by default C files will appear.
21. Now select as per your file extension given while saving the file
22. Click only one time on option ADD
23. Now Press function key F7 to compile. Any error will appear if so happen.
24. If the file contains no error, then press Control+F5 simultaneously.
25. The new window is as follows
26. Then Click OK
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27. Now Click on the Peripherals from menu bar, and check your required port.
28. Drag the port a side and click in the program file.
29. Now keep Pressing function key F11 slowly and observe.
30. You are running your program successfully
4.3 PROLOAD
Proload is software which accepts only hex files. Once the machine code is
converted into hex code, that hex code has to be dumped into the microcontroller and this
is done by the Proload. Proload is a programmer which itself contains a microcontroller in
it other than the one which is to be programmed. This microcontroller has a program in it
written in such a way that it accepts the hex file from the Keil compiler and dumps this hexfile into the microcontroller which is to be programmed. As the Proload programmer kit
requires power supply to be operated, this power supply is given from the power supply
circuit designed above. It should be noted that this programmer kit contains a power supply
section in the board itself but in order to switch on that power supply,
Fig 4.3(a): Atmel 8052 compiler
4.4 Features
Supports major Atmel 89 series devices
Auto Identify connected hardware and devices
Error checking and verification in-built
Lock of programs in chip supported to prevent program copying
20 and 40 pin ZIF socket on-board
Auto Erase before writing and Auto Verify after writing
Informative status bar and access to latest programmed file
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Simple and Easy to use
Works on 57600 speed
4.5 Description
It is simple to use and low cost, yet powerful flash microcontroller programmer for
the Atmel 89 series. It will Program, Read and Verify Code Data, Write Lock Bits, Erase
and Blank Check. All fuse and lock bits are programmable. This programmer has
intelligent onboard firmware and connects to the serial port. It can be used with any type of
computer and requires no special hardware. All that is needed is a serial communication
ports which all computers have.
Fig 4.3(b): dumping of program
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CHAPTER 5
RESULTS
Assemble the circuit on the PCB as shown in Fig below. After assembling the
circuit on the PCB, check it for proper connections before switching on the power supply.
5.1 Transmitter kit
Fig (a): transmission kit
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The above fig shows the overall view of the kit. We have two sensors light
dependent resister and temperature sensor(LM35).The LM35 converts temp value into
electrical signal and LDRs senses intensity of light.555 Timer generates the pulse and
given to ADC which converts analog signal into digital signal and provides to
microcontroller.
We have the arc input available at the mains supply i.e., 230V is to be brought
down to the required voltage level. This is done by a step down transformer. The output
from the transformer is fed to the rectifier. It converts A.C. into pulsating D.C. The rectifier
may be a half wave or a full wave rectifier. Capacitive filter is used in this project. It
removes the ripples from the output of rectifier and smoothens the D.C. Output received
from this filter is constant until the mains voltage and load is maintained constant. Power
supply of 5V is required. In order to obtain the voltage level, 7805 voltage regulators is to
be used. The microcontroller has a CPU in addition to a fixed amount ofRAM, ROM, I/O
ports and a timer embedded all on a single chip. It controls the kit.
The microcontroller provides the converted digital values to HT640 RF Encoder.
STT-433 MHz RF transmitter transmits the digital values using transmitting antenna.
5.2 Receiver kit
Fig (b): reception kit
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These same values received at the STR-433 MHz Receiver and a HT648 RF
Decoder .this decoder converts signal bit data into 8.bit data and presents it to the
microcontroller. Now it is the job of the controller to read the data and display the same
data on LCD
5.3 Wireless weather monitoring kit
Fig(c): wireless weather monitoring kit
The working of wireless weather monitoring system kit is shown while it is in working. If
it exceeds the limit then buzzer will ON. If its not so then it will be in OFF condition and
LEDs continuously blinks.LCD also continuously shows the LDR and TEMP as shown in
above figure
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CHAPTER 6
CONCLUSIONThe implementation of weather monitoring system using RF is done successfully.
The communication is properly done without any interference between different modules
in the design. Design is done to meet all the specifications and requirements. Software tools
like Keil Uvision Simulator, Proload to dump the source code into the microcontroller,
Orcad Lite for the schematic diagram have been used to develop the software code before
realizing the hardware.
Circuit is implemented in Orcad and implemented on the microcontroller board.
The performance has been verified both in software simulator and hardware design. The
total circuit is completely verified functionally and is following the application software.
It can be concluded that the design implemented in the present work provide
portability, flexibility and the data transmission is also done with low power consumption
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CHAPTER 7
REFERENCES
1. Muhammad Ali Mazidi, Janice Gillispie Mazidi, and Rolin D.McKinla,The 8051 Microcontroller and Embedded Systems Using Assembly and C;
Pearson Education Inc.., 2006.
2. Kenneth J.Ayala , The 8051 Microcontroller Architecture, Programming, and
Application; West Publishing Company, USA.,1991
3. B.Ram, Computer Fundamentals Architecture and Organization; New Age
International (P) Ltd., Publishers, 2000.
4. Horn, and Delton T, Electronic Components A Complete Reference for Project
Builders; McGraw-Hill/Tab Electronics, 1991.
5. E Balagurusamy , Programming In ANSI C;Tata McGraw-Hill Publishing
Company Ltd,2008.
Websites
1. http://www.google.com
2. http://books.google.com
3. http://www.atmel.com
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4. http://www.datasheets4u.com
10. http://www.8051projects.net
http://www.datasheets4u.com/http://www.8051projects.net/http://www.datasheets4u.com/http://www.8051projects.net/