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Transcript of Obstacle Robot
OBSTACLE AVOIDING ROBOT
ABSTRACT
AIM:
The main objective of this project is to develop an embedded system, which will
automatically stop when an obstacle is detected using ultrasonic sensor.
IMPLEMENTATION:
This project is implemented 8051 based At89s52 developed board interfaced with
Ultrasonic sensor, H-Bridge driver motors.
BLOCK DIAGRAM:
POWER SUPPLY:
MICROCONTROLLER AT89S52
RPSL293D
INFRARED SENSOR
CRYSTAL ROBOTICPLATFORM
ULTRASONIC SENSOR
DESCRIPTION:
A robot can talk, walk, run and do anything as per logic embedded in it even
though the robot can do the above things. It seems a useless thing if it is uncontrollable.
Here controlling a robot is main task has to consider while designing any robot.
In this project an ultrasonic sensor is used to detect any obstruction and in turn
signals to the microcontroller and same displays on the LCD. An ultrasonic sensor is a
dual communication means transmitting and receiving. According to received data
vehicle will stop automatically.
Since robotic platform is equipped with two motors for the drive, controlling the
motors, i.e. When making a right turn, the right wheel can be stopped i.e. Power to the dc
motor is switched off. The left wheel is driven i.e. Left dc motor is on. This causes the
system to take a right turn. Similarly for left turn.
The detector circuitry consists of two ultrasonic integrated detection. The detector
houses the transmitter as well as receiver. The detectors are positioned accurately either
side. Once the detector recognizes any obstruction, the microcontroller signals the vehicle
to stop.
The system uses a compact circuitry built around flash version of at89s52
microcontroller with a non-volatile memory capable of retaining the password data for
over ten years. Programs are developed in embedded c using ride compiler. Isp is used to
dump the code into the microcontroller.
Step DownTransformer
BridgeRectifier
FilterCircuit Regulator
section
SOFTWARE:
Embedded ‘C’
RIDE to write code
ISP to burn the chip
HARDWARE:
At89s52 based our own developed board
Power Supply
Ultrasonic Sensor
H-Bridge driver motors
LCD
ADVANTAGES: Low cost, automated operation, Low Power consumption.
REFERENCES
1. The 8051 micro controller and embedded systems by Mazidi.
2. www.wikipedia.org
3. WWW.ATMEL.COM
4. WWW.8051PROJECTS.COM
5. Embedded systems with 8051 by kenith j ayala
OBSTACLE AVOIDING ROBOT
Chapter 1Embedded Systems1.1 INTRODUCTION TO EMBEDDED SYSTEMS
Each day, our lives become more dependent on 'embedded systems', digital
information technology that is embedded in our environment. More than 98% of
processors applied today are in embedded systems, and are no longer visible to the
customer as 'computers' in the ordinary sense. An Embedded System is a special-purpose
system in which the computer is completely encapsulated by or dedicated to the device or
system it controls. Unlike a general-purpose computer, such as a personal computer, an
embedded system performs one or a few pre-defined tasks, usually with very specific
requirements. Since the system is dedicated to specific tasks, design engineers can
optimize it, reducing the size and cost of the product. Embedded systems are often mass-
produced, benefiting from economies of scale. The increasing use of PC hardware is one
of the most important developments in high-end embedded systems in recent years.
Hardware costs of high-end systems have dropped dramatically as a result of this trend,
making feasible some projects which previously would not have been done because of
the high cost of non-PC-based embedded hardware. But software choices for the
embedded PC platform are not nearly as attractive as the hardware.
Typically, an embedded system is housed on a single microprocessor board with
the programs stored in ROM. Virtually all appliances that have a digital interface --
watches, microwaves, VCRs, cars -- utilize embedded systems. Some embedded systems
include an operating system, but many are so specialized that the entire logic can be
implemented as a single program.
Physically, Embedded Systems range from portable devices such as digital watches and
MP3 players, to large stationary installations like traffic lights, factory controllers, or the
systems controlling nuclear power plants.
In terms of complexity embedded systems can range from very simple with a single
microcontroller chip, to very complex with multiple units, peripherals and networks
mounted inside a large chassis or enclosure.
Definition of an Embedded System
Embedded system is defined as, For a particular/specific application
implementing the software code to interact directly with that particular hardware what we
built. Software is used for providing features and flexibility, Hardware = {Processors,
ASICs, Memory,...} is used for Performance (& sometimes security)
(or)
An embedded system is a special-purpose computer system designed to perform
one or a few dedicated functions, often with real-time computing constraints. It is usually
embedded as part of a complete device including hardware and mechanical parts. In
contrast, a general-purpose computer, such as a personal computer, can do many different
tasks depending on programming.
(or)
An embedded system is a single-purpose computer built into a larger system for the
purposes of controlling and monitoring the system. A specialized computer system that is
part of a larger system or machine.
There are many definitions of embedded system but all of these can be combined
into a single concept. An embedded system is a special purpose computer system that is
used for particular task.
Features of Embedded Systems
The versatility of the embedded computer system lends itself to utility in all kinds of
enterprises, from the simplification of deliverable products to a reduction in costs in their
development and manufacture. Complex systems with rich functionality employ special
operating systems that take into account major characteristics of embedded systems.
Embedded operating systems have minimized footprint and may follow real-time
operating system specifics.
The special computers system is usually less powerful than general-purpose systems,
although some expectations do exist where embedded systems are very powerful and
complicated. Usually a low power consumption CPU with a limited amount of memory is
used in embedded systems. Many embedded systems use very small operating systems;
most of these provide very limited operating system capabilities.
Since the embedded system is dedicated to specific tasks, design engineers can optimize
it, reducing the size and cost of the product, or increasing the reliability and performance.
Some embedded systems are mass-produced, benefiting from economies of scale.
Some embedded systems have to operate in extreme environment conditions such as very
high temperature & humidity.
For high volume systems such as portable music players or mobile phones, minimizing
cost is usually the primary design consideration. Engineers typically select hardware that
is just “good enough” to implement the necessary functions.
For low volume or prototype embedded systems, general purpose computers may be
adapted by limiting the programs or by replacing the operating system with a real-time
operating system.
Characteristics of Embedded Systems
Embedded computing systems generally exhibit rich functionality—complex
functionality is usually the reason for introducing CPUs into the design. However, they
also exhibit many non-functional requirements that make the task especially challenging:
• real-time deadlines that will cause system failure if not met;
• multi-rate operation;
• in many cases, low power consumption;
• low manufacturing cost, which often means limited code size.
Workstation programmers often concentrate on functionality. They may consider the
performance characteristics of a few computational kernels of their software, but rarely
analyze the total application. They almost never consider power consumption and
manufacturing cost. The need to juggle all these requirements makes embedded system
programming very challenging and is the reason why embedded system designers need to
understand computer architecture.
Overview of an Embedded System Architecture
Every Embedded system consists of a custom-built hardware built around a central
processing unit. This hardware also contains memory chips onto which the software is
loaded.
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
desktop computer. However these are significant differences. It is not compulsory to have
an operating system in every embedded system. For small applications such as remote
control units, air conditioners, toys etc.
Applications of Embedded Systems
APPLICATION SOFTWAREOPERATING SYSTEM
H/W
Some of the most common embedded systems used in everyday life are
Small embedded controllers: 8-bit CPUs dominate, simple or no operating system (e.g., thermostats)
Control systems: Often use DSP chip for control computations (e.g., automotive engine control)
Distributed embedded control: Mixture of large and small nodes on a real-time Embedded networks (e.g., cars, elevators, factory automation)System on chip: ASIC design tailored to application area
(e.g., consumer electronics, set-top boxes)Network equipment: Emphasis on data movement/packet flow
(e.g., network switches; telephone switches)Critical systems: Safety and mission critical computing
(e.g., pacemakers, automatic trains)Signal processing: Often use DSP chips for vision, audio, or other signal Processing (e.g., face recognition)Robotics: Uses various types of embedded computing (especially Vision and control) (e.g., autonomous vehicles)Computer peripherals: Disk drives, keyboards, laser printers, etc.Wireless systems: Wireless network-connected “sensor networks” and “Motes” to gather and report informationEmbedded PCs: Palmtop and small form factor PCs embedded into EquipmentCommand and control: Often huge military systems and “systems of systems” (e.g., a fleet of warships with interconnected Computers)
Home Appliances, intercom, telephones, security systems, garage door openers,
answering machines, fax machines, home computers, TVs, cable TV tuner, VCR,
camcorder, remote controls, video games, cellular phones, musical instruments, sewing
machines, lighting control, paging, camera, pinball machines, toys, exercise equipment
Office Telephones, computers, security systems, fax machines, microwave, copier, laser
printer, color printer, paging
Auto Trip computer, engine control, air bag, ABS, instrumentation, security system,
transmission control, entertainment, climate control, cellular phone, keyless entry
TYPES OF EMBEDDED SYSTEMS
Based on functionality and performance embedded systems categorized as 4 types
1. Stand alone embedded systems
2. Real time embedded systems
3. Networked information appliances
4. Mobile devices
1. Stand alone embedded systems:-
As the name implies, stand alone systems work in stand alone mode. They take i/p,
process them and produce the desire o/p. The i/p can be an electrical signal from
transducer or temperature signal or commands from human being. The o/p can be
electrical signal to drive another system an led or lcd display
ex digital camera, microwave oven, CD player, Air conditioner etc
2. Real time embedded systems:-
In this type of an embedded system a specific work has to be complete in a particular period of time.
Hard Real time systems:- embedded real time used in missiles
Soft Real time systems:- DVD players
3. Networked information appliances:-
Embedded systems that are provided with n/w interfaces and accessed by n/w's such as
local area n/w or internet are called Network Information Appliances
Ex A web camera is connected to the internet. Camera can send pictures in real time to
any computers connected to the internet
4. Mobile devices:-
Actually it is a combination of both VLSI and Embedded System
Mobile devices such as Mobile phone, Personal digital assistants, smart phones etc are
special category of embedded systems
2.2 Introduction to Microcontroller
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 go for these
3. DSP ( Digital Signal Processor ):- are for high and sensitive application purpose
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, they have the advantage of versatility such that the
designer can decide on the amount of RAM, ROM and I/O ports needed to fit the task at
hand.
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. 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.
CPU platform:
Embedded processors can be broken into two distinct categories: microprocessors (μP)
and microcontrollers (μC). Microcontrollers have built-in peripherals on the chip,
reducing size of the system.
There are many different CPU architectures used in embedded designs such as ARM,
MIPS, Coldfire/68k, PowerPC, x86, PIC, 8051, Atmel AVR, Renesas H8, SH, V850,
FR-V, M32R, Z80, Z8, etc. This in contrast to the desktop computer market, which is
currently limited to just a few competing architectures.
PC/104 and PC/104+ are a typical base for small, low-volume embedded and ruggedized
system design. These often use DOS, Linux, NetBSD, or an embedded real-time
operating system such as QNX or VxWorks.
A common configuration for very-high-volume embedded systems is the system on a
chip (SoC), an application-specific integrated circuit (ASIC), for which the CPU core was
purchased and added as part of the chip design. A related scheme is to use a field-
programmable gate array (FPGA), and program it with all the logic, including the CPU.
Embedded systems are based on the concept of the microcontroller, a single integrated
circuit that contains all the technology required to run an application. Microcontrollers
make integrated systems possible by combining several features together into what is
effectively a complete computer on a chip, including:
* Central Processing Unit
* Input/Output interfaces (such as serial ports)
* Peripherals (such as timers)
* ROM, EEPROM or Flash memory for program storage
* RAM for data storage
* Clock generator
By integrating all of these features into a single chip it is possible to greatly reduce the
number of chips and wiring necessary to control an electronic device, dramatically
reducing its complexity, size and cost.
* Size & Weight: Microcontrollers are designed to deliver maximum performance for
minimum size and weight. A centralized on-board computer system would greatly
outweigh a collection of microcontrollers.
* Efficiency: Microcontrollers are designed to perform repeated functions for long
periods of time without failing or requiring service.
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
INTRODUCTION TO 8051
Intel Corporation introduced an 8 bit micro controller called the 8051 in 1981. While the
time of introduction, Intel was given some specific features and particular name as
MCS-51
Features:-
ROM ---- 4 K bytes of Memory
RAM ----- 128 bytes
Timers------2
4 ports --- 32 I/O ports ( each 8 bit wide )
Interrupts-----6
serial port-----1
all on a single chip
Many semiconductor manufacturers started either manufacturing the 8051 devices as
such (Intel was liberal in giving away license to whoever asked) or developing a new
kind of microcontrollers based on 8051 core architecture. Manufacturers modified the
basic 8051 architecture and added many new peripheral functions to make them attractive
to the designers.
After that so many industries are come into picture to introduce 8051 again wit some
extra features. This has led to many versions of the 8051 with different speeds and
amounts of on-chip ROM marketed by more manufactures those are
Dallas ------ DS4700
Zilog---------Z
Motrolla
Freescale
Atmel ------- AT89C51/52, AT89S51/52
Phillips ----- P89C51RD2Fn
Before these industries came into picture 8051 chips are made with CMOs technology.
ATmel was introduced with ISP (In System Programming)
In System Programming (ISP):-
In-System Programming (ISP) is the ability of some PROGRAMMABLE LOGIC
DEVICES, MICROCONTROLLERS, and other programmable electronic chips to be
programmed while installed in a complete system, rather than requiring the chip to be
programmed prior to installing it into the system. (or) In-system programming is a
valuable feature that allows system firmware to be upgraded without disassembling the
embedded system to physically replace memory. Most Maxim 8051-based
microcontrollers can be reprogrammed from a PC or laptop via an inexpensive RS-232
serial interface and a few logic gates
The primary advantage of this feature is that it allows manufacturers of electronic devices
to integrate programming and testing into a single production phase, rather than requiring
a separate programming stage prior to assembling the system. This may allow
manufacturers to program the chips in their own system's production line instead of
buying preprogrammed chips from a manufacturer or distributor, making it feasible to
apply code or design changes in the middle of a production run.
2.3 AT89S52 MICROCONTROLLER
The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K
bytes of in-system programmable Flash memory. The device is manufactured using
Atmel’s high-density nonvolatile memory technology and is compatible with the
industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the
program memory to be reprogrammed in-system or by a conventional nonvolatile
memory programmer. By combining a versatile 8-bit CPU with in-system programmable
Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which
provides a highly-flexible and cost-effective solution to many embedded control
applications.
8051 PIN DIAGRAM
AT89S52 Architecture consists of these specific features:
8 bit CPU with registers A (Accumulator) and B
16 bit Program Counter(PC) and Data Pointer (DPTR)
8 bit Program Status Word (PSW)
8 bit Stack Pointer (SP)
Internal ROM of 8k
Internal RAM of 128 bytes
Four Register banks each containing eight registers
Sixteen bytes, which may be addressed at the bit level
Eighty bytes of general purpose data memory
32 I/O pins arranged as four 8-bit ports: P0,P1,P2,P3
Two 16-bit Timers/Counters: T0 and T1
Full duplex serial data Receiver/Transmitter : SBUF
Control Registers: TCON, TMOD, SCON, SMOD, PCON, IP and IE.
Two external and three internal interrupt sources.
Oscillator and Clock circuits.
Pin Description
Pin ( 32 – 39 ) Port 0: Port 0 is an 8-bit open drain bidirectional port. As an open drain
output port, it can sink eight LS TTL loads. Port 0 pins that have 1s written to them float,
and in that state will function as high impedance inputs. Port 0 is also the multiplexed
low-order address and data bus during accesses to external memory. In this application it
uses strong internal pull ups when emitting 1s. Port 0 emits code bytes during program
verification. In this application, external pull ups are required.
Pin ( 1- 8 ) Port 1: Port 1 is an 8-bit bidirectional I/O port with internal pull ups. Port 1
pins that have 1s written to them are pulled high by the internal pull ups, and in that state
can be used as inputs. As inputs, port 1 pins that are externally being pulled low will
source current because of the internal pull ups.
Alternate Functions of Port 1 used for In system Programmable
P.5 MOSI --------- Instruction Input
P.6 MISO ---------- Data Output
P.7 SCK ----------- Clk in
Pin ( 21 – 28 ) Port 2: Port 2 is an 8-bit bidirectional I/O port with internal pull ups.
Port 2 emits the high-order address byte during accesses to external memory that use 16-
bit addresses. In this application, it uses the strong internal pull ups when emitting 1s.
Pin (10 – 17) Port 3: Port 3 is an 8-bit bidirectional I/O port with internal pull ups. It
also serves the functions of various special features of the 80C51 Family as follows:
Port Pin Alternate Function
P3.0- RxD (serial input port)
P3.1 -TxD (serial output port)
P3.2 -INT0 (external interrupt 0)
P3.3- INT1 (external interrupt 1)
P3.4 -T0 (timer 0 external input)
P3.5 -T1 (timer 1 external input)
P3.6 -WR (external data memory write strobe)
P3.7 -RD (external data memory read strobe)
Pin 40 VCC: -Supply voltage
Pin 20 VSS: -Circuit ground potential
Pin 29 PSEN: Program Store Enable is the read strobe to external Program Memory.
When the device is executing out of external Program Memory, PSEN is activated twice
each machine cycle (except that two PSEN activations are skipped during accesses to
external Data Memory). PSEN is not activated when the device is executing out of
internal Program Memory.
Pin 30 ALE/PROG: Address Latch Enable output pulse for latching the low byte of the
address during accesses to external memory. ALE is emitted at a constant rate of 1/6 of
the oscillator frequency, for external timing or clocking purposes, even when there are no
accesses to external memory. (However, one ALE pulse is skipped during each access to
external Data Memory.) This pin is also the program pulse input (PROG) during EPROM
programming.
Pin 31 EA/VPP: When EA is held high the CPU executes out of internal Program
Memory. Holding EA low forces the CPU to execute out of external memory regardless
of the Program Counter value. In the 80C31, EA must be externally wired low. In the
EPROM devices, this pin also receives the programming supply voltage (VPP) during
EPROM programming.
Pin 18 XTAL1: Input to the inverting oscillator amplifier.
Pin 19 XTAL2: Output from the inverting oscillator amplifier.
REGISTERS
8051 is a collection of 8 and 16 bit registers and 8 bit memory locations. These registers
and memory locations can be made to operate using the software instructions. The
program instructions control the registers and digital data paths that are contained inside
the 8051, as well as memory locations that are located outside the 8051.
Register are used to store information temporarily, while the information could be a byte
of data to be processed, or an address pointing to the data to be fetched. The vast majority
of 8051 register are 8-bit registers.
Generally there are two types of registers. They are General purpose Registers (GPR’s)
and Special Function Registers (SFR’s)
General Purpose Register
The 8 bits of a register are shown from MSB D7 to the LSB D0. With an 8-bit data type, any data larger than 8 bits must be broken into 8-bit chunks before it is processed.
The most widely used registers A (Accumulator) For all arithmetic and logic instructions B, R0, R1, R2, R3, R4, R5, R6, R7 DPTR (data pointer), and PC (program counter)
16 – bit General Purpose Register are Data Pointer (DPTR) and Program Counter (PC)
The program counter points to the address of the next instruction to be executed. DPTR.
As the name suggests, is used to point the data. It is used by a number of commands
which allows the microcontroller to access external memory. When the microcontroller
access external memory it will access at the address indicated by DPTR.
There are 128 bytes of RAM in the 8051
The 128 bytes are divided into three different groups as follows:
1) A total of 32 bytes from locations 00 to 1F hex are set aside for register banks and the
stack
2) A total of 16 bytes from locations 20H to 2FH are set aside for bit-addressable
read/write memory
3) A total of 80 bytes from locations 30H to 7FH are used for read and write storage,
called scratch pad
Special Function Registers
The program status word (PSW)PSW register, also referred to as the flag register, is an 8 bit register Only 6 bits are used
These four are CY (carry), AC (auxiliary carry), P (parity), and OV (overflow)
They are called conditional flags, meaning that they indicate some conditions that
resulted after an instruction was executed. The PSW3 and PSW4 are designed as RS0 and
RS1, and are used to change the bank. The two unused bits are user-definable
–
2.4 Timer/Counters
The Atmel 80C51 Microcontrollers implement two general purpose, 16-bit timers/
counters. They can be used either as timers to generate a time delay or as a counter to
count events happening outside the microcontroller. The microcontroller has two 16-bit
wide timers. They are identified as Timer 0 and Timer 1, 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, then issues
an interrupt request. When operating as a counter, the timer/counter counts negative
transitions on an external pin. After a preset number of counts, the counter issues an
interrupt request. Register pairs (TH0, TL0), (TH1, TL1), and (TH2, TL2) are the 16-bit
counting registers for Timer/Counters 0, 1, and 2, respectively.
Timer 0 Register
The 16-bit register of Timer 0 is accessed as low byte and high byte. The low byte
register is called TL0 (Timer 0 low byte) and high byte register is referred to as TH0
(Timer 0 high byte). These registers can be accessed like any other register, such as
A,B,R0,R1,R2,etc.
Timer 1 Register
Timer 1 is also 16-bits, and its 16-bit register is split into two bytes, referred to as TL1
( Timer 1 low byte ) and TH1 ( Timer 1 high byte ). These registers are accessible in the
same way as the registers of timer 0.
TMOD Register (timer mode)
TMOD: Timer/Counter Mode Control Register.
Not Bit Addressable.
Timer 1 Timer 0
GATE When TRx (in TCON) is set and GATE=1, Timer/CounterX will
run only while INTx pin is high (hardware control). When
GATE=0, Timer/Counter will run only while TRx=1 (software
control).
C/T Timer or Counter selector. Cleared for Timer operation (input from
internal system clock). Set for Counter operation (input from TX
input pin).
M1 Mode selector bit.
M0 Mode selector bit.
M1 M0 Mode Operating Mode
0 0 0 13-bit Timer (8048 compatible) (TH1)
0 1 1 16-bit Timer/Counter
1 0 2 8-bit Auto-Reload Timer/Counter (TL1). Reloaded from TH1 at overflow.
1 1 3 timer 1 halted. Retains count.
1 1 3 (Timer 1) Timer/Counter 1 stopped.
TCON: Timer/Counter Control Register
Bit Addressable.
TF1 Timer1 overflow flag. Set by hardware when the Timer/Counter 1
overflows. Cleared by hardware as processor vectors to the interrupt
service routine.
TR1 Timer 1 run control bit. Set/cleared by software to turn Timer/Counter 1
ON/OFF.
TF0 Timer0 overflow flag. Set by hardware when the Timer/Counter 0
overflows. Cleared by hardware as processor vectors to the service
routine.
THE LOWER 4 BITS
THE UPPER FOUR BITS ARE USED TO
TR0 Timer 0 run control bit. Set/cleared by software to turn Timer/Counter 0
ON/OFF.
IE1 External Interrupt 1 edge flag. Set by hardware when External terrupt
edge is detected. Cleared by hardware when interrupt is processed.
IT1 Interrupt 1 type control bit. Set/cleared by software to specify falling
edge/low level triggered External Interrupt.
IE0 External Interrupt 0 edge flag. Set by hardware when External Interrupt
edge is detected. Cleared by hardware when interrupt is processed.
IT0 Interrupt 0-type control bit. Set/cleared by software to specify falling
edge/low level triggered External Interrupt.
2.5 SERIAL COMMUNICATION
The 8051 serial port is full duplex. In other words, it can transmit and receive data at the
same time. Unlike any other register in the 8051, SBUF is in fact two distinct registers - the
write-only register and the read-only register. Transmitted data is sent out from the write-
only register while received data is stored in the read-only register. There are two separate
data lines, one for transmission (TXD) and one for reception (RXD). Therefore, the serial
port can be transmitting data down the TXD line while it is at the same time receiving data
on the RXD line. The TXD line is pin 11 of the microcontroller (P3.1) while the RXD line
is on pin 10 (P3.0)
Serial data communication uses two methods, asynchronous and synchronous. The
synchronous method transfers a block of data (characters) at a time, while the asynchronous
method transfers a single byte at a time. It is possible to write software to use either of these
methods, but the programs can be tedious and long. For this reason, there are special IC chips
made by many manufacturers for serial data communications. These chips can be commonly
referred to as UART (Universal Asynchronous Receiver-transmitter) and USART
( Universal Synchronous Asynchronous Receiver-Transmitter). The 8051 chip has a built-in
UART.
Asynchronous Serial Communication and Data Framing
Start Bits and Stop Bits
In the asynchronous method is character is placed between start and stop bits, this is called
data framing. In asynchronous communication, at least two extra bits are transmitted with the
data word; a start bit and a stop bit. Therefore, if the transmitter is using an 8-bit system, the
actual number of bits transmitted per word is ten. In most protocols the start bit is a logic 0
while the stop bit is logic 1. Therefore, when no data is being sent the data line is
continuously HIGH. The receiver waits for a 1 to 0 transition. In other words, it awaits a
transition from the stop bit (no data) to the start bit (logic 0). Once this transition occurs the
receiver knows a data byte will follow. Since it knows the data rate (because it is defined in
the protocol) it uses the same clock as frequency as that used by the transmitter and reads the
correct number of bits and stores them in a register. For example, if the protocol determines
the word size as eight bits, once the receiver sees a start bit it reads the next eight bits and
places them in a buffer. Once the data word has been read the receiver checks to see if the
next bit is a stop bit, signifying the end of the data. If the next bit is not a logic 1 then
something went wrong with the transmission and the receiver dumps the data. If the stop bit
was received the receiver waits for the next data word, ie; it waits for a 1 to 0 transition.
Baud Rates in the 8051
GOES OUT FIRST
XTAL OSCILLATOR
÷ 12 ÷ 32BY UART
MACHINE CYCLE FREQUENCY
28800 HZ
TO TIMER 1 TO SET THE BAUD RATE
921.6 KHZ
11.0592 MHZ
TIMER 1
XTAL = 11.0592 MHz:
The frequency of system clock = 11.0592 MHz / 12 = 921.6 kHz
The frequency sent to timer 1 = 921.6 kHz/ 32 = 28,800 Hz
(a) 28,800 / 3 = 9600 where -3 = FD (hex) is loaded into TH1
(b) 28,800 / 12 = 2400 where -12 = F4 (hex) is loaded into TH1
(c) 28,800 / 24 = 1200 where -24 = E8 (hex) is loaded into TH1
SBUF
SBUF is an 8-bit register used solely for serial communication in the 8051. For a byte of
data to be transferred via the TxD line, it must be placed in the SBUF register. Similarly,
SBUF holds the byte of data when it is received by the 8051’s RxD line. SBUF can be
accessed like any other register in the 8051.
The moment a byte is written into SBUF, it is framed with the start and stop bits and
transferred serially via the TxD pin. Similarly, when the bits are received serially via
RxD, the 8051 deframes it by eliminating the stop and start bits, making a byte out of the
data received, and then placing it in the SBUF.
DATA TRANSMISSION: -
Transmission of serial data bits begins anytime data is written to sbuf. " TI "
(SCON) set to 1 when data has been transmitted and signifies that " SBUF " is empty and
that another data byte can be sent.
DATA RECEPTION: -
Reception of serial data will begin if the receive enable bit (REN) in SCON is set
to ' 1 ' for all modes. For mode ' 0 ' only RI must be cleared to 0. Receiver interrupt flag '
RI ' (in SCON) is set after data has been received in all modes. Setting of ' REN ' bit is a
direct program control that limits the reception of unexpected data.
SCON ( Serial Control ) Register
SM0 SM1 SM2 REN TB8 RB8 TI RI
Mode 0: Serial data enters and exits through RxD. TxD outputs the shift clock. 8 bits are transmitted/received (LSB first). The baud rate is fixed at 1/12 the oscillator frequency.
Mode 1: 10 bits are transmitted (through TxD) or received (through RxD): a start bit (0),
8 data bits (LSB first), and a stop bit (1). On receive, the stop bit goes into RB8 in Special
Function Register SCON. The baud rate is variable.
Mode 2: 11 bits are transmitted (through TxD) or received (through RxD): start bit (0), 8
data bits (LSB first), a programmable 9th data bit, and a stop bit (1). On Transmit, the 9th
data bit (TB8 in SCON) can be assigned the value of 0 or 1. Or, for example, the parity
bit (P, in the PSW) could be moved into TB8. On receive, the 9th data bit goes into RB8
in Special Function Register SCON, while the stop bit is ignored. The baud rate is
programmable to either 1/32 or 1/64 the oscillator frequency.
Mode 3: 11 bits are transmitted (through TxD) or received (through RxD): a start bit (0),
8 data bits (LSB first), a programmable 9th data bit, and a stop bit (1). In fact, Mode 3 is
the same as Mode 2 in all respects except baud rate. The baud rate in Mode 3 is variable.
In all four modes, transmission is initiated by any instruction that uses SBUF as a
destination register. Reception is initiated in Mode 0 by the condition RI = 0 and REN =
1. Reception is initiated in the other modes by the incoming start bit if REN = 1.
SM2 Enables the multiprocessor communication feature in Modes 2 and 3. In Mode 2 or
3, if SM2 is set to 1, then Rl will not be activated if the received 9th data bit (RB8) is 0.
In Mode 1, if SM2=1 then RI will not be activated if a valid stop bit was not received. In
Mode 0, SM2 should be 0.
REN Enables serial reception. Set by software to enable reception. Clear by software to
disable reception.
TB8 The 9th data bit that will be transmitted in Modes 2 and 3. Set or clear by software
as desired.
RB8 In Modes 2 and 3, is the 9th data bit that was received. In Mode 1, it SM2=0, RB8 is
the stop bit that was received. In Mode 0, RB8 is not used.
TI (Transmit Interrupt)
This is an extremely important flag bit in the SCON register. When the 8051 finishes the
transfer of the 8-bit character it raises the TI flag to indicate that it is ready to transfer
another byte. The TI bit is raised at the beginning of the stop bit.
RI ( Receive Interrupt)
This is an extremely important flag bit in the SCON register. When the 8051 receives
data serially via RxD, it gets rid of the start and stop bits and places the byte in the SBUF
register. Then it raises the RI flag bit to indicate that a byte has been received and chould
be picked up before it is lost.
INTERRUPTS
An interrupt is a special feature which allows the 8051 to provide the illusion of "multi-
tasking," although in reality the 8051 is only doing one thing at a time. The word
"interrupt" can often be substituted with the word "event."
An interrupt is triggered whenever a corresponding event occurs. When the event occurs,
the 8051 temporarily puts "on hold" the normal execution of the program and executes a
special section of code referred to as an interrupt handler. The interrupt handler performs
whatever special functions are required to handle the event and then returns control to the
8051 at which point program execution continues as if it had never been interrupted.
Interrupt Service Routine
For every interrupt, there must be an interrupt service routine (ISR). Or interrupt handler.
When an interrupt is invoked, the microcontroller runs the interrupt service routine. For
every interrupt, there is a fixed location in memory that holds the address of its ISR. The
group of memory locations set aside to hold the addresses of the ISRs is called interrupt
vector table.
Six Interrupts in 8051
1. Reset : When the reset pin is activated, the 8051 jumps to address location 00002. Two interrupts are set aside for the timers: one for the Timer 0 and one for
Timer1.
3. Two interrupts are set aside for hardware external interrupts : one for INT0 and one for INT1
4. Serial communication has a single interrupt that belongs to both receive and transmit.
Enabling Interrupt (IE) Register
All interrupt are disabled after reset
We can enable and disable them bye IE
EA -- ET2 ES ET1 EX1 ET0 EX0
EA IE.7 If EA=0, disables all interrupts, no interrupt is acknowledged
If EA=1, each interrupt source is individually enabled or disabled by setting or clearing its enable bit.
-- IE.6 Not implemented, reserved for future use.
ET2 IE.5 Enables or disables Timer2 overflow or capture interrupt
(8052 only)
ES IE.4 Enables or disables the serial port interrupt.
ET1 IE.3 Enables or disables Timer 1 overflow interrupt.
EX1 IE.2 Enables or disables external interrupt 1.
ET0 IE.1 Enables or disables Timer 0 overflow interrupt.
EX0 IE.0 Enables or disables external interrupt 0.
Interrupt Priority (IP) Register
0= lower priority, 1= higher priority, reset IP=00H
Lower priority ISR can be interrupted by a high priority interrupt.
A high priority ISR can not be interrupted.
Low-priority interrupt wait until 8051 has finished servicing the high-priority interrupt.
-- -- PT2 PS PT1 PX1 PT0 PX0
-- IP.7 Reserved
-- IP.6 Reserved
PT2 IP.5 Timer2 interrupt priority bit (8052 only)
PS IP.4 serial port interrupt priority bit.
PT1 IP.3 Timer 1 interrupt priority bit.
PX1 IP.2 external interrupt 1 priority bit.
PT0 IP.1 Timer 0 interrupt priority bit.
PX0 IP.0 external interrupt 0 priority bit.
BASIC REQUIRMENT
The following are the basic five requirements of microcontroller
1. Power Supply
2. Crystal Oscillator
3. Reset
4. SIP Resistor
5. Resistor for EA Pin
1. Regulated Power Supply
In mains-supplied electronic systems the AC input voltage must be converted into a DC
voltage with the right value and degree of stabilization. The common DC voltages that
are required to power up the devices are generally in the range of 3 VDC to 30 VDC.
Typically the fixed types of DC voltages are 5V, 9V, 12V, 15V and 18V DC.
POWER SUPPLY MODULES:
STEP DOWN TRANSFORMER
BRIDGE RECTIFIER WITH FILTER
VOLTAGE REGULATORS
Transformer
Transformers convert AC electricity from one voltage to another with little loss of power.
Transformers work only with AC and this is one of the reasons why mains electricity is
AC. Step-up transformers increase voltage, step-down transformers reduce voltage.
A step down power transformer is used to step down the AC voltage from the LINE
VOLTAGE
of 110 VAC or 220 VAC i.e, it converts higher voltage at the input side to a lower voltage at the output.
Rectifier
There are several ways of connecting diodes to make a rectifier to convert AC to DC. The
BRIDGE RECTIFIER is the most important and it produces full-wave varying DC
Bridge rectifier Output: full-wave varying DC
Alternate pairs of diodes conduct, changing over (using all the AC wave)
the connections so the alternating directions of
AC are converted to the one direction of DC.
Filter
Filtering is performed by a large value electrolytic capacitor connected across the DC
supply to act as a reservoir, supplying current to the output when the varying DC voltage
from the rectifier is falling. The diagram shows the unfiltered varying DC (dotted line)
and the filtered DC (solid line). The capacitor charges quickly near the peak of the
varying DC, and then discharges as it supplies current to the output.
Typically 1000 μf capacitor is used
Regulator
This is a simple DC regulated supply project using 7805 voltage regulator to obtain a
variable DC voltage range from 5V to 15V
Pin out of the 7805 regulator IC.
1. Unregulated voltage in
2. Ground
3. Regulated voltage out
If you need other voltages than +5V, you can modify the circuit by replacing the 7805
chips with another regulator with different output voltage from regulator 78xx chip
family. The last numbers in the the chip code tells the output voltage. Remember that the
input voltage must be at least 3V greater than regulator output voltage ot otherwise the
regulator does not work well.
Crystal Oscillator
The 8051 uses the crystal for precisely that: to synchronize it’s 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 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).
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.
SIP Resistor
Sip Resistor is a single in pack Resistor (i.e.,) 8 resistors connected in series. Basically
SIP resistor is a 9 pin connector first pin is for power supply to the entire 8 resistors in
SIP.
Generally SIP Resistor is used to close the open drain connections of Port 0.
BLOCK DIAGRAM:
POWER SUPPLY:
Step DownTransformer
BridgeRectifier
FilterCircuit Regulator
section
MICROCONTROLLER AT89S52
RPSL293D
INFRAREDSENSOR
CRYSTAL ROBOTICPLATFORM
DESCRIPTION:
A robot can talk, walk, run and do anything as per logic embedded in it even
though the robot can do the above things. It seems a useless thing if it is uncontrollable.
Here controlling a robot is main task has to consider while designing any robot.
In this project an ultrasonic sensor is used to detect any obstruction and in turn
signals to the microcontroller and same displays on the LCD. An ultrasonic sensor is a
dual communication means transmitting and receiving. According to received data
vehicle will stop automatically.
Since robotic platform is equipped with two motors for the drive, controlling the
motors, i.e. When making a right turn, the right wheel can be stopped i.e. Power to the dc
motor is switched off. The left wheel is driven i.e. Left dc motor is on. This causes the
system to take a right turn. Similarly for left turn.
The detector circuitry consists of two ultrasonic integrated detection. The detector
houses the transmitter as well as receiver. The detectors are positioned accurately either
side. Once the detector recognizes any obstruction, the microcontroller signals the vehicle
to stop.
The system uses a compact circuitry built around flash version of at89s52
microcontroller with a non-volatile memory capable of retaining the password data for
over ten years. Programs are developed in embedded c using ride compiler. Isp is used to
dump the code into the microcontroller.
INFRARED SENSOR
As the infrared sensor device, PZT(Lead[Pb:Plumbum] Zirconate Titanate) is used. This
material has the nature that the electric charge in the surface is divided into the positive
electric charge and the negative electric charge in the usual condition.(Spontaneous
polarization)
The distribution of the electric charge is disordered when the infrared rays lash this
material and the voltage occurs. The infrared sensor outputs the change of this voltage.
The infrared sensor has the kinds such as the single type, the dual type, the quad type.
The dual type is often used to detect the move of the person, vehicle or the animal.
The two identical shape elements are used
for the dual-type sensor. And, it is put for
the pole of the element to become
opposite. When the change of the infrared
quantity occurs, being simultaneous with
the element which was put in this way,
because the occurring voltage is opposite,
it denies each other and the voltage doesn't appear in the output. The output voltage
changes only when there is a difference in the quantity of the infrared rays which enter
both elements. Because the same change occurs to both elements even if the infrared
quantity of the background in the place to detect with the sensor changes, little change of
the output occurs even if it occurs. When the person or the animal crosses the sensor, the
quantity of the infrared rays which enter both elements becomes not equal and the change
of the voltage appears in the output.
The body of the human being or the animal is emitting the infrared rays. This circuit is the
circuit to detect the change of the infrared rays by the infrared sensor and to work the
relay. Because the Fresnel lens is put to the infrared sensor, the move of the person in the
very narrow range can be detected. The important part is the pyroelectric infrared sensor. I
used the pyroelectric infrared sensor(RE814S) which is made by the NIPPON CERAMIC
company.
AT THIS DETECTION EQUIPMENT, FOLLOWING DEVICE
IS DONE TO MAKE DETECT ONLY THE MOVE OF THE
PERSON OR THE ANIMAL AS MUCH AS POSSIBLE.
It uses the dual element type as the infrared sensor and it makes to detect the change
of the infrared rays in the background little.
It makes the object place to detect using the Fresnel lens narrow.
It is using the band pass filter for the amplifier and it makes to detect the change
which was slowly or the too quick change little.
It uses the window comparator and the movement where little change occurs makes
not detect.
IR LED
A new range of broadband IR LEDs is now distributed by Scitec Instruments.
Typical emission bandwidth is 0.5 mm and power levels at 10s to 100s of microwatts
depending on duty cycle etc.
An electroluminescent IR LED is a product which requires care in use. IR LEDs are
fabricated from narrow band heterostructures with energy gap from 0.25 to 0.4 eV.
That's why the bias used to initiate current flow is low compared to the well known
visible or NIR LEDs. Typical forward bias is V~0.1- 1 V only for mid-IR LEDs!
Applications Remote Control Night Vision Traffic Automotive Lighting Switch Home Lighting Switch
Features Infrared with Large angle Low Power Consumption Longer Life Time I.C. Compatible
Typical Electrical & Optical Characteristics (Ta=25 Deg. C) DC forward voltage : VF (IF =20mA) 1.2V-1.4 Typ, 1.6VMax DC reverse current : IR (VR =5V) 100uA Power Output(Po) : Iv (IF =20mA) BI01 : 15 +/- 10mW Wavelength : Iv (IF =20mA) 940nm Outer Dimension: 5mm
MOTOR
Whenever a motorics hobbyist talk about making a motor, the first thing
comes to his mind is making the motor move on the ground. And there are
always two options in front of the designer whether to use a DC motor or a
stepper motor. When it comes to speed, weight, size, cost... DC motors are
always preffered over stepper motors. There are many things which you can
do with your DC motor when interfaced with a microcontroller. For example
you can control the speed of motor, you can control the direction of rotation,
you can also do encoding of the rotation made by DC motor i.e. keeping
track of how many turns are made by your motors etc. So you can see DC
motors are no less than a stepper motor.
In this part of project we will learn to interfacing a DC motor with a
microcontroller. Usually H-bridge is preffered way of interfacing a DC
motor. These days many IC manufacturers have H-bridge motor drivers
available in the market like L293D is most used H-Bridge driver IC. H-
bridge can also be made with the help of trasistors and MOSFETs etc. rather
of being cheap, they only increase the size of the design board, which is
somtimes not required so using a small 16 pin IC is preffered for this
purpose.
Working Theory of H-Bridge
The name "H-Bridge" is derived from the actual shape of the switching
circuit which control the motoion of the motor. It is also known as "Full
Bridge". Basically there are four switching elements in the H-Bridge as
shown in the figure below.
As you can see in the figure above there are four switching elements named
as "High side left", "High side right", "Low side right", "Low side left".
When these switches are turned on in pairs motor changes its direction
accordingly. Like, if we switch on High side left and Low side right then
motor rotate in forward direction, as current flows from Power supply
through the motor coil goes to ground via switch low side right. This is
shown in the figure below.
Similarly, when you switch on low side left and high side
right, the current flows in opposite direction and motor
rotates in backward direction. This is the basic working of H-
Bridge. We can also make a small truth table according to
the switching of H-Bridge explained above.
As already said, H-bridge can be made with the help of trasistors as well as
MOSFETs, the only thing is the power handling capacity of the circuit. If
motors are needed to run with high current then lot of dissipation is there. So
head sinks are needed to cool the circuit.
LIQUID CRYSTAL DISPLAY
INTRODUCTION:
An LCD or a liquid crystal display consists of liquid crystals between electrodes.
The arrangement consists of polarization filters which are aligned perpendicular to each
other. This arrangement doesn’t allow any visible light if there was no liquid crystal
between the filters. This arrangement is aligned in between transparent conductors.
When sufficient voltage is applied to a certain pixel, the crystal at that pixel aligns
such that no light passes through it. Therefore that particular pixel appears dark. If such
an electric field is applied for a longer period, the alignment of the crystal change and
the quality of LCD degrades. In a bigger LCD display, to provide voltage sources to
each pixel, the rows and column lines are multiplexed.
PIN DESCRIPTION OF THE LCD:
TABLE: 4.1 PIN DESCRIPTION OF LCD
LCD INTERFACE WITH MICROCONTROLLER
INTERFACING LCD TO MICROCONTROLLER
MICROCONTROLLER
PORTPINS
The LCD is generally interfaced in 8-bit mode or 4-bit mode. in this project LCD is
connected in 4-bit mode the interface connections of LCD with microcontroller are as
follows
RS of LCD is connected to p0.0 of microcontroller
EN of LCD is connected to p0.1 of microcontroller
D4 of LCD is connected to p0.4 of microcontroller
D5 of LCD is connected to p0.5 of microcontroller
D6 of LCD is connected to p0.6 of microcontroller
D7 of LCD is connected to p0.7 of microcontroller
In 8-bit mode, the complete ASCII code is sent at once along with the control
signals. But in 4-bit mode, the data is divided into two parts, i.e. MSB & LSB, and are
called upper nibble & lower nibble.
The control signals are RS, R/W & E. RS is used to select the internal registers i.e.
data register & command register. R/W is used to set the mode of LCD to read mode or
write mode. E is used as chip select and is used to push the data internally to the
corresponding registers.
To transfer the data/command in 8-bit mode, the data is written to the 8-bit data bus
after selecting the required register and setting the mode to write mode. The E signal pin
is then given a high to low signal to transfer the data.
To transfer the data/command in 4-bit mode, the higher nibble is first written to the
MSB of the data port and the E is given a high to low signal. After a little delay or when
the LCD is not busy, the lower nibble is transferred in the same procedure.
LCD COMMANDS
Chapter 4
Software implementation
4.1 RIDE
Please note that in this page RIDE will reference to RIDE6 software which
supports 8051, XA and other derivates. For ARM, ST7 and STM8 family the software is
RIDE7.
RIDE is a fully featured Integrated Development Environment (IDE) that
provides seamless integration and easy access to all the development tools. From editing
to compiling, linking, debugging and back to the start, with a Simulator, ICE, Rom
Monitor or other debugging tools, RIDE conveniently manages all aspects of the
Embedded Systems development with a single user interface.
Fig: RIDE
Multi-file Editor
RIDE is based on a fast multi-document editor designed to meet the specific
needs of programming. The various methods, menus, commands, and shortcuts are all
fully compliant with the Microsoft® specifications for Windows 2000, XP and NT.
Classic commands, such as string search and block action are integrated. Advanced
features such as Matching Delimiter (parenthesis, brackets), Grep (multi-file search) and
Indenter are integrated as well. The customizable color-highlighting feature is very useful
to indicate specific syntactic elements as they appear in the source file: keywords,
comments, identifiers, operators, and so on. The color-highlighting feature is
automatically keyed to the intrinsic file type (which means, it works differently for C and
assembler).This permits the user to identify quickly and easily those parts of the code
responsible for syntax errors.
HTTP://WWW.RAISONANCE.COM/PRODUCTS/INFO/RIDE.PHP - TOP
Project Manager:
The project manager creates links between the various files that includes a project
and the tools necessary to create that project. A project is dedicated to a particular target:
8051, XA, or other microcontrollers. The linker manages object and library files, and
output format conversion as necessary.
Fig Project Manager
Tree-structured projects ease the management of the most complex applications
(bank switching, flash, multi-processor, multi-module...). The ‘Project Make’ command
directs the integrated "make" utility to build or rebuild the target programs for the current
project. To avoid wasting time, each source file will be translated by its associated tool
only if any of its dependencies are found to be out of date. Dependency analyses, even
directly or indirectly included files, are automatic.
Options can be defined as global (for all the files) or as local (for a specific node or file).
Individual attributes can be set for any file in the project. Similarities between the
different tools make migration from one processor family to another immediate and easy,
permitting multi-processor projects.
HTTP://WWW.RAISONANCE.COM/PRODUCTS/INFO/RIDE.PHP-TOP.
The Message Window and the On-line Help:
The message window displays all warning, error, and progress messages
generated during the processing of files associated with each project.
Clicking on an error string in the message window automatically positions the cursor at
the point of that error in the source code window.
The Online help system is context-sensitive and provides information on nearly
all aspects of RIDE. A specific help file is supplied with each tool driven by the IDE ('C'
Compiler, Assembler, Linker, and RTOS). Online menu hints appear on the status line
whenever you select a menu command.
Fig Message
HTTP://WWW.RAISONANCE.COM/PRODUCTS/INFO/RIDE.PHP-TOP.
The Script Language:
Most RIDE commands can be run from a script file. Scripts are written in a C-like
language, and are interpreted at execution time. With the script language, most repetitive
tasks can be done automatically thus speeding up operations and reducing the probability
of errors. Scripts are very useful for Hardware Testing (board, emulator) and to initialize
the system to a known status, but can also be conveniently used for other tasks such as
creating very complex breakpoints or redirecting some output to a file to run a 'batch'
debug session.
HTTP://WWW.RAISONANCE.COM/PRODUCTS/INFO/RIDE.PHP-TOP.
Context Saving:
When a project is closed, the whole associated context is saved (open file list,
window size and position etc.). Settings associated with the debugger are also saves such
as breakpoints, watches etc...
HTTP://WWW.RAISONANCE.COM/PRODUCTS/INFO/RIDE.PHP-TOP
Integrated High-level Debug:
RIDE provides a fully integrated source-level debugging environment. All
information necessary is derived from the translators used to accomplish each step of the
process. This includes mundane aspects such as "path names", and source code specific
information such as details of complex data types.
With the simple click of a mouse button, the user can select among several
powerful capabilities: simulate, monitor, or emulate. The fast smooth integration given by
RIDE promotes a feeling of familiarity and ease of use, while providing a level of
comfort and efficiency that reduces the most difficult and complex applications to tasks
that are easily managed. This seamless progression of the "code-translate-link-debug-
test" cycle is the result of perfect communication between the programming tools and the
debugger. This is the heart of RIDE.
Fig : Debugger
Integral Simulation:
RIDE includes simulation engines for most 8051, and XA derivatives. The
simulator/debugger is cleanly integrated into the presentation Windows. A wide range of
'views' can be selected to provide flexible direct examination of all memory spaces as
well the all internal peripherals. The simulation engines perform detailed and faithful
simulations (including IDLE or Power down modes), of all peripherals (including
interrupt and watchdog events) present on the selected component.
Advanced Features
RIDE provides a rich variety of 'views' into an application. These views or
windows are associated with control commands like complex breakpoints or high level
trace recording.
HTTP://WWW.RAISONANCE.COM/PRODUCTS/INFO/RIDE.PHP - TOP
4.2 ISP 3.0
Introduction
This ISP Programmer can be used either for in-system programming or as a stand-
alone spi programmer for Atmel
ISP programmable devices. The programming interface is compatibe
to STK200 ISP programmer hardware so the users of STK200 can also use the
software which can program both the 8051 and AVR series devices.
Hardware
The power to the interface is provided by the target system. The 74HCT541 IC
isolates and buffers the parallel port signals. It is necessary to use the HCT type IC in
order to make sure the programmer should also work with 3V type parallel port.
The printer port buffer interface is same as shown in figure 1.For the u-
controllera40pinZIFsocketcanbe used. This programmer circuit can be use to program
the 89S series devices and the AVR series device switches are pin compatible to 8051,
like 90S8515. For other AVR series devices the user can make an adapter board for 20,
28 and 40 pin devices. The pin numbers shown in brackets correspond to PC parallel port
connector.
Software
The ISP-30a.zip file contains the main program and the i/o port driver. Place all
files in the same folder. The main screen view of the program is shown in figure 3.
Also make sure do not program the RSTDISBL fuse in ATmega8,
ATtiny26 and ATtiny2313 otherwise further spi programming is disable and you
will need a parallel programmer to enable the
spi programming. For the fuses setting consult the datasheet of the respective device.
For the auto hardware detection it is necessary to short pin 2 and 12 of
DB25connector, otherwise the software uses the default parallel port i.e. LPT1.
Following are the main features of this software,
Read and write the Intel Hex file.
Read signature, lock and fuse bits.
Clear and Fill memory buffer.
Verify with memory buffer.
Reload current Hex file.
Display buffer checksum.
Program selected lock bits & fuses.
Auto detection of hardware.
Note: The memory buffer contains both the code data and the eeprom data
for the devices which have eeprom memory. The eeprom memory address
in buffer is started after he code memory, so it is necessary the hex file should contains
the eeprom start address after the end of code memory last address i.e. for 90S2313 the
start address for eeprom memory is 0x800.
The software does not provide the erase command because th
s function is performed automatically during device programming. If you
are required to erase the controller, first use the clear
buffer command then program the controller, this will erase the controller and also set the
AVR device fuses to default setting.
Fig Main screen of the program ISP-Pgm Ver 3.0a
4.3 EMBEDDED ‘C’
Ex: Hitec – c, Keil – c
HI-TECH Software makes industrial-strength software development tools and C
compilers that help software developers write compact, efficient embedded processor
code.
For over two decades HI-TECH Software has delivered the industry's most
reliable embedded software development tools and compilers for writing efficient and
compact code to run on the most popular embedded processors. Used by tens of
thousands of customers including General Motors, Whirlpool, Qualcomm, John Deere
and many others, HI-TECH's reliable development tools and C compilers, combined with
world-class support have helped serious embedded software programmers to create
hundreds of breakthrough new solutions.
Whichever embedded processor family you are targeting with your software,
whether it is the ARM, PICC or 8051 series, HI-TECH tools and C compilers can help
you write better code and bring it to market faster.
HI-TECH PICC is a high-performance C compiler for the Microchip PIC micro
10/12/14/16/17 series of microcontrollers. HI-TECH PICC is an industrial-strength ANSI
C compiler - not a subset implementation like some other PIC compilers. The PICC
compiler implements full ISO/ANSI C, with the exception of recursion. All data types are
supported including 24 and 32 bit IEEE standard floating point. HI-TECH PICC makes
full use of specific PIC features and using an intelligent optimizer, can generate high-
quality code easily rivaling hand-written assembler. Automatic handling of page and
bank selection frees the programmer from the trivial details of assembler code.
Embedded C Compiler
ANSI C - full featured and portable.
Reliable - mature, field-proven technology.
Multiple C optimization levels.
An optimizing assembler.
Full linker, with overlaying of local variables to minimize RAM usage.
Comprehensive C library with all source code provided.
Includes support for 24-bit and 32-bit IEEE floating point and 32-bit long data
types.
Mixed C and assembler programming.
Unlimited number of source files.
Listings showing generated assembler.
Compatible - integrates into the MPLAB IDE, MPLAB ICD and most 3rd-party
development tools.
Runs on multiple platforms: Windows, Linux, UNIX, Mac OS X, and Solaris.
Embedded Development Environment.
PICC can be run entirely from the. This environment allows you to manage all of
your PIC projects. You can compile, assemble and link your embedded application with a
single step.
Optionally, the compiler may be run directly from the command line, allowing
you to compile, assemble and link using one command. This enables the compiler to be
integrated into third party development environments, such as Microchip's MPLAB IDE.