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1. STATUS REGISTER TA ANER Ea GENERAL PURPOSE MEMORY MAPPING Coetu PACKAGE AND PIN DETAIL OF 590 TEMPERATURE CONVERTION SCALE CALIBERATION AND ERRORS IN AD590 PIN DETAILS AND EQUIVALENT CIRCUITOF TIP PIN DETAILS AND EQUIVALENT CIRCULFOF TIED BC347 PIN DETAILS 24 eher end ILM 324 PIN DE TAI S wiciunccnsnpsiosageagunesscangssanonses LM 311 PIN DETAILS es ss ess r rse ero exero ten CIRCUIT MICROCONTROLLER SECTION CIRCUIT MOTOR DRIVE FUNCTIONAL BLOCK DIAGRAM FUNCTIONAL FLOW LIST OF TABLES TABLE TECHNICAL DETAILS OF TIP 122 TECHNICAL DETAILS OF TIP 127 Copyright stunbozo live com Duplicate is strictly prohibited raa 10 toe 13 T 15 16 18 seen 25 27 28 30 31 33 T 23 36 T 37 yide 38 40 41 PAGE NO 31 32 ii 2 3 TECHNICAL DETAILS OF BC 547 33 4 1 LOGIC TABLE FOR H BRIDGE 39 iv INTRODUCTION 1 1 FIRE FIGHTING ROBOT FFR Embedded system the exact definition is the system designed using microprocessor or micro controller may be both combined to perform the specified task Here we are using the m2. iCallector Emitter Voltage TIP120 TIP121 TIF 122 SolectorGurent toe J f BeseCumemipc Collector Dissipation T4 225 _ Collector Dissipation Junction Temperature 150 Table 3 1 Technical details of TIP 122 Copyright stunbozo live com 42 Duplicate is strictly prohibited 3 2 2 TIP125 126 127 Medium Power Linear Switching Applications PNP EPITAXIAL SILICON DARLINGTON TRANSISTOR Base Collector Emitter Fig 3 5 TIP125 126 127 Copyright stunbozo live com 43 Duplicate is strictly prohibited Fig 3 6 Equivalent circuit of TIP125 126 127 Copyright stunbozo live com Duplicate is strictly prohibited 44 ABSOLUTE MAXIMUM RATINGS Ta 25 Characteristic Symbol Collector Base Voltage 125 P126 P127 Collector Emitter Voltage 129 126 127 a e per e 5 A oar Cae Ce Collector Power Dissipation Junction Temperature Storage Temperature Table 3 2 Technical details of TIP127 3 3 SIGNAL TRANSISTOR 3 3 1 BC 547 Copyright stunbozo live com Duplicate is strictly prohibited 45 NPN GENERAL PURPOSE TRANSISTOR 1 1 COLLECTOR 2 BASE 3 EMITTER Fig 3 7 BC 547 LIMITING VALUES In accordance with the Absolute Maximum Rating System IEG 134 e R Duc ie base voltage open e
3. The ATmega8 features a 10 bit successive approximation ADC The ADC is connected to an 8 channel Analog Multiplexer which allows eight single ended voltage inputs constructed from the pins of Port C The single ended voltage inputs refer to OV GND The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is held at a constant level during conversion The ADC has a separate analog supply voltage pin AVCC AVCC must not differ more than 0 3V from VCC See the paragraph ADC Noise on page 198 on how to Connect this pin Internal reference voltages of nominally 2 56V or AVCC are provided On chip The voltage reference may be externally decoupled at the AREF pin by a capacitor for better noise performance Copyright stunbozo live com 35 Duplicate is strictly prohibited 3 HARDWARE COMPONENTS 3 1 TEMPERATURE TRANSDUCER 3 1 1 PIN DETAILS AND PACKAGE TO 52 FLATPACK NG CONNECT Fig 3 0 52 used In Our project 3 1 2 FEATURES o Linear current output 1 o Wide temperature range 55 C to 150 C o Probe compatible ceramic sensor package Copyright stunbozo live com 36 Duplicate is strictly prohibited 2 terminal device voltage in current out Laser trimmed to 0 5 C calibration accuracy AD590M Excellent linearity 0 3 C over full range AD590M Wide power supply range 4 V to 30 V Sensor isolation from case Low cost O O O O 0
4. current rather than a voltage In addition power requirements are low 1 5 mWs 5 V 25 C These features make the AD590 easy to apply as a remote sensor 4 The high output impedance gt 10 M provides excellent Rejections of supply voltage drift and ripple For instance changing the power supply from 5 V to 10 V results in only a 1 yA maximum current change or 1 C equivalent error 5 The AD590 is electrically durable it withstands a forward Voltage of up to 44 V and a reverse voltage of 20V Therefore supply irregularities or pin reversal do not damage the device 3 1 5 TEMPERATURE CONVERSION SCALE Copyright stunbozo live com 38 Duplicate is strictly prohibited h T HES 290 T TES D f Do E 100 HEF 100 KAZ 1 h F 3 Kz C2 3 15 g Pe 32 R 4597 Fig 3 1 Temperature Conversion Scale 3 1 6 CALIBERATION AND ERRORS Copyright stunbozo live com Duplicate is strictly prohibited 39 ACTUAL TRANSFER FUNCTION L CALIBRATION IDEAL ERROR TRANSFER 8 FUNCTION 2984 TEMPERATURE Fig 3 2 Calibration and Errors The calibration error is a primary contributor to maximum total error in all AD590 grades However since it is a scale factor error it is particularly easy to trim Figure 3 2 shows the most elementary way of accomplishing this Copyright stunbozo live com 40 Duplicate i
5. SIGNAL TO YES EXTINGUISHER amp ADJUST THE DIRECTION IF TEMP REACHED ALARM NO MOVE FORWARD FOR SECONDS Copyright stu 57 Duplicate is strictly prohibited Fig 5 2 Functional Flow Chart 5 3 OPERATION gt The explanation are given with reference to the block diagram and flow chart fig 5 1 and fig 5 2 gt First the robot stands on its own idle condition and keeps monitor every t sec if the sensor recognizes any fire The sensor is fixed at the top of the robot on a mechanism which rotates all around 180 degrees gt If there no such signal the sequence of checking the fire in all directions is carried out periodically gt Once the sensors detect the fire the robot automatically turns its direction towards the fire gt This is done with the help of the built in 1061 resolution ADC present in the controller getting the proportional output from the sensors The successive approximation technique used to convert the analog signal to digital one internally with minimized errors the sensor detects the maximum value direction and the robot align for the direction of fire by comparing the previous maximum value detected while sensing gt We are using two ADC out of eight in the controller which is selected by software giving multiplexed signal to the multiplexer gt Then it starts moving towards the fire at every frequent distance the robot stop and verifies the dir
6. instructions are 16 or 32 bits wide the Flash is organized as 4K x 16 bits For software security the Flash Program memory space is divided into two sections Boot Program section and Application Program section The Flash memory has an endurance of at least 10 000 write erase cycles The ATmega8 Program Counter is 12 bits wide thus addressing the 4K Program memory locations 2 4 8 2 Program Memory Map Copyright stunbozo live com 28 Duplicate is strictly prohibited 5000 Application Flash Section Boot Flash Section SFFF Fig 2 9 Memory mapping 2 4 8 3 EEPROM Data Memory The ATmega8 contains 512 bytes of data EEPROM memory It is organized as a separate data space in which single bytes can be read and written The EEPROM has an endurance of at least 100 000 write erase cycles The access between the EEPROM and the CPU is described bellow specifying the EEPROM Address registers the EEPROM Data Register and the EEPROM Control Register 2 5 8 4 EEPROM Read Write Access Copyright stunbozo live com 29 Duplicate is strictly prohibited A self timing function however lets the user software detect when the next byte can be written If the user code contains instructions that write the EEPROM some precautions must be taken In heavily filtered power supplies VCC is likely to rise or fall slowly on Power up down This causes the device for some period of time to run at a voltage lower than specified as mini
7. Analog Comparator should be disabled in all sleep modes Otherwise the Internal Voltage Reference will be enabled independent of sleep mode 2 8 System Control and Reset Resetting the AVR During Reset all I O Registers are set to their initial values and the program starts execution from the Reset Vector If the program never enables an interrupt Source the Interrupt Vectors are not used and regular program code can be placed at these locations This is also the case if the Reset Vector is in the Application section while the Interrupt Vectors are in the boot section or vice versa The I O ports of the AVR are immediately reset to their initial state when a reset source goes active This does not require any clock source to be running After all reset sources have gone inactive a delay counter is invoked stretching the internal reset This allows the power to reach a stable level before normal operation starts The user through the CKSEL Fuses defines the time out period of the delay counter Reset Sources Copyright stunbozo live com 31 Duplicate is strictly prohibited The ATmega8 has four sources of Reset Power on Reset The MCU is reset when the supply Voltage is below the Power on Reset threshold VPOT External Reset The MCU is reset when a low level is present on the RESET pin for longer than the minimum pulse length Watchdog Reset The MCU is reset when the Watchdog Timer period expires and
8. a C Compiler for a controller executing on a PC is now familiar Due to numerous improvements the Raisonance RC compiler version 3student version generally it is called as Ride RC is one of the most efficient compilers based on usual benchmarks results These improvements concern Code factorization common sub expressions has been made more efficient Registers usage has been highly optimized All libraries have been re examined and optimized We are using on board programming to flash the micro Controller A 6 pin connector is provided for this purpose in the printed circuit board PCB Copyright stunbozo live com 60 Duplicate is strictly prohibited 6 3 SIMULATOR The outstanding feature of the simulator is the ability of the user to construct the screens that shows various parts of the micro controller Each screen is made up of separate a window that displays internal CPU registers and code and Data memory areas The screen set can be saved as a disk file and used for one type of problem another screen can be configured for a different type of problem and loaded when needed Copyright stunbozo live com 61 Duplicate is strictly prohibited The 8051 Micro controller Architecture Programming amp Applications The 8051 Micro controller And Embedded system Electronics for you Elector Electronics Ride AVR Compiler manual Universal Programmer Data sheets Copyright stunbozo live com Duplicate
9. combines a rich instruction set with 32 general purpose working registers All the 32 registers are directly connected to the Arithmetic Logic Unit ALU allowing two independent registers to be accessed in one single instruction executed in one clock cycle The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC micro controllers The ATmega8 is low power CMOS 8 bit micro controller based on the AVR RISC Architecture By executing powerful instructions in a single clock cycle the ATmega8 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to Optimize power consumption versus processing speed The AVR core combines a rich instruction set with 32 General purpose working registers All the 32 registers are directly connected to the Arithmetic Logic Unit ALU allowing two independent registers to be accessed in one single instruction executed in one clock cycle The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC micro controllers The device is manufactured using Atmel s high density non volatile memory technology The Flash Program memory can be reprogrammed In Copyright stunbozo live com 15 Duplicate is strictly prohibited System through an SPI serial interface by a conventional non volatile memory programmer or by an On chip boot program running on the AVR core Th
10. 0 3 1 3 GENERAL DESCRIPTION The AD590 is a 2 terminal integrated circuit temperature transducer that produces an output current proportional to Absolute temperature For supply voltages between 4 V and 30 V the device acts as a high impedance constant current regulator passing 1 A K Laser trimming of the chip s thin film resistors is used to calibrate the device to 298 2 uA output at 298 2 K 25 C The AD590 should be used in any temperature sensing application below 150 C in which conventional electrical temperature sensors are currently employed The inherent low cost of a monolithic integrated circuit combined with the elimination of support circuitry makes the AD590 an attractive alternative for many temperature measurement situations Linearization circuitry precision voltage amplifiers resistance measuring circuitry and cold junction compensation are not needed in applying the AD590 3 1 4PRODUCT HIGHLIGHTS 1 The AD590 is a calibrated 2 terminal temperature sensor requiring only a dc voltage supply 4 V to 30 V Costly transmitters filters lead wire compensation and Linearization circuits are all unnecessary in applying the device Copyright stunbozo live com 37 Duplicate is strictly prohibited 2 State of the art laser trimming at the wafer level in conjunction with extensive final testing ensures that AD590 units are easily interchangeable 3 Superior interface rejection occurs because the output is a
11. 00 Write Erase Cycles 1 K Byte Internal SRAM Programming Lock for Software Security Copyright stunbozo live com 13 Duplicate is strictly prohibited 2 2 2 Peripheral Features Two 8 bit Timer Counters with Separate Pre scalar one Compare Mode One 16 bit Timer Counter with Separate Pre scalar Compare Mode and Capture Mode Real Time Counter with Separate Oscillator Three PWM Channels 8 channel ADC in TQFP and MLF package Eight Channels 10 bit Accuracy 6 channel ADC in PDIP package Eight Channels 10 bit Accuracy Byte oriented Two wire Serial Interface Programmable Serial USART Master Slave SPI Serial Interface Programmable Watchdog Timer with Separate On chip Oscillator On chip Analog Comparator 2 2 3 Special Features Power on Reset and Programmable Brown out Detection Internal Calibrated RC Oscillator External and Internal Interrupt Sources Five Sleep Modes Idle ADC Noise Reduction Power save Power down and Standby 2 2 4 I O and Package e 23 Programmable I O Lines e 28 lead PDIP 32 lead TQFP and 32 pad MLF e Operating Voltages 2 7 5 5V ATmega8L used in our project 4 5 5 5 ATmega8 e Speed Grades 0 8 MHz ATmega8L 0 16 MHz ATmega8 e Power Consumption at 4 Mhz 3V 25 C Active 3 6 mA Idle Mode 1 0 mA Copyright stunbozo live com 14 Duplicate is strictly prohibited Power down Mode 0 5 uA 2 3 OVERVIEW The AVR core
12. Arbitration Support Up to 400 kHz Data Transfer Speed Slew rate Limited Output Drivers Noise Suppression Circuitry Rejects Spikes Bus Lines Fully Programmable Slave Address with General Call Support Address Recognition Causes Wake up When AVR is in Sleep Mode 2 10 2 Analog Comparator The Analog Comparator compares the input values on the positive pin AINO and negative pin AINI When the voltage on the positive pin AINO is higher than the voltage on the negative pin AINI the Analog Comparator Output ACO 15 set The comparator s output can be set to trigger the Timer Counterl Input Capture function In addition the comparator can trigger a separate interrupt exclusive to the Analog Comparator The user can select Interrupt triggering on comparator output rise fall or toggle Copyright stunbozo live com 34 Duplicate is strictly prohibited 2 10 3 Analog to Digital Converter Features 10 bit Resolution 0 5 LSB Integral Non linearity e 2 LSB Absolute Accuracy 13 260 us Conversion Time Up to 15 kSPS at Maximum Resolution 6 Multiplexed Single Ended Input Channels 2 Additional Multiplexed Single Ended Input Channels TQFP and MLF Package only Optional Left Adjustment for ADC Result Readout e 0 VCC ADC Input Voltage Range Selectable 2 56V ADC Reference Voltage Free Running or Single Conversion Mode Interrupt on ADC Conversion Complete Sleep Mode Noise Cancellers
13. As inputs Port B pins that are externally pulled low will source current if the pull up resistors are activated The Port B pins are tri stated when a reset condition becomes active even if the clock is not running Depending on the clock selection fuse settings PB6 can be used as input to the inverting Oscillator amplifier and input to the internal clock operating circuit Depending on the clock selection fuse settings PB7 can be used as output from the inverting Oscillator amplifier If the Internal Calibrated RC Oscillator is used as chip clock source PB7 6 is used as TOSC2 1 input for the Asynchronous Timer Counter2 if the AS2 bit in ASSR is set PORT C 5 0 Port C is a 7 bit bi directional I O port with internal pull up resistors selected for each bit The Port C output buffers have symmetrical drive characteristics with both high sink and source capability As inputs Port C pins that are externally pulled low will source current if the pull up resistors Copyright stunbozo live com 21 Duplicate is strictly prohibited are activated The Port C pins are tri stated when a reset condition becomes active even if the clock is not running PC6 RESET If the RSTDISBL Fuse is programmed PC6 is used as I O pin Note that the electrical characteristics of PC6 differ from those of the other pins of Port C If the RSTDISBL Fuse is un programmed PC6 is used as a Reset input A low level on this pin for longer than t
14. FIRE FIGHTING ROBOT A PROJECT REPORT Submitted by S KANNAN R KARTHIKEYAN S SATHISH KUMAR in partial fulfillment for the award of the degree of BACHELOR OF ENGINEERING in ELECTRICAL AND ELECTRONICS ENGINEERING MAHENDRA ENGINEERING COLLEGE NAMAKKAL ANNA UNIVERSITY CHENNAI 600025 MAY 2006 Copyright stunbozo live com Duplicate is strictly prohibited ANNA UNIVERSITY CHENNAI 600025 BONAFIDE CERTIFICATE Certified that this project report FIRE FIGHTING ROBOT is the Bonafide work _ KANNAN S KARTHIKEYAN R SATHISHKUMAR S 7 who carried out the project work under my Supervision SIGNATURE SIGNATURE PROF K K SELVAM MSS G BALAJI B E HEAD OF DEPARTMENT SUPERVISOR Electrical and Electronics Engineering LECT EEE Mahendra Engineering College Electrical and Electronics Engineering Mahendra Engineering College Mallasamudram W Mallasamudram W Namakkal Dt Namakkal Dt Tamil nadu Tamil nadu Pin code 637503 Pin code 637503 Copyright stunbozo live com Duplicate is strictly prohibited ACKNOWLEDGEMENT We take this opportunity to express our gratitude to all those who have helped us in completing this project We are greatly indebted to our magnificent chairman Shri M G BHARATHKUMAR Ed M LS T E whose progressive ideal added with the far sighted counsels of our benevolent secretary Smt VALLIYAMMAL M A PH D DIPLOMA IN FRENCH has shouldered our en
15. Fig 1 3 shows the sensor rotational position and limit sensor switches One end is all the switches are connected to logical low and remaining pin is connected directly to the controller ports So the rotation of the sensor is guided through these switches There is already internal pull ups so no need of external one when the switches open normally the pin is logically high and the sensor reach the end the switch close the logical high change to low that taken into account and reversal of motor or sequential program changes Copyright stunbozo live com 55 Duplicate is strictly prohibited 5 FUNCTIONAL DESCRIPTIONS 5 1 BLOCK DIAGRAM ALARM FIRE CIRCUIT EXTINGUISHER TEMPERATURE MICRO WHEEL SENSOR CONTROLLER MOTORS IR FLAME DETECTOR SENSOR MOTOR Fig 5 1 FUNCTIONAL BLOCK DIAGRAM OF FFR The above Fig 5 1 shows the block diagram of FFR the functional blocks are indicated and the action or command direction are indicated clearly The individual blocks and circuit of each one is explained in the following sections The following flow chart gives the full functional idea of the whole project Copyright stunbozo live com 56 Duplicate is strictly prohibited 5 2 FUNCTIONAL FLOW CHART SENSOR MONITORING SEQUENCE IF FLAME CALL DELAY DETECTED YES ROTATE ROBOT TOWARTS THE DIRECTION OF FLAME FIND THE EXACT DIRECTION IF DIRECTION IS CORRECT YES CHECK THE TEMPERATURE SENSOR
16. Instruction Execute ath Instruction Felch 1 31 1 1 1 1 1 Fig 2 3 The Parallel Instruction Fetches and Instruction Executions T T2 T3 T4 1 I 1 1 1 1 1 1 1 U U Execution I 1 I 1 Register Operands Fetch I I 1 LU LU ALU Operation gt i Result Write Back M 1 1 Fig 2 4 The single ALU Operations Copyright stunbozo live com 19 Duplicate is strictly prohibited 2 3 3 PIN CONFIGURATION 1 PDIP PDIP Pos 28 OPCs ADCE SCL AND Poo 2 zr PCa PCa ADR INTO g4 25 ADC2 INTs Pags PCA ADCH IXCKITo PD4 za ADCO vec OF GND GND Q AREF XTaL 09 zx Hacc 210802 PET 10 i 74 POS 11 MISO 12 i7 08 002 PEF 13 ESOC PBa D 14 15 0214 Fig 2 5 Pin diagram of ATmega8 Copyright stunbozo live com 20 Duplicate is strictly prohibited 2 3 4 INDIVIDUAL PIN DETAILS VCC Digital supply voltage GND Ground XTALI XTAL2 TOSCI TOSC2 PORT B PB7 PB0 Port B is an 8 bit bi directional I O port with internal pull up resistors selected for each bit The Port B output buffers have symmetrical drive characteristics with both high sink and source capability
17. PBATUBRES 4 bras iE od 3 1 3 GENERAL DESCRIPTION 3 1 4 PRODUCT HIGHLIGHT 3 1 5 TEMPERATURE CONVERSION SCALE 3 1 6 CALIBERATION AND ERROR Sy 3 2 3 2 1 TECHNICAL AND PIN DETAILS 122 3 2 2 TECHNICAL AND PIN DETAILS 127 Copyright stunbozo live com Duplicate is strictly prohibited 3 3 GENERAL PURPOSE TRANSISTOR 33 3 3 TECHNICALAND PIN DETAILS OF BC 547 33 3 4 PHOTO DIODE 34 3 4 1 SCIENCE OF PHOTONS AND BIASINGCUBRENT 35 3 5 35 3 5 1 LM 324 LOW POWER QUARD OP AMP 35 3 5 2 LM 31I VOLTAGE COMPARATOR 36 4 CICUIT DIAGRAM AND DESCRIPTION 37 4 1 MICRO CONTROLLER SECTION 37 4 2 MOTOR DRIVE 38 4 3 FLAME SENSOR CIR CUED ectetuer 55 4 4 TEMPERATURE SENSOR CIRCUIT 56 4 5 CICUIT DESCRIPTION 57 4 2 1 LOGIC TABLE FOR MOTOR DRIVE 56 5 FUNCTIONAL DESCRIPTION 57 5 1 BLOCK DIAGRAM 58 3 2 FLOW CHART tae 29 S J OPERATION a 60 6 SOFTWARE 61 6 1 ASSEMBLY LANGUAGE AND ASSEMBLER 62 6 2 C LANGUAGE AND EMBEDDED SYSTEM 63 6 3 SIMULATORS sse 64 Copyright stunbozo live com Duplicate is strictly prohibited 6 4 PROGRAM H 65 ABSTRACT There
18. are many possibilities to get fire in an Industry or any remote areas For example in cotton mills garments fuel storages etc electric leakage causes huge damage also it s a worst case scenario which cause heavy loss not only financially also surroundings got affected Nowadays the Fire Extinguishers are implemented in industries which is mostly manual one or sensible announciators In our project we choose a desired application which open the door for modern and future world Robotics is the emerging solution to protect the human and their wealth and surroundings The aim of our project is to design a FIRE FIGHTING ROBOT using embedded system We have chosen the ATMEGA 8 AVR controller because it is a high performance and low power 8 bit controller which exactly having the required features This project helps to improve the safety to us in our day to day life LIST OF FIGURES FIG NO FIGURES PAGE NO Copyright stunbozo live com Duplicate is strictly prohibited 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 6 2 9 3 0 3 1 3 2 3 3 amp 3 4 3 5 amp 3 6 3 7 3 8 3 9 4 1 4 2 4 3 3 10 T NO 3 1 3 2 MICROCONTROLLER BLOCK DIAGRAM ATMEGA 8 AVR MICROCONTROLLER BLOCK DIAGRA Mou csccsstasssssisiessvasaseveecsstesesees PARALLEL FETCHING AND EXECUTION TIMING DIAGRAM SINGLE ALU OPERATION TIMING PIN DIAGRAM OF ATMEGA 8 CONTROLLER MICROCONTROLLER ARCHITECTURE
19. bited 4 0 CIRCUIT DIAGRAMS 4 1 MICROCONTROLLER SECTION CIRCUIT DIAGRAM OF FFR MICRO CONTROLLER SECTION Fig 4 1 CIRCUIT DIAGRAM CONTROLLER SECTION Copyright stunbozo live com 50 Duplicate is strictly prohibited 4 2 MOTOR DRIVE CONTROL CIRCUIT LM 311 COMPARATOR CONTROLLED H BRIDGE MOTOR DRIVER CIRCUITS ROB PAISLEY 2001 TWO INPUT H BRIDGE CIRCUIT 12V P aol MESS Fd r4 Yoo 5 01 0 Yoo 5Y S N ES N N E y n 2 4700 N INPUT INPUT B LOW OFF 3 4 LOW OFF j x B Se Na TOTS a x J M N i N 1K 04 02 2 STROBE STROBE Fig 4 2 MOTOR CONTROL DRIVE 4 2 1 CIRCUIT DESCRIPTION The above circuit is designed to control the D C motor on off and direction The logical inputs are fed to the input terminals INPUT A and B There is a hardware lock which protect the working components even though the inputs are similar This protection is done through the strobe control in the LM 311 op amp when this pin is grounded through the the outputs are tri stated the circuit is idle and only leakage current flows in the H Bridge shown in fig 4 2 The ops amp LM324 are working for buffer action and avoid the loading of the micro controller Copyright stunbozo live com 51 Duplicate
20. correct program execution The CPU must therefore be able to access memories perform calculations control peripherals and handle interrupts 2 4 2 Architectural Overview Data Bus B bit Status and Control Registres Progam LEE Preqram Counter Memory Control Lines Drect Addressing Addressing VO Modulet VO Module 2 VO Module n SRAM EEPROM Fig 2 6 ARCHITECTURE OF AVR MICROCONTROLLER Copyright stunbozo live com 23 Duplicate is strictly prohibited In order to maximize performance and parallelism the AVR uses Harvard architecture with separate memories and buses for program and data Instructions in the Program memory are executed with a single level pipelining While one instruction is being executed the next instruction is pre fetched from the Program memory This concept enables instructions to be executed in every clock cycle The Program memory is In System Reprogrammable Flash memory The fast access Register File contains 32 x 8 bit general purpose working registers with a single clock cycle access time This allows single cycle Arithmetic Logic Unit ALU Operation In a typical ALU operation two operands are output from the Register File the operation is executed and the result is stored back in the Register File in one clock cycle Program Flash memory space is divided in two sections the Boot program section and the Application program s
21. deavors and hauled us to meritorious heights We would like to express our sincere thanks to Prof K SUKUMARAN Principal Mahendra engineering college Mallasamudram for his blessings which as enabled this project to be a completed one We express our deep sense of gratitude to Prof B E MS Head of the Department Mahendra engineering college We are extremely thankful to Ms G BALAJI B E our internal guide for her valuable guidance and suggestions throughout the project No words can adequately express our deep gratitude to Mr B N PRAKASH B E for having consented to guide us Finally we sincerely thank our teachers family members friends and well wishers for their moral support throughout this project Copyright stunbozo live com 3 Duplicate is strictly prohibited TABLE OF CONTENTS CHAPTER NO TITLE PAGE NO 1 ABSTRACT i 2 LIST OF FIGURES H 3 LIST OF TABLES 4 LIST OF SYMBOLS iv 1 INTRODUCTION 1 1 1 FIRE FIGHTING ROBOT 1 1 2 EMBEDED SYSTEM 1 1 3 COMPARING MICRO PROCESSOR AND CONTROLLER 2 2 MICRO CONTROLLER 2 2 1 GENERAL ICROCONTROLLER 3 2 2 FEATURES OF ATMEGA8 AVR CONTROLLER 4 2 2 1 GENERAL FEATURES 4 2 2 2 PHERIPHERAL FEATURES 4 2 2 3 SPECIAL FEATURES 5 2 2 4 AND 5 Copyright stunbozoGlive com 4 Duplicate is strictly pr
22. e boot program can use any interface to download the application program in the Application Flash memory Software in the Boot Flash Section will continue to run while the Application Flash Section is updated providing true Read While Write operation By combining an 8 bit RISC CPU with In System Self Programmable Flash on a monolithic chip the Atmel ATmega8 is a powerful micro controller that provides a highly flexible and cost effective solution to many embedded control applications 2 3 1 ATMEGA8A VR MICROCONTROLLER BLOCK DIAGRAM Copyright stunbozo live com 16 Duplicate is strictly prohibited TESET PCO POS PRD PET voc RT n PORTC DRIVERS BUFFERS DIGITAL INTERFACE MUX amp E INTEFEACE GND TINERS pum INTERNAL OSCILLATOR WATCHDO INSTRUCTION MCU CTRL DECODER CONTROL STATUS 11 REGISTER AVR CPU PORTD DHIVERE BLIFFERE 1 STRING PDO PD7 Fig 2 2 BLOCK DIAGRAM OF ATMEGA 8 AVR Copyright stunbozo live com Duplicate is strictly prohibited 17 2 3 1 INTRODUCTION The ATmega8 provides the following features 8K bytes of In System Programmable Flash with Read While Write capabilities 512 bytes of EEPROM 1K byte of SRAM 23 General purpose I O lines 32 general purpose working registers three flexible Timer Counters with compare modes int
23. ection Both sections have dedicated Lock Bits for write and read write protection The SPM instruction that writes into the Application Flash memory section must reside in the Boot program section 2 4 3 Arithmetic Logic Unit ALU The high performance AVR ALU operates in direct connection with all the 32 general purpose working registers Within a single clock cycle arithmetic operations between general purpose registers or between a register and an immediate are executed The ALU operations are divided into three main categories arithmetic logical and bit functions Some implementations of the architecture also provide a powerful multiplier supporting both signed unsigned multiplication and fractional format See the InstructionSet section for a detailed description 2 4 4 Status Register The Status Register contains information about the result of the most recently executed arithmetic instruction This information can be used for altering program flow in order to perform conditional operations Note that Copyright stunbozo live com 24 Duplicate is strictly prohibited the Status Register is updated after all ALU Operations as specified in the Instruction Set Reference This will in many cases remove the need for using the dedicated compare instructions resulting in faster and more compact code The Status Register is not automatically stored when entering an interrupt routine and restored when returning from an in
24. ection by once Copyright stunbozo live com 58 Duplicate is strictly prohibited again detecting the direction of fire and moves towards the aim gt Once it goes nearer the temperature sensor gives the output that is greater than the set value immediately robot stops and extinguish the fire gt After extinguish the fire the alarm continues till the reset provided to the controller gt The robot is equipped with Nickel cadmium re chargeable battery through the terminal it can be charged using a 7 5 500 battery charger Copyright stunbozo live com 59 Duplicate is strictly prohibited 6 0 SOFTWARE 6 1 THE ASSEMBLY LANGUAGE AND ASSEMLER LOW LEVEL LANGUAGE An assembler is a translator machine Computer programs written using a definite set of rules the syntax are put into the assembler and hex code pops out and the source program is stored with the extension Asm normally and machine code with hex and bin The physical structure of the program is too large and not easy to understand but the memory occupied by the system is comparatively compact with others The programming is done with the mnemonics provided product information 6 2 THE C LANGUAGE AND EMBEDDED SYSTEM The C language has become the standard high level language for micro controller based applications Just as the PC is the standard for personal computing the AVR are the advanced one for 8 bit micro controller and the concept of
25. ection will continue to run while the Application Flash Section is updated providing true Read While Write operation By combining an 8 bit RISC CPU with In System Self Programmable Flash on monolithic chip the Atmel ATmega8 is a powerful micro controller that provides a highly flexible and cost effective solution to many embedded control applications Copyright stunbozo live com 18 Duplicate is strictly prohibited The ATmega8 AVR is supported with a full suite of program and system development tools including C compilers macro assemblers and program debugger simulators In Circuit Emulators and evaluation kits 2 3 2 INSTRUCTION EXECUTION TIMIMG This section describes the general access timing concepts for instruction execution The CPU clock CPU directly generated from the selected clock drives the AVR CPU source for the chip No internal clock division is used Figure 2 2 shows the parallel instruction fetches and instruction executions enabled by the Harvard architecture and the fast access Register File concept This is the basic pipelining concept to obtain up to 1 MIPS per MHz with the corresponding unique results for functions per cost functions per clocks and functions per power unit T2 T8 T4 1 1 1 1 1 1 1 1 i CPU H H 1st instruction tst Instruction Execute L i 2nd Instruction Fetch T 1 and Instruction Execule i i Instruction Fateh LT ard
26. eration LSB First or MSB First Data Transfer e Seven Programmable Bit Rates End of Transmission Interrupt Flag Write Collision Flag Protection Wake up from Idle Mode Double Speed CK 2 Master SPI Mode 2 10 USART The Universal Synchronous and Asynchronous serial Receiver and Transmitter USART are a highly flexible serial communication device The main features are Full Duplex Operation Independent Serial Receive and Transmit Registers Asynchronous or Synchronous Operation Master or Slave Clocked Synchronous Operation High Resolution Baud Rate Generator Supports Serial Frames with 5 6 7 8 or 9 Data bits and 1 or 2 Stop Bits Copyright stunbozo live com 33 Duplicate is strictly prohibited Odd or Even Parity Generation and Parity Check Supported by Hardware Data Overrun Detection Framing Error Detection Noise Filtering Includes False Start Bit Detection and Digital Low Pass Filter Three Separate Interrupts on TX Complete TX Data Register Empty and RX Complete Multi processor Communication Mode Double Speed Asynchronous Communication Mode 2 10 1 Two wire Serial Interface Features Simple Yet Powerful and Flexible Communication Interface only two Bus Lines Needed Both Master and Slave Operation Supported Device can Operate as Transmitter or Receiver 7 bit Address Space Allows up to 128 Different Slave Addresses Multi master
27. ernal and external interrupts a serial programmable USART a byte oriented Two wire Serial Interface a 6 channel ADC eight channels in TQFP and MLF packages with 10 bit accuracy a programmable Watchdog Timer with Internal Oscillator an SPI serial port and five software selectable power saving modes The Idle mode stops the CPU while allowing the SRAM Timer Counters SPI port and interrupt system to continue functioning The Power down mode saves the register contents but freezes the Oscillator disabling all other chip functions until the next Interrupt or Hardware Reset In Power save mode the asynchronous timer continues to run allowing the user to maintain a timer base while the rest of the device is sleeping The ADC Noise Reduction mode stops the CPU and all I O modules except Asynchronous timer and ADC to minimize switching noise during ADC conversions In Standby mode the crystal resonator Oscillator is running while the rest of the device is Sleeping This allows very fast start up combined with low power consumption The device is manufactured using Atmel s high density non volatile memory technology The Flash Program memory can be reprogrammed In System through an SPI serial Interface by a conventional non volatile memory programmer or by an On chip boot program running on the AVR core The boot program can use any interface to download the application program in the Application Flash memory Software in the Boot Flash S
28. ge carriers separate and move in opposite directions The trick in a photodiode is to collect the photon induced charge carriers as current or voltage at the electrodes before they have a chance to recombine This is achieved using a pn or p i n diode junction structure hence the term p i n photodiode An n type semiconductor material is doped to produce an excess of electrons whereas a p type material has an excess of holes or an electron deficiency At the pn junction this disparity creates a concentration gradient that causes electrons to diffuse into the p layer and holes to diffuse into the n layer This diffusion results an opposing electrical potential often referred to as an internal bias see figure 1 In a region spanning both sides of the junction this electrical force causes any charge carriers to be rapidly swept to the appropriate layer Because charge carriers cannot reside in this region it is termed the depletion region 3 5 OP AMPS Copyright stunbozo live com 47 Duplicate is strictly prohibited 3 5 1 LM324 Low Power Quad Operational Amplifiers BUTT n Po 1 ngT7PET 1 EFFET GPS uu 2 2 Fig 3 8 LM324 The LM124 series consists of four independent high gain internally frequency compensated operational amplifiers which were designed specifically to operate from a single Power supply over a wide range of voltages Operation fr
29. he minimum pulse length will generate a Reset even if the clock is not running Port D PD7 PD0 Port D is an 8 bit bi directional I O port with internal pull up resistors selected for each bit The Port D output buffers have symmetrical drive characteristics with both high sink and source capability As inputs Port D pins that are externally pulled low will source current if the pull up resistors are activated The Port D pins are tri stated when a reset condition becomes active even if the clock is not running RESET Reset input A low level on this pin for longer than the minimum pulse length will generate a reset even if the clock is not running AVCC AVCC is the supply voltage pin for the A D Converter Port C 3 0 and ADC 7 6 It should be externally connected to VCC even if the ADC is not used If the ADC is used it should be connected to VCC through a low pass filter Note that Port C 5 4 use digital supply voltage VCC AREF AREF is the analog reference pin for the A D Converter ADCT 6 TQFP and MLF Package Only In the TQFP and MLF package ADC7 6 serve as analog inputs to the A D converter These pins are powered from the analog supply and serve as 10 bit ADC channels Copyright stunbozo live com 22 Duplicate is strictly prohibited 2 4 AVR CPU CORE ARCHITECTURE 2 4 1 Introduction This section discusses the AVR core architecture in general The main function of the CPU core is to ensure
30. icro controller to perform the action that is continuously monitors the specified area whether there is any fire and automatically it goes near to the flame and extinguish the fire We are using photo diode of the TIL series are sensitive to linear polarized light in the wavelength area of 400nm 950nm If there is any presence of flame the forward current increases and confirm the fire by checking the temperature sensors output and then it gives buzzer and extinguish the fire by moving towards it 1 2 EMBEDDED SYSTEMS Embedded system can be defined as the system with a true on chip computer Embedded core computers installed in devices such as appliances vehicles medical devices and so on In an embedded system there is only one application software that is typically burned into the ROM An PC contains or connected to various embedded products such as keyboard printer modem disk controller sound card CD Rom driver mouse and so Copyright stunbozo live com 10 Duplicate is strictly prohibited on Each one of these peripherals has a micro controller inside it that performs only one task For e g inside every mouse there is a micro controller to perform the task of finding position and sending to the PC One of the most critical needs of embedded system is to decrease power consumption and space Interfacing more functions into the CPU chip does this They differ from computers in services and PCs because of limits on size po
31. is strictly prohibited 4 2 2 LOGIC TABLE FOR H BRIDGE CIRCUIT Input A Input B Motor Action U 1 Forward 1 0 Reverse 0 0 Idle 1 1 Idle Table 4 1 Logic Table for H Bridge Circuit Two set of H Bridge is used for the motion of robot and one is used for sensing the fire 1 rotates the sensor and fixes the direction of the fire We are using D C motor of type permanent magnet one the reversal is done only through change in direction of current flow through the armature The speed control is achieved by the technique pulse width modulation PWM The duty cycle is varied in hardware and also through the micro controller programming Here we are handling software technique Ex or logic gate is used to check the input data if it is same one it produces logical one output and transistor drive the Strobe pin of LM311 and for dissimilar input the strobe pin is active high and perform normal operation For switching Darlington transistors NPN and PNP Similar characteristic transistors are used TIP 122 and TIP 127 Copyright stunbozo live com 52 Duplicate is strictly prohibited 1 SENSOR CIRCUITS 4 3 Temperature Sensor Circuit vcc PORTC 0 1K Ohms 10K Ohms GND Fig 4 3 Temperature sensor Circuit The above fig 4 3 shows the temperature sensing part consists of AD 590 which is a metal package transducer also available in SOIC and flat pack and a voltage dropping resister The vol
32. is strictly prohibited REFERENCES Kenneth J Ayala Muhammad Ali Mazidi Magazine Magazine User manual Flash Programming kit From companies website OnSemi com intersil com Atmel com etc 62 FURTHER DEVELOPMENTS Here we produced the concept of detecting the fire and extinguish the fire in a remote area The application oriented developments also be incorporated such as o Fire announciators can be interfaced with the robot Area under control can be increased The signal is taken as references the robot can be move the specified address detect and extinguish the fire Trip circuits be connected to the robot which trips the electrical circuit under worst case In remote areas the intimation is done through communication from the robot which is easily established in our robot Copyright stunbozo live com 63 Duplicate is strictly prohibited Conclusion Rapidly evolving associate system technologies are changing the concepts for planning and executing operations for autonomous robotic vehicles in fire fighting operations To be effective the robotic vehicle must be capable of accurately assessing the environment and reacting to it s ever changing demands Associate systems technology can provide these capabilities through top level functions of Assessment Planning and Acting and lower level functions including System Status Situation Assessment Dynamic Plan
33. mitter oolector emitter voltage open base BC ody eritter base voltage open collector ae 12 ow peak onlectorcurrent u total power dissipation mw etoragetemperare E operating ambient enparature e f e i Table 3 3 Technical details of BC 547 3 4 PHOTO DIODE TIL 81 Copyright stunbozo live com 46 Duplicate is strictly prohibited By generating charge carriers in response to photons semiconductor structures yield robust highly linear solid state photo detectors for a variety of applications The purpose of any photo detector is to convert electromagnetic radiation into an electronic signal ideally one that is proportional to incident light intensity Because they are compact versatile and can be produced economically in high volume p i n photodiodes have become the detector of choice in applications from biomedical instrumentation to telecommunications Semiconductor materials absorb light over a characteristic wavelength range for example 250 nm to 1100 nm for silicon and 800 nm to 2 0 um for GaAs When a photon of light is absorbed it excites an electron and produces a single pair of charge carriers an electron and a hole where a hole is simply the absence of an electron in the semiconductor lattice Current passes through a semiconductor when the char
34. mum for the clock frequency used In order to prevent unintentional EEPROM writes a specific write procedure must be followed When the EEPROM is read the CPU is halted for four clock cycles before the next instruction is executed When the EEPROM is written the CPU is halted for two clock cycles before the next instruction is executed 2 5 Timer Counter Oscillator For AVR microcontrollers with Timer Counter Oscillator pins TOSCI and TOSC2 the crystal are connected directly between the pins By programming the CKOPT Fuse the user can enable internal capacitors on XTALI and XTAL2 thereby removing the need for external capacitors The Oscillator is optimized for use with a 32 768 kHz watch crystal Applying an external clock source to TOSCI is not recommended 2 6 Analog to Digital Converter ADC If enabled the ADC will be enabled in all sleep modes To save power the ADC should be disabled before entering any sleep mode When the ADC is turned off and on again the next conversion will be an extended conversion Copyright stunbozo live com 30 Duplicate is strictly prohibited 2 7Analog Comparator When entering idle mode the Analog Comparator should be disabled if not used When entering ADC Noise Reduction mode the Analog Comparator should be disabled In the other sleep modes the Analog Comparator is automatically disabled However if the Analog Comparator is set up to use the Internal Voltage Reference as input the
35. ndous Copyright stunbozo live com 11 Duplicate is strictly prohibited advancement in embedded system and development is reliability and data hiding and protecting the technology from the pirating problem as like in the discrete IC s 2 1 GENERAL MICROCONTROLLER BLOCK DIAGRAM ROM RAM MEMORY GENERAL SYSTEM PHERIPHERALS Copyright stunbozo live com 12 Duplicate is strictly prohibited Fig 2 1 BLOCK DIAGRAM OF MICRO CONTROLLER Normally micro controllers having RAM ROM Peripheral devices and I O Ports and multiplexed ports also like address bus cum data bus The functional block diagram of a micro controller is as shown in fig 2 1 The selection of controller is decided by the application and the controlled should fulfill the required features of the same with out any compromise 2 2 FEATURES OF ATMEGA 8 AVR MICRO CONROLLER 2 2 1 General Features High performance Low power AVR 8 Bit Micro controller Advanced RISC Architecture 130 Powerful Instructions Most Single clock Cycle Execution 32 x 8 General Purpose Working Registers Fully Static Operation Up to 16 MIPS Throughput at 16 MHz On chip 2 cycle Multiplier Nonvolatile Program and Data Memories 8K Bytes of In System Self Programmable Flash Endurance 10 000 Write Erase Cycles Optional Boot Code Section with Independent Lock Bits In System Programming by On chip Boot Program True Read While Write Operation 512 Bytes EEPROM Endurance 100 0
36. ning Information Management User Interface System Interface Associate system technologies are now mature and ready for implementation in the command and control architectures for autonomous fire fighting operations Thus we complete our project satisfactorily with all the components available in commercial We have finished our project with the time available and all welcome your suggestions and comments to do improvements in this project We will take your kind suggestions and comments in the right way to improve our project Copyright stunbozo live com 64 Duplicate is strictly prohibited
37. of the instructions operating on the Register File have direct access to all registers and most of them are single cycle instructions As shown in Figure 2 7 each register is also assigned a Data memory address mapping them directly into the first 32 locations of the user Data Space Although not being physically implemented as SRAM locations this Copyright stunbozo live com 27 Duplicate is strictly prohibited memory organization provides great flexibility in access of the registers as the X Y and Z pointer Registers can be set to Index any register in the file 2 4 7 Stack Pointer The Stack is mainly used for storing temporary data for storing local variables and for storing return addresses after interrupts and subroutine calls The Stack Pointer Register always points to the top of the Stack Note that the Stack is implemented as growing from higher memory locations to lower memory locations This implies that a Stack PUSH command decreases the Stack Pointer 2 4 8 AVR ATmega8 Memories This section describes the different memories in TheATmega8 The AVR architecture has two main memory spaces the Data memory and the Program Memory space In addition the ATmega8 features an EEPROM Memory for data storage All three memory spaces are linear and regular 2 4 8 1 In System Reprogrammable Flash Program memory The ATmega8 contains 8K bytes On chip In System Reprogrammable Flash memory for program storage Since all AVR
38. ohibited 2 9 OVERIE W EaR Eea Oed E 5 2 3 1 8 BLOCK DIAGRAM 7 2 3 2 INTRODUCTION 8 2 3 3 INST EXECUTION TIMING 9 2 3 3 PIN CONFIGURATION 10 2 3 4 INDIVIDUAL DETAILS 11 2 4 ATMEGE 8 AVR ARCHITUCTURE 13 2 4 1 INTRODUCTION idees eee 2 4 ARCHITECTURALOVERVIEW 13 2 4 3 ARITHMETIC LOGIC 14 2 4 4 STATUS REGISTER 14 2 4 5 GENERAL PURPOSE REGISTER SCHEME 15 2 4 6 GENERAL WORKING REGISTERS 16 2 4 7 STACK 17 2 4 8 MEMORIES 17 2 4 8 1 REPROGRAMMABLE FLASH MEMORY 17 2 4 8 2 PROGRAM MEMORY MAPING ssc ERN 18 2 4 8 3 EEPROM DATA MEMORY 2 4 8 4 EEPROM READ WRITE ACCESS 19 Copyright stunbozo live com Duplicate is strictly prohibited 2 5 TIMER COUNTER OSCILLATOR 2 6 ANALOG TO DIGITAL CONVERTER 2 7 ANALOG 2 8 SYSTEM CONTROL AND RESET 2 9 INTERFACING EXTERNAL COMMUNICATION 2 9 1 SERIAL PHERIPHERAL INTERFACE 2 10 USAR HT 2 10 1 TWO WIRE SERIAL 2 10 2 ANALOG COMPARATOR 3 HARDWARE COMPONENTS 3 1 TEMPERATURE SENSOR 3 1 1 AD590PIN DETAILS AND PACKAGE SL
39. om split power supplies is also possible and the low power supply current drain is independent of the magnitude of the power supply voltage Wide power supply range Single supply to 32V Or dual supplies 1 5V to 16V Differential Input Voltage 32V max Lead Temperature Soldering 10 seconds Input Voltage 0 3V to 32V Copyright stunbozo live com 48 Duplicate is strictly prohibited 3 5 2 LM 311 VOLTAGE COMPARATOR ID uai tL re Pa a aa mad Tm Fig 3 9 LM 311 Voltage Comparator General Description It can operate over a wider range of supply voltages from standard 15V op amp supplies down to the single 5V supply used for IC logic Their output is compatible with RTL DTL and TTL as well as MOS circuits Further they can drive lamps or relays switching voltages up to 50V at currents as high as 50 mA Both the inputs and the outputs of the LM111 LM211 or the LM311 can be isolated from system ground and the output can drive loads referred to ground the positive supply or the negative supply Offset balancing and strobe capability are provided and outputs can be wire OR ed Total Supply Voltage 36V all spec max Output to Negative Supply Voltage 50V Ground to Negative Supply Voltage 30V Differential Input Voltage 30V Input Voltage Note 1 15 Output Short Circuit Duration 10 sec Copyright stunbozo live com 49 Duplicate is strictly prohi
40. s strictly prohibited To trim this circuit the temperature of the AD590 is measured by a reference temperature sensor and R is trimmed so that VT 1 mV K at that temperature Note that when this error is trimmed out at one temperature its effect is zero over the entire temperature range In most applications there is a current to voltage conversion resistor or as with a current input ADC a reference that can be trimmed for scale factor adjustment The AD590 uses a fundamental property of the silicon transistors from which it is made to realize its temperature proportional characteristic if two identical transistors are operated at a constant ratio of collector current densities r then the difference in their base emitter voltage will be kT q In Since both k Boltzman s constant and q the charge of an Electron are constant the resulting voltage is directly proportional to absolute temperature 3 2 POWER TRANSISTORS 3 2 1 TIP120 121 122 NPN EPITAXIAL SILICON DARLINGTON TRANSISTOR Medium Power Linear Switching Applications 1 Base 2 Collector i Emitter Fig 3 3 TIP120 121 122 Copyright stunbozo live com 41 Duplicate is strictly prohibited Equivalent Circuit Fig 3 4 Equivalent Circuit of TIP120 121 122 NPN Epitaxial Darlington Transistor Absolute Maximum Ratings 25 unless otherwise noted nits Collector Base Voltage TIP 120 GU TIP121 50 TIP122 100
41. tage drop across the resister gives the proportional voltage in terms of temperature increase or decrease The output current from the ad 590 is independent of the resister connected in series because it is constant current drive unit proportional to the temperature raise The output is directly connected to the ADC channel present in the micro controller through a series protection resister of 10 ohms The sensor output adjusted to sense the flame by varying the series resister and change of voltage is achieved to meet the required variation which we can distinguish the fire and normal light rays Copyright stunbozo live com 53 Duplicate is strictly prohibited 4 4 IR Sensor circuit VCC 220K ohms PORTC 1 GND Fig 4 4 IR Sensor Circuit The above fig 1 2 shows the flame detector schematic which consists of TIL81 two lead photodiode connected in series with a resister across the VCC and GND At normal condition the diode is reverse biased no current flow in the circuit when the diode receives the photons from the fire the biasing current increases due the cumulative action of the electrons and holes collision The IR receives the fire signal because it is tuned to that wavelength which is emitted from the fire Copyright stunbozo live com 54 Duplicate is strictly prohibited 4 5 Mechanical switch Middle N Left O PORT B 1 PORT 0 GND PORT D 1 Fig 4 5 Mechanical switch connections The above
42. terrupt This must be handled by software The AVR Status Register SREG is defined as show in fig Bi T E f d4 4 3 _ SWIK RW RWO RWO RW RW RW RW RM mug 0 0 d Fig 2 7 AVR Status Register e Bit 7 1 Global Interrupt Enable e Bit 6 T Bit Copy Storage Bit 5 H Half Carry Flag e Bit4 S Sign Bi S N V e Bit 3 V Two s Complement Overflow Flag Bit 2 N Negative Flag Bit 1 Z Zero Flag Bit 0 C Carry Flag 2 4 5 General Purpose Register Schemes The Register File is optimized for the AVR Enhanced RISC instruction set In order to achieve the required performance and flexibility the Register File supports the following input output schemes Copyright stunbozo live com 25 Duplicate is strictly prohibited One 8 bit output operand and one 8 bit result input Two 8 bit output operands and one 8 bit result input Two 8 bit output operands and one 16 bit result input One 16 bit output operand and one 16 bit result input 2 4 6 CPU General Purpose Working Registers Copyright stunbozo live com Duplicate is strictly prohibited 26 Ceo Cr ox DL xnE x F CE 10 Ce 11 xiB ix 1c x 10 DY E Oxi F Xregstar Low Byte X4egister High Byte Y regstur Low Byte register Hoh Byte Zregstu Low Byta Zregsta High Byta Fig 2 8 CPU General Purpose Working Registers Most
43. the Watchdog is enabled Brown out Reset The MCU is reset when the supply voltage VCC is below the Brown out Reset threshold VBOT and the Brown out Detector is enabled Watchdog Timer The Watchdog Timer is clocked from a separate On chip Oscillator which runs at 1 MHz This is the typical value at VCC 5V See characterization data for typical values at other VCC levels By controlling the Watchdog Timer prescaler the Watchdog Reset interval can be adjusted The WDR Watchdog Reset instruction resets the Watchdog Timer The Watchdog Timer is also reset when it is disabled and when a Chip Reset occurs Eight different clock cycle periods can be selected to determine the reset period If the reset period expires without another Watchdog Reset the ATmega8 resets and executes from the Reset Vector For timing details on the Watchdog Reset refer to page 39 To prevent unintentional disabling of the Watchdog a special turn off sequence must be followed when the Watchdog is disabled Copyright stunbozo live com 32 Duplicate is strictly prohibited 2 9 INTERFACING EXTERNAL COMMUNICATION 2 9 1 Serial Peripheral Interface SPI The Serial Peripheral Interface SPI allows high speed synchronous data transfer between the ATmega8 and peripheral devices or between several AVR devices ATmega8 SPI includes the following features Full duplex Three wire Synchronous Data Transfer Master or Slave Op
44. wer consumption form factor and location e g Mobility resulting in limits on computational power memory and communication connectivity Embedded systems are increasingly common they control important devices in military government industrial and increasingly consumer contexts Some of the embedded products using micro controller are intercom telephones fax machines musical instruments televisions VCR remote controls video games micro wave copier printer cellular phones etc 1 3 COMPARING MICRO CONTROLLER AND MICROPROCESSOR The contrast between the micro controller and microprocessor is best exemplified by the fact that most microprocessor has many op codes for moving data from external memory to CPU micro controller may have one or two Microprocessor may have one or two types of bit handling instructions micro controllers will have many To summarize the microprocessor is concerned with rapid movement of code and data from external address to the chip the micro controller is concerned with rapid movements of bits with in the chip The micro controller can function as a computer with the addition of no additional external parts the microprocessor must have many additional parts to be operational 2 MICROCONTROLLER Micro controllers are having the customized terminals and user friendly interfacing and increased fan out of the individual I O ports which is accessed to our requirements The reason for this treme
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