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Industrial automation Using Microcontroller - PowerPoint

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					Industrial automation Using
      Microcontroller




  By: Engr. Tarique Rafique Memon
 Department of Electronic Engineering
         QUEST Nawabshah
                 Contents
► Introduction
► Parameters consideration     for Automation
► Selecting microcontroller
► Internal architecture   of Microcontroller
► Applications
                Introduction
Automation
►The  control of an industrial process (e.g
 manufacturing, production etc) by automatic rather
 that manual means is often called automation

►Automation  can be defined as a technology that
 uses programmed commands to operate a given
 process
  Basic building block diagram of
            Automation



Transducer
             Processing/ control   Output/ Display
Set point




                 Appliances
          Sensors/ Transducers
► Level
► Flow
► Pressure
► Temperature
► Humidity
      Controllable applications
► Motors
► Solenoid valves
► Control valves
                  Display
► Input Parameters
► Set point
► Indication for Output (alarm)
               Controller
► Takes  Input
► Verifies the conditions
► Controls the equipment &
► Displays the output
             Microcontrollers
The prime use of a microcontroller :

►   To control the operation of a machine using a fixed
    program that is stored in ROM and that does not
    change over the lifetime of the system
    Typical Microcontrollers
► The   most common microcontrollers are 8-
  bit.
► 4-bit are used in high volume very low cost
  applications
► 16 & 32 bit are used in high-end
  applications.
► Typical clock frequencies are 12 - 24 MHz
          Different manufacturers of
                microcontroller
► Intel
► Atmel
► Philips
► Dallas Semiconductors
► Microchip
► Motorola
Criteria for Selecting microcontroller
►   meeting the computing needs of the task
    efficiently and cost effectively
     speed, the amount of ROM and RAM, the
      number of I/O ports and timers, size,
      packaging, power consumption
     easy to upgrade
     cost per unit
►   availability of software development tools
     assemblers, debuggers, C compilers, emulator,
      simulator, technical support
►   wide availability and reliable sources of the
    microcontrollers.
Different aspects of a microcontroller


► Hardware:   Interface to the real world




► Software:   order how to deal with inputs
Test case:                   8051

►   A smaller computer
►   On-chip RAM, ROM, I/O ports...




CPU     RAM ROM
                               A single chip
             Serial
I/O    Timer COM
Port
             Port
             History of 8051
► 1981, Intel MCS-51
► The 8051 became popular after Intel
  allowed other manufacturers to make and
  market an flavor of the 8051.
   different speed, amount of on-chip ROM
   code-compatible with the original 8051
   form a 8051 family
                      Block Diagram
External interrupts
                      On-chip
                                                   Timer/Counter
                      ROM for
     Interrupt        program         On-chip      Timer 1         Counter
      Control         code            RAM                          Inputs
                                                   Timer 0

       CPU


                        Bus                          Serial
                                     4 I/O Ports
       OSC             Control                       Port


                                    P0 P2 P1 P3     TxD RxD
                                 Address/Data
Pin Description of the 8051
        P1.0   1             40   Vcc
        P1.1   2             39   P0.0(AD0)
        P1.2   3             38   P0.1(AD1)
        P1.3
        P1.4
               4
               5
                     8051    37
                             36
                                  P0.2(AD2)
                                  P0.3(AD3)
        P1.5   6    (8031)   35   P0.4(AD4)
        P1.6   7             34   P0.5(AD5)
        P1.7   8             33   P0.6(AD6)
        RST    9             32   P0.7(AD7)
(RXD)P3.0      10            31   EA/VPP
 (TXD)P3.1     11            30   ALE/PROG
(INT0)P3.2     12            29   PSEN
(INT1)P3.3     13            28   P2.7(A15)
    (T0)P3.4   14            27   P2.6(A14)
    (T1)P3.5   15            26   P2.5(A13)
  (WR)P3.6     16            25   P2.4(A12)
   (RD)P3.7    17            24   P2.3(A11)
      XTAL2    18            23   P2.2(A10)
      XTAL1    19            22   P2.1(A9)
        GND    20            21   P2.0(A8)
Port 3 Alternate Functions
 P3 Bit   Function   Pin

 P3.0     RxD        10
 P3.1     TxD        11
 P3.2     INT0       12
 P3.3     INT1       13
 P3.4     T0         14
 P3.5     T1         15
 P3.6     WR         16
 P3.7     RD         17
          MICROCONTROLLER I/O pins


I/O pins are very useful for the following :
► reading Inputs/ reading keypads
► Displaying output
► controlling Motors (PWM) etc.
                 A Pin of Port 1

 Read latch                       Vcc
                          TB2
                                        Load(L1)


Internal CPU        D     Q                          P1.X
     bus             P1.X                             pin

Write to latch      Clk   Q             M1




                            TB1
  Read pin                                         P0.x
                                  8051 IC
      Writing “1” to Output Pin P1.X
                                              Setb p1.x


       Read latch                                    Vcc
                                TB2
                                                           Load(L1) 2. output pin is
1. write a 1 to the pin                                                   Vcc
     Internal CPU         D     Q
                                      1                                   P1.X
          bus              P1.X                                            pin
                                          0                M1
                                                                       output 1
     Write to latch       Clk   Q




                                    TB1
        Read pin

                                                     8051 IC
      Writing “0” to Output Pin P1.X

       Read latch                             Vcc
                                TB2
                                                    Load(L1) 2. output pin is
1. write a 0 to the pin                                           ground
     Internal CPU         D     Q
                                      0                            P1.X
          bus              P1.X                                     pin
                                          1         M1
                                                                output 0
     Write to latch       Clk   Q




                                    TB1
        Read pin

                                              8051 IC
               Reading “High” at Input Pin

        Read latch                                Vcc                2. MOV A,P1
                                        TB2                         external pin=High
                                                         Load(L1)

                                              1                1        P1.X pin
     Internal CPU bus        D      Q
                                 P1.X
                                              0         M1
       Write to latch        Clk    Q




                                        TB1
          Read pin
3. Read pin=1 Read latch=0
      Write to latch=1
                                                    8051 IC
               Reading “Low” at Input Pin

        Read latch                                    Vcc                2. MOV A,P1
                                        TB2
                                                             Load(L1)   external pin=Low


                                              0                    0        P1.X pin
     Internal CPU bus        D      Q
                                 P1.X

       Write to latch        Clk    Q             1         M1




                                        TB1
          Read pin
3. Read pin=1 Read latch=0
      Write to latch=1
                                                        8051 IC
                8051 Family
► Mask   programmable
   factory fitted Programs
► OTP   one time programmable
   User Programmable
► Reprogrammable
   User Reprogrammable
       Comparison of the 8051 Family Members
►   ROM type
      8031 no ROM ; requires external Rom
      80xx mask ROM
      87xx EPROM
      89xx Flash EEPROM
►   89xx
      8951
      8952
      8953
      8955
      898252
      891051
      892051
►   Example (AT89C51,AT89LV51)
      AT= ATMEL(Manufacture)
      C = CMOS technology
      LV= Low Power(3.0v)
               Registers

       A

       B

       R0
                    DPTR          DPH                  DPL
       R1

       R2             PC                    PC
       R3

       R4                  Some 8051 16-bit Register

       R5

       R6

       R7

Some 8-bitt Registers of
       the 8051
      Memory mapping in 8051

►   ROM memory map in 8051 family
RAM memory space allocation in the 8051


            7FH


                                    General RAM


            30H

            2FH
                                Bit-Addressable RAM

            20H
            1FH                    Register Bank 3
            18H
            17H
                                  Register Bank 2
            10H
            0FH                   Register Bank 1
            08H
            07H
                                  Register Bank 0
            00H
Development Cycle of microcontroller based project
      How to interface Devices
► Inputs and Outputs
► Compatibility of I/Os
► Impedance matching
► Selecting right microcontroller
      General diagram of Automation
Sensor
input/Analog                                 Set point


                                   D0~D7

                                                         Display


                  Analog to
                                              8051uc
               Digital converter


                                                         Actuator


                                   Control
                                   Signals
               Why Microcontroller
Less complex
Cheaper

Example

   Thousands    hundreds     Tens       Units




   Decoder      Decoder     Decoder   Decoder




   Counter      Counter     Counter    Counter


                                      Clk input
                                 Controller
►Fixed
►Universal controllers



Universal controllers
► Inputin form of 0 ~5v
► 4 ~ 20mA
► 0 ~20mA



Conversion using Transmitter
Exp. Temperature transmitter, pressure transmitter. etc
 Applications of microcontroller
► Personal  information products: Cell phone,
  pager, watch, pocket recorder, calculator
► Laptop components: mouse, keyboard,
  modem, fax card, sound card, battery
  charger
► Home appliances: door lock, alarm clock,
  thermostat, air conditioner, TV remote, VCR,
  small refrigerator, exercise equipment,
  washer/dryer, microwave oven
► Industrial equipment: Temperature/pressure
  controllers, Counters, timers, RPM Controllers
► Toys: video games, cars, dolls, etc.
Microcontroller Applications
Microcontroller Application Area
Sample projects
 Car parking gate control
                   Car parking gate control program

            org          0
            mov p0, #00
            mov p1, #00
            mov p2, #00
            mov p3, #00
wait:       jnb p1.0, wait1    ; wait for enter into parking
            acall here         ; if inside goto here subroutine
wait1:      jnb p1.2, wait     ; wait for leave parking
            acall here1        ; if leave parking goto here1
here:       setb p2.0          ; start motor1 for open d gate
limit1:     jnb p3.0, limit1   ; start motor1 until it strikes to limit switch
            clr p2.0           ; after defined time stop d motor
switch:     jnb p1.1, switch   ; wait for input when the car cross the entering door
            setb p2.1          ; when gate crossed start motor1 in revese direction to close d gate
limit2:     jnb p3.1, limit2   ; start motor1 in reverse direction until it strikes to the other limit
            clr p2.1           ; after closing the door now stop motor1
            inc a              ; start counter to count number of cars on seven segment display
            mov p0, a          ; display result on port 0 'use decoder'
            ret                ; return from subroutine
here1:      setb p2.2          ; start motor2 for open d gate
limit3:     jnb p3.2, limit3   ; start motor2 until it strikes to the other limit
            clr p2.2           ; after defined time stop d motor
switch1:jnb p1.3, switch1      ;wait for input when the car cross the exit door
            setb p2.3          ; when gate crossed start motor2 in revese direction to close d gate
limit4:     jnb p3.3, limit4   ; start motor2 until it strikes to the other limit
            clr p2.3           ; after closing the door now stop motor2
            dec a              ; count down
            mov p0, a          ; display result on port 0
            sjmp wait          ; restart
            end

				
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