Internship training report

Industrial training report

Dept.of ECE, VJCET 1

CHAPTER 1

INTRODUCTION

1.1 WHAT IS A MICROCONTROLLER?

Basically, a microcontroller is a device which integrates a number of the components of a

microprocessor system onto a single microchip and optimised to interact with the outside world

through on-board interfaces; i.e. it is a little gadget that houses a microprocessor, ROM (Read

Only Memory), RAM (Random Access Memory), I/O (Input Output functions), and various

other specialized circuits all in one package. On the other hand, a microprocessor is normally

optimised to co-ordinate the flow of information between separate memory and peripheral

devices which are located outside itself. Connections to a microprocessor include address,

control and data busses that allow it to select one of its peripherals and send to or retrieve data

from it. Because a microcontrollers processor and peripherals are built on the same silicon, the

devices are self-contained and rarely have any bus structures extending outside their packages.

So a microcontroller incorporates onto the same microchip the following components:

The CPU core

Memory (both ROM and RAM)

Parallel digital I/O

Microcontrollers will also combine other devices such as:

A Timer module to allow the microcontroller to perform tasks for certain time periods.

A serial I/O port to allow data to flow between the microcontroller and other devices such

as a PC or another microcontroller.

An ADC to allow the microcontroller to accept analogue input data for processing.

1.2 WHAT IS AN EMBEDDED SYSTEM?

An embedded system is some combination of computer hardware and software, either

fixed in capability or programmable, that is specifically designed for a particular kind of

application device. Industrial machines, automobiles, medical equipment, cameras, household

appliances, airplanes, vending machines, and toys (as well as the more obvious cellular phone

and PDA) are among the myriad possible hosts of an embedded system. Embedded systems that

are programmable are provided with a programming interface, and embedded systems



programming is a specialized occupation. Also, an embedded system is a special-purpose

computer system designed to perform one or a few dedicated functions, sometimes 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.

1.3 CISC and RISC PROCESSORS

1.3.1 CISC Processors

Complex Instruction Set Computing such as 8051, 8085, x86. More no. of instructions and they

are more complex. The control unit and the instruction decoder occupy most of chip space.

Reduced space for registers.

1.3.2 RISC Processors

Reduced Instruction System Computing such as PIC, Power PC. The number of instructions

is minimized. Addressing modes are fewer. Memory reference instructions are minimized

Processing is register intensive. Each instruction is executed in a single cycle .

1.4 HARVARD AND VON NEUMANN ARCHITECTURES

The Von Neumann architecture is representative of most computer architectures. The most

distinguishing feature of the Von Neumann computer is that it stores both data and instruction

information in the same memory. The Harvard architecture computer stores instructions and data

in separate memory. Many microcontroller architectures are Harvard architectures.

Figure 1.4 VON-NEUMANN AND HARDVARD ARCHITECTURES



CHAPTER 2

MEMORY ORGANISATION

1. Three memory blocks

2. Program memory – 14 bit

3. Data memory – 8 bit

4. Internal EEPROM data memory -8 bit

2.1 CPU REGISTERS

Working register

7 0

Status register

IRP RP1 RP0 TO PD Z DC C/B

7 0

Bank Switching

RP1 RP0 BANK

0 0 BANK0

0 1 BANK1

1 0 BANK2

1 1 BANK3



CHAPTER 3

PIC PIN DIAGRAM AND DESCRIPTION

MCLR-(pin 1) :- PIC16F7X devices have a noise filter in the MCLR Reset path. The

filter will detect and ignore small pulses. It should be noted that a WDT Reset does not drive

MCLR pin low. The behavior of the ESD protection on the MCLR pin has been

a l te red f rom previous devices of th i s fami l y. Vol t ages appl ied to the p in

that exceed its specification can result in both MCLR Resets and excessive

current beyond the device specification during the ESD event. For this reason, Microchip

recommends that the MCLR pin no longer be tied directly to VDD.

RESET :- The PIC16F7X differentiates between various kinds of RESET:

Power-on Reset (POR)

MCLR Reset during normal operation

MCLR Reset during SLEEP

WDT Reset (during normal operation)

WDT Wake-up (during SLEEP)

Brown-out Reset (BOR)

GND –(pin 8) :- Provide Ground to it.

OSC1/CLKIN-(pin 9) :- Oscillator crystal input/external clock source input

OSC2/CLKOUT-(pin 10) :- Oscillator crystal output. Connects to crystal or resonator in Crystal

Figure 3.1 Pin diagram of PIC



CHAPTER 4

INSTRUCTION SET CLASSIFICATION

Single bit manipulations

BCF f,b :- Clear bit b of register f, where b = 0 to 7

BSF f,b :- Set bit b of register f, where b = 0 to 7

Move instructions

MOVLW k w = k (literal value) , where k=0x00,D‟0‟,B‟0000‟

MOVWF f f = w (working reg. to reg.)

MOVF f ,w w = f (reg. to working reg.)

Arithmetic Instructions

ADDLW k w = w + k

ADDWF f ,d d = f + w

SUBLW k w = k -w

SUBWF f ,d d = f – w

INCF f, d d = f + 1

DECF f, d d = f – 1

Logical Instructions

ANDLW k w = w AND k

ANDWF f ,d d = w AND f

IORLWk w = w IOR k

IORWF f ,d d = w IOR f

XORLWk w = w XOR k

XORWF f ,d d = w XOR f

COMF f ,d d = NOT f



Rotate Instructions

RLF f, d rotate F left through the carry bit

RRF f ,d rotate F right through the carry bit

Clear ,Swap

CLRW W = 0(Clear working reg.)

CLRF f f = 0(Clear any reg.)

SWAPF f ,d swap nibbles of f

Conditional branch Instructions

BTFSC f,b Test bit b of register f ,skip if clear

BTFSS f,b Test bit b of register f ,skip if set

DECFSZ f ,d Decrement f ,skip if zero.

INCFSZ f ,d Increment f ,skip if zero.

Branch Instructions

GOTO label Go to labeled instruction

CALL label Call labeled subroutine

RETURN Return from subroutine

RETLW k Return from subroutine ,putting literal value in W.

RETFIE Return from interrupt service routine

Other Instructions

CLRWDT clear watchdog timer

SLEEP go into standby mode

NOP no operation



CHAPTER 5

PORTS

A port is a group of pins on a microcontroller on which the desired combinations of zeros

and ones can be set simultaneously or the present status can be read.

PIC16F73 has 3 ports:- PORTA - 6 bit, PORTB - 8 bit, PORTC - 8 bit

TRIS REGISTERS:-TRIS registers are control registers for ports. TRIS registers are in BANK1.

TRISA control register for PORTA. TRISB control register for PORTB. TRISC control

register for PORTC. If a bit of TRIS Register = 1,corresponding PORT pin will be configured as

inputIf a bit of TRIS Register = 0,corresponding PORT pin will be configured as output.

PORT A :- PORTA is a 6-bit wide bi-directional port. The corresponding data direction

register is TRISA. Setting a TRISA bit (=1) will make the corresponding PORTA, pin an input.

Clearing a TRISA bit (=0) will make the corresponding PORTA pin an output. Multiplexed with

5-channel 8-bit ADC (PA0, PA1, PA2, PA3, PA5).

PORT B :- PORTB is an 8-bit wide, bi-directional port. The corresponding data direction

register is TRISB. Setting a TRISB bit (=1) will make the corresponding PORTB pin an input.

Clearing a TRISB bit (=0) will make the corresponding PORTB pin an output. Three pins of

PORTB are multiplexed with the Low Voltage. Programming function; RB3/PGM, RB6/PGC

and RB7/PGD.Four of PORTB‟s pins, RB7:RB4, have an interrupt onchange feature.RB0/INT is

an external interrupt input pin.Each of the PORTB pins has a weak internal pull-up. A single

control bit can turn on all the pull-ups.

PORT C :- PORTC is an 8-bit wide, bi-directional port.The corresponding data direction

register is TRISC.Setting a TRISC bit (=1) will make the corresponding PORTC pin an

input.Clearing a TRISC bit (=0) will make the corresponding PORTC pin an output.



CHAPTER 6

TIMERS

PIC16F73 has 3 Timers :- TIMER0 - 8 bit, TIMER1 - 16 bit,TIMER2 - 8 bit.

TIMER0 MODULE:- Timer0 operation is controlled through the OPTION_REG register

Timer mode is selected by clearing bit T0CS (OPTION_REG<5>). In Timer mode, the Timer0

module will increment every instruction cycle (without prescaler). If the TMR0 register is

written, the increment is inhibited for the following two instruction cycles. The user can work

around this by writing an adjusted value to the TMR0 register.Counter mode is selected by

setting bit T0CS (OPTION_REG<5>). In Counter mode, Timer0 will increment, either on every

rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0

Source Edge Select bit T0SE (OPTION_REG<4>). Clearing bit T0SE selects the rising edge.

The prescaler is mutually exclusively shared between the Timer0 module and the Watchdog

Timer. The prescaler is not readable or writable.

TIMER1 MODULE:- The Timer1 module is a 16-bit timer/counter consisting of two 8-

bit registers (TMR1H and TMR1L), which are readable and writable. The TMR1 Register pair

(TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR1

Interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit TMR1IF

(PIR1<0>). This interrupt can be enabled/disabled by setting/clearing TMR1 interrupt

enable bit TMR1IE (PIE1<0>). Timer1 can operate in one of two modes: As a timer, As a

counter.The operating mode is determined by the clock select bit, TMR1CS (T1CON<1>).

In Timer mode, Timer1 increments every instruction cycle. In Counter mode, it

increments on every rising edge of the external clock input. Timer1 can be enabled/disabled by

setting/clearing control bit TMR1ON (T1CON<0>). Timer1 also has an internal “RESET input”.

This RESET can be generated by either of the two CCP modules as the special event trigger

.When the Timer1 oscillator is enabled (T1OSCEN is set), the RC1/T1OSI/CCP2 and

RC0/T1OSO/T1CKI pins become inputs. That is, the TRISC<1:0> value is ignored and these

pins read as „0‟.



EXAMPLE : READING A 16-BIT FREE-RUNNING TIMER

MOVF TMR1H, W ; Read high byte

MOVWF TMPH

MOVF TMR1L, W ; Read low byte

MOVWF TMPL


SUBWF TMPH, W ; Sub 1st read with 2nd read

BTFSC STATUS,Z ; Is result = 0

GOTO CONTINUE ; Good 16-bit read


MOVWF TMPH

MOVF TMR1L, W ; Read low byte

MOVWF TMPL ; Re-enable the Interrupt (if required)

CONTINUE ; Continue with your TIMER

TIMER2 MODULE :- Timer2 is an 8-bit timer with a prescaler and a postscaler. It can be

used as the PWM time-base for the PWM mode of the CCP module(s). The TMR2 register is

readable and writable, and is cleared on any device RESET. The input clock (FOSC/4) has a

prescale option of 1:1, 1:4 or 1:16, selected by control bits T2CKPS1:T2CKPS0 (T2CON<1:0>).

The Timer2 module has an 8-bit period register, PR2. Timer2 increments from 00h until

it matches PR2 and then resets to 00h on the next increment cycle. PR2 is a readable and

writable register. The PR2 register is initialized to FFh upon RESET. The match output of TMR2

goes through a 4-bit postscaler (which gives a 1:1 to 1:16 scaling inclusive) to generate a TMR2

interrupt (latched in flag bit. TMR2IF, (PIR1<1>)). Timer2 can be shut-off by clearing control

bit TMR2ON (T2CON<2>) to minimize power consumption.



CHAPTER 7

PIC16F73 INTERRUPTS

Interrupts are mechanisms of a microcontroller which makes it possible to respond to

some events at the moment when they occur, regardless of what microcontroller is doing at the

time.Each interrupt changes the flow of program execution,after executing an interrupt

subprogram (interrupt service routine) it continues from the same point.

GIE PEIE T0IE INTE RBIE T0IF INTF RBIF Table 8.1 INTCON register

RBIF: RB Port Change Interrupt Flag bit

INTF: RB0/INT External Interrupt Flag bit

T0IF: TMR0 Overflow Interrupt Flag bit

RBIE: RB Port Change Interrupt Enable bit

INTE: RB0/INT External Interrupt Enable bit

T0IE: TMR0 Overflow Interrupt Enable bit

PEIE: Peripheral Interrupt Enable bit

GIE: Global Interrupt Enable bit



CHAPTER 8

USART

The Universal Synchronous Asynchronous Receiver Transmitter (USART) module is one

of the two serial I/O modules. (USART is also known as a Serial Communications Interface or

SCI.) The USART can be configured as a full duplex asynchronous system that can

communicate with peripheral devices, such as CRT terminals and personal computers, or it can

be configured as a half duplex synchronous system that can communicate with peripheral

devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc.The USART can be

configured in the following modes: Asynchronous (full duplex), Synchronous - Master (half

duplex), Synchronous - Slave (half duplex).

EXAMPLE : TRANSMITTING „G‟ WITH 9600 BAUD RATE

MOVLW 0X24

BANKSEL TXSTA

MOVWF TXSTA

BANKSEL RCSTA

MOVLW 0X80

MOVWF RCSTA

BANKSEL SPBRG

MOVLW 0X19

MOVWF SPBRG

LAB1:

NOP

BANKSEL TXREG

MOVLW „G‟

MOVWF TXREG



BANKSEL TXSTA

LAB:BTFSS TXSTA,1

GOTO LAB

GOTO LAB1

NOP

END



CHAPTER 9

PIC16F73 ADC

The Analog-to-Digital (A/D) Converter module has five inputs for the 28-pin devices and

eight for the other devices.The analog input charges a sample and hold capacitor. The output of

the sample and hold capacitor is the input into the converter. The converter then generates a

digital result of this analog level via successive approximation. The A/D conversion of the

analog input signal results in a corresponding 10-bit digital number.

The A/D module has four registers.

• A/D Result High Register (ADRESH)

• A/D Result Low Register (ADRESL)

REGISTERS

• A/D Result Low Register (ADRESL)

• A/D Control Register0 (ADCON0)

• A/D Control Register1 (ADCON1)



CHAPTER 10

INTERFACING

(10.1) LCD INTERFACING

Figure 10.1 LCD display

The LCD used in our project is a 16*2 LCD. It can display 16 characters on a single line.

RS (Register Select) Pin :- The Register Select (RS) pin of the LCD is used to select the register

which is to be used to read or write data. A LOW level on this pin will select the instruction

command code register, allowing the user to send command such as clear display, cursor at home

etc. A HIGH on this pin will select the data register allowing the user to send data to be

displayed on the LCD.We also use RS = 0 to check the busy flag bit to see if the LCD is ready to

receive information. The busy flag is D7 and can be read when R/W = 1 and RS = 0, as follows:

if R/W = 1, RS = 0. When D7 = 1(busy flag = 1), the LCD is busy taking care of internal

operations and will not accept any new operation. When D7 = 0, the LCD is ready to receive new

information.

R/W (Read or Write) Pin :- R/W input allows the user to write information to the LCD or read

information from it. R/W = 1 when reading; R/W = 0 when writing.

E (Enable) Pin :- The enable pin is used by the LCD to latch information presented to its data

pins. When data is supplied to data pins, a high-to-low pulse must be applied to this pin in order

for the LCD to latch in the data present at the data pins. This pulse must be a minimum of 450 ns

wide.



D0 – D7 pins :-To display letters and numbers, we send ASCII codes for the letters A – Z, a- z

and numbers 0 – 9 to these pins while making RS = 1. To give commands to the LCD, we send

binary code of the commands to these pins while making RS = 0.

COMMAND CODE(HEX) FUNCTION

0X01 Clear display screens

0X02 Return home

0X04 Decrement cursor (shift cursor to left)

0X06 Increment cursor (shift cursor to right)

0X05 Shift display right

0X07 Shift display left

0X08 Display OFF, cursor OFF

0X0A Display OFF, cursor ON

0X0C Display ON, cursor OFF

0X0E Display ON, cursor blinking OFF

0X0F Display ON, cursor blinking

0X10 Shift cursor position to left

0X14 Shift cursor position to right

0X18 Shift the entire display to the left

0X1C Shift the entire display to the right

0X80 Force cursor to beginning of first line

0xC0 Force cursor to beginning of second line

0X38 2 lines and 5x7 matrix

(10.2) GSM (GLOBAL SYSTEM FOR MOBILE COMMUNICATION) INTERFACING

Figure 10.2 GSM interfacing



Here a GSM mobile hand set is used. GSM networks are originally from the most popular

standard for mobile phones in the world. GSM differs from its predecessors in that both

signaling and speech channels are digital, and thus is considered a second generation (2G)

mobile phone system. This has also meant that data communication was easy to build into the

system. GSM is a cellular network, which means that mobile phones connect to it by searching

for cells in the immediate vicinity. GSM networks operate in a number of different frequency

ranges .Most 2G GSM networks operate in the 900 MHz or 1800 MHz bands. The controller

communicates with the mobile phone by AT comments. The Main AT commands to

communicate via a serial interface with the GSM subsystem of the phone

(10.3) RFID INTERFACING

Radio-frequency identification (RFID) is the use of an object (typically referred to

as an RFID tag) applied to or incorporated into a product, animal, or person for the purpose of

identification and tracking using radio waves. Some tags can be read from several maters away

and beyond the line of sight of the reader.

Figure 10.3 RFID Interfacing

Most RFID tags contain at least two parts. One is integrated circuits for storing and

information, modulating and demodulating a radio frequency (RF) signal, and other specialized

functions. The second is an antenna for receiving and transmitting the signal.

(10.4) KEYBOARD INTERFACING

Keyboards are organized in matrix of rows and coloumns.CPU access both rows and

columns through ports. So an 8X8 keyboard can be connected to a PIC through 2 ports. There



are mainly 2 methods to ckeck the key pressed:- 1.Interrupt method 2.Keyboard scanning

method.By this techniques microcontroller can perform both key press detection & key

identification.

Figure 10.4 Keyboard interfacing



CHAPTER 11

INTRODUCTION TO MPLAB IDE

MPLAB IDE (IDE:-Integrated Development Environment) is a software program that runs on

your PC to provide a development for your embede system design.

Steps :-

Select device

Create project

Select Language tools

Put files in project

Create code

Build project

Test code with Simulator

How to start:-

LIST P=PIC16F73

#INCLUDE “PIC16F73.INC”

CBLOCK 0X20

REGISTERS

ENDC

ORG 00H

PROGRAM

END



CHAPTER 12

CONCLUSION

I would like to say that this training program is an excellent opportunity for me and

experience the things that we would have never gained through going straight into a job. I am

grateful to the entire team of Quest Innovative Solutions, Kochi for giving me this wonderful

opportunity.

As a result of the PIC microcontroller training program, students have been exposed

to engineering applications using embedded applications. These applications enable to

experience the problem solving process and many practical issues that certainly arises in real

world and industrial applications. This training is just a beginning step for student to further

research and develop more complex applications using advance microcontroller such as dsPIC

microcontrollers in the future after their completion of their study.

The main objective of the industrial training is to provide an opportunity to students

to identify, observe and practice how engineering is applicable in the real industry. It is not only

to get experience on technical practices but also to observe management practices and to interact

with fellow workers.



REFERENCES

1. www.wikipaedia.com

2.www.questinnovativesolution.com

3.Muhhammad M.Mazidi ,‟PIC 18 And Embeded C‟,Pearson education

4.www.engineersgarage.com

5.www.microchip.com

6. extremeelectronics.co.in

7. microcontroller.circuitlab.org

http://www.wikipaedia.com/



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