The document provides information on C programming and microcontrollers. It discusses: 1. The sequence of compilation from preprocessing to linking and the output of each stage. 2. Basic C programming concepts like main(), printf(), scanf(), comments, data types, variables, constants, conditional and loop statements. 3. Microcontroller programming using PIC microcontrollers, including setting pin directions using TRIS registers, reading/writing pin values using PORT registers, and an example flasher program that toggles an LED on and off.

2. Why Programming language?
Introduction to C programming.
C programming for microcontrollers ( Micro C ).
 Flasher program

3. Why Programming language?

4. Programming Language
 Hardware is useless without SW.
Programming language is the alternative of writing instruction in
machine code.
Programming languages are filling the gab between machine and
human languages.
Programming Language
Low Level
Language
High Level
Language

5. Sequence of Programming

6. 1.Preprocessing
 It is the first pass of any C compilation.
 It processes include-files.
 It defines the functions used in programming.
 Any Code contains # is foundeded in preprocessor stage.
This tells the compiler what additional files are needed before
processing the actual program.
 Its output is .I file.
Examples : #include<stdio.h> , #define pi 3.14
Stdio.h is the library or the header file that contains the functions which
are used in the programming.

7. 2.Compiler
 It is the second pass.
 It takes the output of the preprocessor, and the source code, and
generates assembler source code.
 It converts the high level Language into Assembly code.
 Its output is .S file

8. 3. Assembler
It is the third stage of compilation.
 It takes the assembly source code and produces an assembly listing
with offsets.
The assembler output is stored in an object file.
 it converts basic computer instructions into a pattern of bits which
can be easily understood by a computer and the processor can use it
to perform its basic operations .
 This file contains Zeros and Ones.
 Its output is .O or .Obj file.

9. 4. Linker
 It is the final stage of compilation.
 It takes one or more object files or libraries as input and combines
them to produce a single (usually executable) file.
 It links the Object files with the libraries.
 Its Output is .EXE file.

10. Introduction to C programming.

11.  It is a part of every C program.
 The parenthesis after main indicate that main is program building
block called a function.
 C programs contain one or more functions, one of which must be
main.
 Every program in C begins executing at the function main.
main()

12. This is used to display argument list on the monitor.
This an output function.
Examples:
printf (“argument”);
printf (“Hello World !!”);
Note:
n is an escape sequence for NEW LINE.
t is an escape sequence for TAB.
Printf()

13.  This is used to input a single character or sequence of characters from
the keyboard.
 It needs the control string codes to be recognized.
Examples:
scanf (“format control string”, &input list);
scanf(“%d,&x);
Scanf()

14.  Starts with /* and ends with */
 It can be simple //
 Programmers insert comments to document programs and improve
program readability.
 Can be placed anywhere in the program.
 Comments are ignored by the C compiler.
 Every line must has a comment
Comments

15.  There are 4 basic data types in C language:
a) Character (char) : used to hold whole number values and ASCII
characters. (8 bit)
b) Integer (int) : used to hold whole number values. (16 bit)
c) Floating Point (float) : used to hold real numbers. (32 bit)
d) Double Point (double) : used to hold real numbers. (64 bit)
Data Types

16.  Signed
By default all data types are declared as signed. Signed means that the
data type is capable of storing negative values.
 Unsigned
To modify a data type’s behavior so that it can only store positive
values.
Long
This doubles the storage capacity of the data type being used.
E.g. long int x will make the storage capacity of variable x to 4 bytes.
Short
If long data type modifier doubles the size, short on the other hand
reduces the size of the data type to half.
Data Modifiers

17. Constants
 A symbolic constant value can be defined as a preprocessor statement
and used in the program as any other constant value.
Examples :
#define PI 3.14
float x;
x = pi; // text replacement
 Declaring Variable as Constant
The values of some variable may be required to remain constant through-
out the program.
Ex:
const int size = 40

18.  Variables are identifiers that can store changeable value.
 Variables are important since they contain the values needed for
manipulation and evaluation of data.
 Variable names are stored in the computer’s memory.
 All variables must be declared before they may be used.
Examples:
char name;
int x, y,z;
float number;
float n1, n2, sum;
double counter;
Variables

19. Global Variables
Variables that are declared outside a function. They are known
throughout the entire program.
Local Variables
Variables that are declared inside a function. They can only be referenced
inside that function. They are also called “automatic variables”.
Global VS local variable
Global Variables
#include <stdio.h>
int a,b,c, x,y,z;
main()
{
}
function()
{
}
Local Variables
#include <stdio.h>
main()
{
int a,b,c;
}
function()
{
int x,y,z;

20. if (condition1)
{
stmt 1; //Executes if Condition1 is true
}
else if (condition2)
{
stmt 2; //Executes if Condition2 is true
}
else
{
stmt 3; //Executes if both conditions are false
}
Conditional Statements

21. switch(condition)
{
case condition1 :
statement 1 ;
break;
case condition2:
statement 2;
break;
…………..
default :
statement
}
Switch statement

22. Iteration Statements
for ( initial condition;condition expression; increment expression)
{
statements;
}
Example:
for(i=0;i<=5;i++)
{
statements;
{
Endless loop
for( ; ; )
{
statements;
}

23. while (condition)
{
statements;
}
Example:
while(i<20)
{
statements;
}
Endless loop
While(1)
{
statements;
}

24. do {
statements;
}
while(condition)
Example:
do{
statements;
}
while(i<10)
 In While loop the condition is
tested first and then the statements are
executed if the condition turns out to
be true.
 In do while the statements are executed
for the first time and then the conditions
are tested, if the condition turns out to be
true then the statements are
executed again.

25. loop :
statements;
goto loop;
Example:
loop:
i++;
if(i<10)
goto loop;
Loop & goto loop statement
Note:
you can type any other name instead of loop

26. Operators is a symbol that tells the compiler to perform specific
mathematical or logical manipulations.
There are 3 classes of operators in C:
a) Arithmetic Operators
b) Relational & Logical Operators
c) Bitwise Operators
Operators

27.  Arithmetic operators are used to perform arithmetic computations.
+ Addition
- Subtraction
* Multiplication
/ Division
% Modulus Division (MOD)
-- Decrement
++ Increment
Arithmetic Operators

28.  When division (/) is applied to an integer, any remainder is truncated.
 % is only used on integer data type.
 The increment (++) operator adds one to its operand and the
decrement operator (--) subtracts one.
Examples
int x=5;
z = x++;
z=++x;
What number will z , x in the Two conditions ?
1. z=5; x=6 2. z=6; x=6

29. Relational & Logical Operators
A. Relational Operators
> greater than
>= greater than or equal
< less than
<= less than or equal
= = equal
!= not equal
B. Logical Operators
! Not
&& And
|| Or

30. 1. & (and) Any of the operand is 0, the outcome is set to 0.
E.X 0101 & 0011 = 0001
2. | (or) Any bit on the operand is 1, the outcome is 1
E.X 0101 | 0011 = 0111
3.^ (XOR) If exactly one of the operator is 1, the outcome is one.
E.X 0101 & 0011 = 0110
4. ~ (One’s complement). Reverse the state of each bit.
E.X ~ 0011 = 1100
5. >> n (Shift Right). Move all bits in a variable n bits to the right.
E.X( 10011001 >> 2) = (00100110)
6. << n (Shift Left). Move all bits in a variable n bits to the left.
E.X(00100110 << 2) = (10011000)
Bitwise Operators

31. Micro C Programming

32. Micro C programming
 Determination of data direction in micro c :-
 TRISX=Value;
X :- is the port name we want to control it’s pins [A , B , C , D , E]
VALUE :- it has one of two values [0 , 1 ]
zero for make the pin output
one for making the pin input .
 The value may binary or hexadecimal or decimal.
TRISX=0b10110101; //Binary
TRISX.fN = 0 or 1;

33.  Make port B output
Trisb = 0b00000000 ;
 Make pins 1 , 3 , 5 in port B input
Trisb = 0b00101010 ;
Examples
 Make port C input
TRISC = 0b11111111 ;
 Make pins 0 , 3 , 7 in port C
output
Trisb = 0b01110110 ;

34.  Put values from microcontroller pins :-
PORTX = Value ;
 Put 5 volt on all pins of port B
PORTB = 0b11111111 ;
 Put 5 volt on pins 1 , 3 , 5 of
port B and other pins are 0 volt
PORTB = 0b00101010 ;
 Put 0 volt on all pins of port
C.
PORTC = 0b00000000 ;
 Put 5 volt on pins 0 , 2 , 4 of
port C and other pins are 0 volt.
PORTC = 0b00010101 ;

35. TRISX . fN = 0 or 1 ;
 Make the pin 3 on port b as
input
PORTB . f3 = 1 ;
 Make the pin 5 on port c as
output
PORTC . f5 = 0 ;
PORTX .fN =0 or 1;
 Put 5 volt on pin 2 of port C
PORTC . f2 = 1 ;
 Put 0 volt on pin 7 of port B
PORTB . f7 = 0 ;

36. Flasher program
void main()
{
trisb=0; //initialize portb as OUPUT
portb=0; //initialize all portb pins to zero
for ( ; ; ) //endless loop
{
portb=255; // all portb pins to 5volt
delay_ms(1000); // delay with 1 sec
portb=0; // all portb pins to 5volt
delay_ms(1000); // delay with 1 sec
}
// End of program