PROGRAMMING GUIDE

An a rray is collection of the elements of same type  , but many time we have to store the elements of the different data types.  A structure is a user defined data type in C.    A structure creates a data type that can be used to group items of possibly different types into a single type . Each element of a structure is called a member.It is widely used to store student information, employee information, product information, book information etc. Defining a  structure Structure is defined by using struct statement. struct [ structure tag ] { member definition ; member definition ; ... member definition ; } The  structure tag  is optional and each member definition is a normal variable definition, such as int i; or float f; or any other valid variable definition.

A  pointer  is a variable whose value is the address of another variable, i.e., direct address of the memory location. Concept of pointer Consider the declaration, int i=3; This declaration tells the C compiler to: (a) Reserve space in memory to hold the integer value. (b) Associate the name i with this memory location. (c) Store the value 3 at this location . Here the memory mapping is depicted: We can access the value 3 by either using the variable name i or the address 65524. Since the memory addresses are simply numbers they can be assigned to some other variable. The variable that holds memory address are called pointer variables. A pointer variable is therefore nothing but a variable that contains an address, which is a location of another variable. Value of pointer variable   will be stored in another memory location. Here j is not an ordinary variable like any other integer variable....

Features: Ø       Compatible with MCS-51 Products Ø    4 Kbytes of In-System Reprogrammable Flash Memory. Endurance   1,000    Write/Erase Cycles Ø     Fully Static Operation: 0 Hz to 24 MHz Ø     Three-Level Program Memory Lock Ø     128 x 8-Bit Internal RAM Ø     32 Programmable I/O Lines Ø     Two 16-Bit Timer/Counters Ø     Six Interrupt Sources Ø     Programmable Serial Channel Ø     Low Power Idle and Power Down Modes  Description: The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with  4 Kbytes of Flash Programmable and Erasable Read Only Memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the ...

Liquid crystal display is very commonly used electronic display module and having a wide range of applications such as calculators, laptops, mobile phones etc. 16×2 character lcd display  is  very basic module which is commonly used in electronics devices and projects. It can display 2 li nes of 16 characters . Pinout and Pin Description of 16x2 LCD Module Pin No   Function   Name 1 Ground (0V) Ground 2 Supply voltage; 5V (4.7V – 5.3V)  Vcc 3 Contrast adjustment; through a variable resistor  V EE 4 Selects command register when low; and data register when high Register Select 5 Low to write to the register; High to read from the register Read/write 6 Sends data to data pins when a high to low pulse is given Enable 7 8-bit data pins DB0 8 DB1 9 DB2 10 DB3 11 DB4 12 DB5 13 DB6 14 DB7 15 Backlight V CC  (5V) Led+ 16 Backlight Ground (0V) Led-...