LCD interfacing with 8051

For general Purpose most commonly used Character based LCDs are based on Hitachi's HD44780 controller or other which are compatible with HD44580. LCD module have 8-bit data interface and control pins. One can send data as 8-bit or in pair of two 4-bit nibbles.

Character LCD type HD44580 Pin Diagram

To display any character on LCD micro controller has to send its ASCII value to the data bus of LCD.For e.g. to display 'AB' microcontroller has to send two hex bytes 41h and 42h respectively.LCD display used here is having 16x2 size. It means 2 lines each with 16 character.

89S series programmer using parallel port

Here is the simple ISP programmer that uses parallel port to interfaces with computer.

Using this we can program almost all AT89S series microcontrollers. In this the power supply required by the board is obtained from the USB Port of PC, 5V.

Embedded Systems

    An Embedded System is a computer system designed to do one or a few dedicated and/or specific functions. often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer (PC), is designed to be flexible and to meet a wide range of end-user needs. Embedded systems control many devices in common use today.

• Never meant to be traditional, general purpose computers.
• Examples: mobile phones, home multimedia, network appliances, transportation or industrial control..
• Use a general purpose processor (most popular ones: arm, x86, ppc) or even a much simpler microcontroller. 

    Physically, embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants. Complexity varies from low, with a single microcontroller chip, to very high with multiple units, peripherals and networks mounted inside a large chassis or enclosure.