The 8255 is a programmable, parallel I/O device simply called PPI.
It can be programmed to transfer data in various modes of I/O.
It provides 24 I/O pins that can be grouped into three 8 bit parallel ports: PORT A, PORT B and PORT C.

Keypads are widely used input devices being used in various electronics and embedded projects. They are used to take inputs in the form of numbers and albhabets, and feed the same into system for further processing. In this tutorial we are going to interface a 4x4 matrix keypad with 8051 microcontroller.

An ATMega32 sound generator code is extremely simple to implement. Almost any GPIO pin can drive a piezo buzzer, and the output quality is fine for producing some beeps. The code shown here is the simplest one I remember using basic physics, and since it does not use PWM it could be implemented on almost any microcontroller.

If you are looking for a beginners guide on “How to start with 8051 Microcontroller”, here in this article I will show you how to work with 8051 microcontroller practically. I am not going into detail of “What is 8051 microcontroller”, or “How to write a c-program” etc., but the scope of this article is to tell about the hardware and software

Seven segment displays are important display units in Electronics and widely used to display numbers from 0 to 9. It can also display some character alphabets like A,B,C,H,F,E etc. In this tutorial, we are going to learn how to interface a segment with 8051 microcontroller. We are using AT89S52 microcontroller.