8051 INTERFACING WITH LED, SWITCH, SSD AND KEYPAD

This is a wrap-up article for interfacing hardware with 8051 microcontroller. It's a combo deal for starters because this time, I have interfaced switches, LEDs, seven-segment-display and keypad all at the same time. I have already talked about them, individually, in my previous articles but for better understanding I think it's important to know how they work together. It will also give you some idea about dividing your code into segments and pieces which ultimately polishes your code writing skills.

8051 KEYPAD INTERFACE

When we talk about input to the microcontroller unit, which may or may not be user input, it's not just ON/OFF switches or Push Buttons. In fact there are different methods for collecting data either from a user or the environment. According to the requirements, you can expect a user to press some button, toggle a switch,  enter a username/password e.t.c. while various types of sensing devices are used to detect changes in the environment which will be discussed in my future posts. Today I am going to briefly introduce you to Keypad interface with the 8051 microcontroller. I have noticed many students having problem with this so I have tried my best to keep it as simple as possible while you will try your best to concentrate and understand it once and for all. 

8051 SWITCH INTERFACE

It is necessary for every system to have proper user interface - which makes it user friendly and easy to operate. For instance, imagine using your computer without the monitor (display), keyboard or mouse? It's not even possible to operate it without these essential components as they help you either in entering data (input) to the PC or seeing the results on screen (output). Similarly, an embedded system (the one involving microcontrollers such as 8051 in our case) also require input/ouput devices to be user friendly. A switch can act as an input device to the microcontroller unit (MCU) and this post is all about interfacing/connecting it to the 8051 MCU.