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 LCD INTERFACE

LEDs (lights), interfaced with 8051 microcontroller, can be used to display binary numbers or on/off states while Seven Segment Displays (SSD) can display digits but that's not enough. What if you wanted to display a proper message consisting of numbers, letters, characters, symbols e.t.c.? That's where LCD Screens jump in. LCDs make it convenient to display anything to the user. It may sound tricky to interface an LCD with a microcontroller but trust me or not, it's simpler than it looks and this short tutorial will make sure that you get the hold of it.

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 SEVEN SEGMENT DISPLAY (SSD) INTERFACE

Seven Segment Display which is most commonly known as SSD is an output device which can be used to display information. As discussed in my previous post, it is necessary for a system to have proper input/output devices for assisting the user and SSD serves the very same purpose by displaying some useful information to the user. You can easily connect/interface it with 8051 MCU for output once you understand it properly. After reading this article, you will get to know everything about it. 

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.

HOW TO USE 8051

Simulating and debugging your micro-controller project is fun on a computer using Proteus or similar software but when it comes to practical implementation, it's a bit complicated, or I would say "a headache", to get things done. Its not as simple as mounting the IC on bread board and expecting some output straight away. You have to take care of the "protocols" to achieve your target. You must provide the micro-controller unit (MCU) with proper connections for proper start-up and output.

UPDATE: Visit this link for an updated version of this post - with more details and insight.

8051 INPUT OUTPUT PORTS

The AT89C51 from ATMEL is the most commonly used variation of the 8051 microcontroller because of the built-in Flash which makes programming / burning very easy. The 8051 has a total of 4 ports for input / output operations which means you can transfer data in or out of the microcontroller through these ports. Let's have a brief introduction to these ports.

UPDATE: You can also click this link for an updated version of this post.

8051 PINOUTS

Let's get started. At this point, I assume that you are already familiar with the concept of microcontrollers (specially the 8051) and have some rough idea about the internal architecture because I will avoid going into it. I will just stick to how-to-use tricks for the 8051. However, for a brief introduction, let me highlight the important aspects of it.

UPDATE: You can also click this link for an updated version of this post.