Lab 6: Seven segment display

Posted on by 12 comments

Introduction Seven segment LED displays are often found in clock radios, VCRs, microwave ovens, toys and many other household items. They are primarily used to display decimal numbers but they can also display a few alphabets and other characters. This experiment describes interfacing a seven segment LED display to a PIC16F688 microcontroller. You will make a hexadecimal counter that counts from 0 (00h) to 15 (0Fh) and display the value on the seven segment LED display. Required Theory A seven segment LED display is an special arrangement of 7 LED elements to form a rectangular shape using two vertical segments on each

Read more

Single button code entry for a digital lock

Posted on by Leave a comment

Yes, it has got just one push button to enter the code to unlock the system. The author demonstrates how you can just enter multiple code numbers in sequence from a single button input. If the code entered matches with the preset pass code, a relay is turned on. This project uses a PIC16F628A microcontroller that monitors the user inputs from the single button. You can enter a number 3 by pressing the button 3 times. Every time you enter a number, the microcontroller acknowledges by lighting an LED. When you entered all the code numbers correctly in sequence, the

Read more

Overview of an Embedded System

Posted on by 2 comments

Computer systems are everywhere. They fall into essentially two separate categories. The first and most obvious is that of the desktop computer. This is the machine that first comes in our mind when we talk about computers. Desktop computers are designed to be flexible and to meet a wide range of user needs. The end users can change the functionality of a desktop computer by simply changing the application program. One moment you may be using it as a word processor, the next you as an mp3 player or a game station. The second type of computer is the embedded computer

Read more

A Digital temperature meter using an LM35 temperature sensor

Posted on by 84 comments

Introduction A digital thermometer is a good choice of project for beginners who just stepped in to the world of microcontrollers because it provides an opportunity to learn using sensors to measure the real world signals that are analog in nature. This article describes a similar project based on a PIC16F688 microcontroller and an LM35 temperature sensor. LM35 is an analog sensor that converts the surrounding temperature to a proportional analog voltage. The output from the sensor is connected to one of the ADC channel inputs of the PIC16F688 microcontroller to derive the equivalent temperature value in digital format. The

Read more

Timers and counters

Posted on by 2 comments

Introduction Most microcontrollers are equipped with one or more precision timing systems that can be used to perform a variety of precision timer functions including generating events at specific times, determining the duration between two events, or counting events. Example applications that require generating events include generating an accurate 1 Hz signal in a digital watch, keeping a traffic light green for a specific duration, or communicating bits serially between devices at a specific rate, etc. Theory of operation The main component of such a timing system is a free running binary counter. The counter increments for each incoming timing

Read more
« Older Entries Recent Entries »