As we’ve seen in the previous tutorial, it’s pretty easy to display a single digit number on a seven segment display. If you want to display two digits though, you’ll quickly see it’s a bit more complicated. Today we’ll learn how to multiplex two 7-segment displays in order to display a 2-digit number.
One of the key elements in embedded systems is the user interface. A good user interface will feature visual elements to communicate with the user, such as LEDs or a screen for example. Seven segment displays are widely used in electronic devices, as they can display information in an easy way. We find 7 segment displays everywhere in our homes: our alarm clocks, microwave ovens or even the screens of some devices. Let’s see how to use this component in an embedded system! We’ll start simple, with a single 7 segment display.
When I build a circuit on a breadboard, the first problem I always have is to create the 5V that will power the components. Of course there are a lot of pre-made power-supplies that you fit perfectly on the power rails of the breadboard, but I wanted something that I built myself and I can use with all my circuits. In this article I will present the power supply I came up with, as well as a step by step explanation of the circuit.
So we’ve completed the first part of this tutorial, and are now ready to start doing interesting things. It’s time to build a simple circuit and put some life in it with a program. We’ll start with something very basic, and program our microcontroller to blink a LED blink.
In this series of tutorials we’re going to learn how to create our first embedded program for PIC microcontrollers. They are built by Microchip, and massively used in the industry. There are several other big actors in the world of microcontroller, such as Atmel with their AVR products (although they’ve recently been bought by Microchip), NXP, Freescale and much more. I decided to present Microchip’s microcontrollers because they are one of the most used brand of microcontrollers, and because the tools are easy to set up. They’re also relatively cheap and available on Windows, Mac and Linux, making it accessible to most people.