The number of pins is often limited on microcontrollers, and when we have a significant number of outputs to control, we can quickly run out of pins. An easy solution to fix this problem is to use a shift register. In this tutorial we’re going to learn how to use a 74HC595 shift register, to output 8 bits of data with only 3 bits from the PIC.
We learned in the first part of this tutorial how to measure a distance with a HC-SR04 ultrasonic sensor. In this second part, we’ll get rid of the LCD display, and instead show the distance on a custom meter made with LEDs. The idea is to turn colored LEDs ON/OFF depending on how close the car is from the wall.
If you don’t have a reverse backup radar system in your car, or if you park forward in your garage, you probably know this feeling of “am I too close, am I gonna hit the wall??”. Well, in this 2 part tutorial, we’re going to create a simple system to detect how close to the wall your car is.
In this tutorial we’ll learn how to control a LCD display from a PIC microcontroller. LCD displays are one of the most used devices to display information. It allows an electronic system to show text and is easily programmable using a microcontroller. We’ll use a PIC16F88 from Microchip. This tutorial can be used to control any LCD display based on a HD44780 controller. Let’s create a little library to control a LCD display!
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.