LCD Control with an MCU

November 17, 20129 comments

Controlling a liquid crystal display (LCD) to indicate a few ASCII characters should not be a big challenge as a project. That’s exactly what I thought when I decided to include a 2 line by 16 character display in my current project. My initial thought was. “How difficult could it be with all the resources on the internet and my embedded development expertise primarily in telecoms?” Let me tell you it is not as straightforward as I thought it would be and therefore I...

How to Build a Fixed-Point PI Controller That Just Works: Part II

March 24, 20122 comments

In Part I we talked about some of the issues around discrete-time proportional-integral (PI) controllers:

• various forms and whether to use the canonical form for z-transforms (don't do it!)
• order of operation in the integral term: whether to scale and then integrate (my recommendation), or integrate and then scale.
• saturation and anti-windup

In this part we'll talk about the issues surrounding fixed-point implementations of PI controllers. First let's recap the conceptual structure...

How to Build a Fixed-Point PI Controller That Just Works: Part I

February 26, 20128 comments

This two-part article explains five tips to make a fixed-point PI controller work well. I am not going to talk about loop tuning -- there are hundreds of articles and books about that; any control-systems course will go over loop tuning enough to help you understand the fundamentals. There will always be some differences for each system you have to control, but the goals are the same: drive the average error to zero, keep the system stable, and maximize performance (keep overshoot and delay...

Embedded Software Creation II - European Normative & Legislation

December 20, 20116 comments

In this post I will explain the European Normative. I will answer the main questions and I will be open to answer all the doubts any of you could have. Please leave a comment and I will answer if i could.

Why I need to look and accomplish some standards?

The main reason is if you want to comercialize the product in the European Union, if exists any European Directive that cover the product, the product must be marked with the CE mark. For USA it work in the same way by the...

C++ on microcontrollers 4 – input pins, and decoding a rotary switch

November 12, 20112 comments

previous parts: 1, 2, 3

This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

So far I...

C++ on microcontrollers 3 – a first shot at an hc595 class with 8 output pins

November 2, 2011

previous parts: 1, 2

This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

In the first part of...

C++ on microcontrollers 2 - LPCXpresso, LPC-link, Code Sourcery, lpc21isp, linkerscript, LPC1114 startup

October 24, 20115 comments

previous parts: 1

This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

I teach my students that...

Using XML to describe embedded devices (and speak to them)

October 12, 20111 comment

This article discusses one of the typical development cycles in embedded device and communication design and presents a possible, light weight solution using the free DClib/netpp framework.

The challenge

Assume we're faced with the design of an embedded device, be it a simple SoC unit or a more complex, uC controlled engine with various attached peripherals. From first prototype to the market, the following development cycle is typically walked through:

C++ on microcontrollers 1 - introduction, and an output pin class

October 9, 20117 comments

This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers.  Reader input is very much appreciated, you might even steer me in the direction you find most interesting.

I am lazy. I am also a programmer. Luckily, being a lazy...

Which MOSFET topology?

September 1, 20119 comments

A recent electronics.StackExchange question brings up a good topic for discussion. Let's say you have a power supply and a 2-wire load you want to be able to switch on and off from the power supply using a MOSFET. How do you choose which circuit topology to choose? You basically have four options, shown below:

From left to right, these are:

High-side switch, N-channel MOSFET High-side switch, P-channel MOSFET Low-side switch, N-channel...

Practical CRCs for Embedded Systems

October 20, 20157 comments

CRCs are a very practical tool for embedded systems: you're likely to need to use one as part of a communications protocol or to verify the integrity of a program image before writing it to flash. But CRCs can be difficult to understand and tricky to implement. The first time I attempted to write CRC code from scratch I failed once. Then twice. Then three times. Eventually I gave up and used an existing library. I consider myself intelligent: I got A's...

How to make a heap profiler

May 23, 20141 comment

We'll see how to make a heap profiler. Example code for this post makes up heapprof, a working 250-line heap profiler for programs using malloc/free.

It works out of the box on Linux (tested on "real" programs like gdb and python). The main point though is being easy to port and modify to suit your needs. The code, build and test scripts are at github.

Why roll your own heap profiler?

• It's easy! And fun, if you're that sort of person. What, not reasons enough? OK, how...

Arduino robotics #2 - chassis, locomotion and power

October 16, 20131 comment
Arduino Robotics

Beginner robotics is a series of article chronicling my first autonomous robot build, Clusterbot.  This build is meant to be affordable, relatively easy and instructive.  The total cost of the build is around $50. 1. Arduino robotics - motor control2. Arduino robotics - chassis, locomotion and power3. Arduino robotics - wiring, coding and a test run4. C++ on microcontrollers 4 – input pins, and decoding a rotary switch November 12, 20112 comments previous parts: 1, 2, 3 This blog series is about the use of C++ for modern microcontrollers. My plan is to show the gradual development of a basic I/O library. I will introduce the object-oriented C++ features that are used step by step, to provide a gentle yet practical introduction into C++ for C programmers. Reader input is very much appreciated, you might even steer me in the direction you find most interesting. So far I... Coding Step 3 - High-Level Requirements August 17, 20152 comments Articles in this series: If this series of articles has been light on one thing it's 'coding'. If it's been light on two things the second is 'embedded'. In three articles I haven't gotten past Hello World on a desktop PC. That changes (slowly) with this article. In this article I'll... Linux Kernel Development - Part 1: Hello Kernel! June 2, 20192 comments Our very first program in every language or framework usually is the notorious "Hello World" program. For this Linux Kernel Modules Development introduction we will follow the same concept, but instead of the usual "Hello World" we will make a "Hello Kernel!" and you will understand the reason in a few moments. Note that in this article I will not focus on a deep explanation about this topic for the moment, since this is only the introduction. But before we dive into code we need to have the... Embedded Programming Video Course Shows How OOP Works Under the Hood September 29, 2019 If you'd like to understand how Object-Oriented Programming (OOP) really works under the hood, here is a free video course for you: OOP part-1: Encapsulation: This first lesson on Object-Oriented Programming (OOP) introduces the concept of Encapsulation, which is the ability to package data and functions together into classes. You'll see how you can emulate Encapsulation in C, what kind of code is generated, and how to debug such code. Next, you will translate the C design into C++ using... Good old multiplexed keypad in an embedded system April 17, 20118 comments Good old multiplexed keypad in embedded systems (My www.embeddedrelated.com Blog No.1) Touch-screens, rotary encoder switches and other navigational aids rule the user interface these days. Navigation through menus and sub-menus is child’s play as icons and thumbnails rule the screen. Jumping from one screen to another, switching between programs and event notification pop-ups are made possible due to high... Arduino robotics #3 - wiring, coding and a test run October 17, 2013 Arduino Robotics Arduino robotics is a series of article chronicling my first autonomous robot build, Clusterbot. This build is meant to be affordable, relatively easy and instructive. The total cost of the build is around$50.

1. Arduino robotics - motor control2. Arduino robotics - chassis, locomotion and power3. Arduino robotics - wiring, coding and a test run4.

Designing Embedded System with FPGA - 1

October 28, 200711 comments

With the introduction of soft processors and related tools (like EDK from Xilinx), implementation of basic embedded system in FPGA is made easy. This requires very little or almost no knowledge of VHDL programming. Actually that’s how I started. If user is interested in taking full advantage of FPGA and its parallel processing power, then yes, detail understanding of soft processor, its peripheral bus and VHDL programming is required.