Easy SNMP graphs with QuickMon

Sometimes the only thing you need is to see how is your bandwidth usage, or even another metric, without having to install complex management systems like Zabbix. Or sometimes the only thing you want is to take a look over what changes in the server load when you run that simple batch process you are working on.

Amplificando a saída de áudio do seu computador

Ao utilizar ferramentas de conferência online como o Adobe Connect ou Skype as vezes encontramos algumas pessoas que não tem um bom microfone ou não sabem como configurar corretamente as opções de audio. Isso se torna um pesadelo especialmente quando estou nas minhas salas em grupo da Englishtown, ou pior, quando estamos em uma entrevista de emprego, como eu tive a algumas semanas atrás.

Amplifying your computer audio output

While using online conference applications like Adobe Connect or Skype sometimes we find some people who do not have a good microphone or do not know how to configure the audio options properly. It becomes a nightmare specially when I'm in my group classes at Englishtown or, even worse, when we are in a interview for a job application, as I did a few weeks ago.

Scanning Arduino's I2C Bus

Prototyping I2C circuits is not one of the easiest tasks for Arduino users. Sometimes we are racking our brains trying to make our sketch works without even realizing if the device is working properly or well connected to the bus line. Another bad situation is when we are not sure about device address.

Escaneando o barramento I2C do Arduino

Prototipar circuitos I2c não é uma das tarefas mais fáceis para usuários do Arduino. As vezes estamos quebrando a cabeça tentando fazer nossos programas funcionarem sem ao menos termos certeza se o dispositivo está funcionando corretamente ou devidamente conectado no barramento. Outra situação ruim é quando não temos certeza do endereço do dispositivo.

Voltando ao trabalho

Duas coisas me desencorajaram a continuar blogando. Foram elas:

Getting back to work

Two things had discouraged me from blogging. They were:

Controlando múltiplos botões com somente uma porta analógica do Arduino

As vezes quando precisamos controlar um grupo de botões isso pode tomar a maior parte das portas digitais e limitar a capacidade do dispositivo. Nesses casos em que não temos portas digitais suficientes, uma boa solução é utilizar uma porta analógica para gerenciar uma série de botões e resistores.

Controlling multiple buttons with only one Arduino's analog port

Sometimes when we need to handle a set of buttons it may take most part of digital ports and limit the device capabilities. In these cases that we don't have enough available digital ports, a good solution is to use an analog port to handle a series of buttons and resistors.

Controlando o Arduino com .Net

A última versão da ebl-arduino (r52) trás para os usuários do Arduino uma forma fácil de trocar comandos e dados entre PC e Arduino usando .Net, sendo também fácil de ser portado para outras linguagens e transportes (TCP e assim por diante).

Controlling Arduino with .Net

The lastest ebl-arduino release (r52) brings to Arduino's users an easy way to exchange comands and data between PC and Arduino using .Net, being also easy to port to another languages and transports (TCP and so on).

Event-Based Library for Arduino atualizada para R45!

Novas classes foram adicionadas à Event-Based Library for Arduino na sua revisão 45.

Event-Based Library for Arduino updated to R45!

New classes were added to Event-Based Library for Arduino in your revision 45.

Arduino Volt-Ammeter - Final Part - Printed circuit board

After all job of building the prototype and making the sketch work, it's the time to build the circuit. It's not the objective to explain in detail how to make printed circuit boards, but only a superficial explanation about it, besides, of course, to present the project changes to make it works out of Arduino board.

Arduino Volt-Ammeter - Part 1 - Breadboard

I was looking for a real device project to get out from "blinking leds" of Arduino's tutorials and build a device that could be useful in some way. I always thought confuse to have to use two voltmeters, besides the excess of wires around, I already burnt almost all current scales from my voltmeters, to measure current and voltage simultaneously.

ReadWriteLock in C++ for Windows using Mutex and Event

As well as Java has its ReentrantReadWriteLock, C# has its own ReaderWriterLock. What about a class that implements the concurrency control for read and write operations in C++ for Windows.

STL Allocator with low-fragmentation heap

The STL provides a series of data structure, like std::list or std::vector, known as containers. These containers are capable to change their sizes during application run-time, for that it uses dynamic allocators, or simply allocators. The STL already provides a standard allocator for general use, however it's also possible to write your own allocator to be used with containers. The disadvantage of using the standard allocator is because they uses new/delete, the same as malloc/free, which has performance implications that could not be ignored.

Memory management in Windows applications

Contrary to what a lot of people thinks, an application written in C/C++ does not necessarily have to be faster than one made in Java or C#, because these platforms, since they were already designed to be *slower*, usually already has built-in the best methods for most commons application tasks. Among these methods, one of the most important to highlight is the memory management through heap space.

Event-Based Library for Arduino

After I worked in my first Arduino programs, maybe because I worked for a good time with languages like Java and C#, I have found that is a job a little outdated. Tasks like to handle push of buttons or turn a LED on smoothly through PWM, although of being easy to understand, require a reasonable volume of code to become consistent, especially when is necessary that various components work simultaneously.

Event-Based Library - Biblioteca de eventos para Arduino

Depois de feito meus primeiros programas para o Arduino, talvez por ter trabalhado durante um tempo em linguagens como Java e C#, tenho achado a sua programação um pouco antiquada. Tarefas como gerenciar apertos de botões ou fazer um LED acender suavimente atrávés de PWM, apesar de serem simples de se compreender, requer um volume razoável de código para ficarem consistentes, ainda mais quando é necessário que vários componentes funcionem simultâneamente.