December 17, 2014

SRAM Memories

A Static Random Access Memory, best known as SRAM, is a type of memory that keeps the data stored as long as it's powered, therefore considered a volatile memory. Unlike the DRAM memories, the SRAM doesn't need to be periodically refreshed, which allows for higher access speeds, however they're usually more expensive, consume more power, take up more space and heat more than the DRAM alternative.
Here I'll explain how I designed a small 32 bit SRAM memory (8 rows of 4 bits) for academic purposes. The goal was to design the memory cells and the necessary circuits to its operation, and then to implement the respective layout. The complete circuit was needed to be able to simulate the read and write cycles, while analysing the results.

November 7, 2014

NST Spark Gap Tesla Coil

I remember being attracted by lightning ever since I was a little kid. It always fascinated me staring through a dark and rainy window, during a thunderstorm, watching lightning strike down, lighting up the entire sky while listening to the deafening and imposing sound of thunder. It was quite a show directly from nature, but for me it was more than entertainment, it brought along questions with it, waking up that curious side of me, leading me through my first steps into science: What exactly is it? How does it work? Why does it happen?
How great would it be if you could control that and make it happen anytime you want? So, a few years ago, I learned about Tesla Coils, an air core electrical resonant transformer, invented by Nikola Tesla at the end of the XIX century, able to generate high voltages at high frequencies, resulting in electrical discharges just like small lightning. From that moment I knew I had to build my own Tesla Coil.

September 23, 2014

Lisbon Mini Maker Faire

Last weekend, on the 19th 20th and 21st of September, I had the amazing opportunity to be part of the first Portuguese Maker Faire. It took place in "Pavilhão do Conhecimento" or in english, the Pavilion of Knowledge, in Lisbon and it was visited by over 9000 people, making it mini only in name.
Maker Faire is the greatest show and tell in the world! Originally created by Make magazine, is an event to celebrate arts, crafts, engineering and science projects associated with the Do It Yourself (DIY) movement where the main focus is the sharing of knowledge, experiences and ideas.

September 14, 2014

Node School Event

Recently I was convinced by a friend of mine to go to a Node School Event that he was helping organize. I was always curious about node.js and I've seen pretty interesting applications developed in this platform (and in fairly small amounts of time) so I decided to give it a try.

The event took place on August the 2nd in Faro, Portugal, and it was organized by a local community group called Geek Sessions. They usually organize talks about networking and technology in general. This time they prepared a Node School Event where we were able to learn the basics.

July 5, 2014

New Hardware

I usually don't participate in random internet contests, we all now how annoying they might be and you're lucky if you don't get yourself a new subscription to spam. However I recently tried my luck at a Facebook contest from Texas Instruments Europe, it seemed simple enough and since it's from TI, I knew I could trust it. So imagine my surprise when I found out that I was actually one of the winners!
The prize was an MSP430 BSL Rocket from Olimex, which is basically a programmer for MSP430 microcontrollers with a rocket shaped PCB, a collaboration between TI and Olimex. Unfortunately I haven't had much time to try it yet, but I'm counting on using it soon.

So, thank you TI Europe for this prize, I'll make good use of it!

June 23, 2014

XBee Regulated Adapter Board

Some time ago I came across a project during my Master's Degree that required the use of XBee modules. They are basically 2.4GHz radio modules that make use of the standard IEEE 802.15.4, they are useful for creating low power wireless networks, however their transmission rate is a bit limited.

The thing is that they are quite easy to use and configure but from a prototyping point of view, they are a bit annoying because they don't fit into the breadboard pinout, they have a pin spacing (pitch) of 2mm, instead of the usual 2,54mm, which means you need an adapter. Of course this is not a problem, you can find a lot of them in many stores, cheap too.

June 15, 2014

TDS210 Oscilloscope on LabVIEW over GPIB (IEEE-488)

During my studies, I've done a lot of interesting works, like the calculations for electromagnetic fields on my last post for example, and this is another one. For my Industrial Instrumentation class, I came across this work that had to be done using LabVIEW. The goal was to build a virtual interface for a real instrument that would communicate over GPIB interface (IEEE-488) and that could be used to control and read values remotely.

The work was to be done in groups of 2 and we had the opportunity to choose what instrument we would use. The choice was basically between a TDS210 Oscilloscope and a random multimeter which I don't remember the brand and model anymore.

March 16, 2014

Electromagnetic Fields (EMF) in High Voltage Power Lines

Have you ever wondered about the electromagnetic field around a high voltage power line? Well I have, quite often actually, but I never really found much information about it, at least online. Fortunately, I had to do a work about it, during my academic studies in 2012, it just asked for the EMF values for a constant height but I thought I should make it more interesting by varying the height and making the results a bit more dimensional.

The problem basically gave me the parameters of a specific transmission line and asked for the electromagnetic values at a constant height of 1.8 meters from ground (approximately the height of a person's head), considering that the person could move on the X axis of a transverse section of the power line.

March 12, 2014

Lamp Starter Blinking Lights

This is probably the most simple "project" I've ever tried, it's actually more like a small experiment than a project itself. I wanted an easy way to make light bulbs blink but I didn't want to waste a lot of time making a circuit and I wanted to use whatever I had laying around. So I decided to try a little trick:

I had plenty of fluorescent lamp starters and I thought, if this is a thermal switch, it should give me the blinking random effect that I wanted.

March 9, 2014

Laboratory ATX Power Supply Unit

Now this is a more recent project that I did back in 2012. As I started getting to work on electronics along came the need to have a decent power supply for my experiences, instead of always using different, cheap and weak power adapters. Since I had a few power supply units from old computers laying around, I thought I should modify one to fit my needs. They have a few different voltages available and can be quite powerful.

This was the final result. I wanted it to have a cool high-tech look so I painted the case all black and put some green LEDs inside.

March 5, 2014

Light Switch ON/OFF LED Indicator

When I was first learning electronics I was faced with a little problem. I wanted to have some kind of indicator to tell me if a certain light on a remote location would be ON or OFF. Sure, there are light switches with LED or neon indicators but none of them actually had one for the ON position and another for the OFF position.

I didn't know much yet so I went to talk with a teacher about it. He gave me this circuit for me to try:

March 3, 2014

KITT Voice Box Circuit

So, let me start from the beginning. This, was one of the very first circuits I ever made, back in 2006. As a properly 90's kid, I grew up with some really nice TV influences like MacGyver and Knight Rider, therefore, one of the first things I wanted to do when I started learning about electronics was the KITT voice box.


By this time, I didn't know much yet, I must mention that I didn't even know what a breadboard was. The only thing I did know, was a perfboard, so that's exactly what I used and I must say, it was a headache!

February 27, 2014

So this is how it starts..

Hello world!

As a maker, a hobbyist and an electrical engineer I end up doing a lot of projects. Some are interesting, others not so much, but they all help me learn a few things. But, as these things usually go, often are the times when I'm barely finishing a project and already with my mind on another one, running with excitement over this and that, which is good, but also a bit problematic.