Just Another Day At Work: Parallel openEMS Simulation

Network of 5 workstations at home, all running Xubuntu

Parametrically sweeping design parameters of a Planar Antenna under simulation. Simulation time is around 5 to 10 minutes per pass, running simulations in parallel drastically cut the time in observing changes in result with respect to different parameter changes.

Acer Aspire 4715z CPU Upgrade

This old laptop has been my Linux workstation on my bedroom for a few months now. It still does the job I require from it - even after 6 years of service - though at times, it already slows down on certain tasks. To speed it up a bit and extend its productive life, I decided to look for a possible processor upgrade. I scoured through eBay and found a used T7700 from China priced at $16.99 including shipping, that's just PHP 772.65 at the time it's bought. The package arrived yesterday afternoon and it's time to see if it will speed up my workstation.

The package includes a thermal compound

A Great Book for Studying the STM32F1 Family of Microcontrollers

I'm bound to learn the STM32 microcontroller, in the shortest possible time, for an ongoing project. While searching for resources and references on the web, I found this book, Discovering the STM32 Microcontroller, written by Geoffrey Brown.

http://www.cs.indiana.edu/~geobrown/book.pdf

The author says the book is written as a hands-on manual for learning the STM32 microcontroller. A quick browse of it shows it is so. The sample projects use actual peripherals that you may have to deal with, including the Wii Nunchuck (for demonstrating the I2C protocol).

For newcomers to the STM32 microcontroller, I think this is a great start. It saves you the time from reading all the technical details in the reference manuals and figuring out how to apply what you've just read from them on your project.

Installing Eclipse (4.4) Luna on Xubuntu 14.04

Xubuntu 14.04 (Ubuntu) still provides Eclipse 3.8 on its repositories. To install the latest release of Eclipse (4.4), the package must be downloaded from Eclipse's website, and extracted manually.

The package can be downloaded here:

http://www.eclipse.org/downloads/

STM32 Flash Loader for Linux

e-Gizmo STM32 MCU Board

I've had this STM32 Board from e-Gizmo for about 2 years now and I think it's about time it gets powered up.

SMath Studio - A Free Mathcad Alternative

While looking for a Mathcad alternative, I stumbled upon one free alternative. It's called SMath Studio and this will come in handy as I'm refreshing my undergraduate Math. This might also be useful to students who doesn't have access to Mathcad (we've had access to it back in college), or professionals who can't afford it.

Here's the URL to it.

http://www.smathstudio.com/ 

Circuits and Electronics - MITx 6.002x

7 years after graduation, I guess it's time to refresh some of my rusted fundamental analog design knowledge. What better way to do that than enroll on MIT's experimental online course, 6.002x - Electronics and Circuits. The course will be running, free of charge, from March 5 to June 8. A certificate is also awaiting at the end of the course.

Here's the URL, by the way.

https://6002x.mitx.mit.edu/

While at it, I am also refreshing most of my Mathematics. It's also a good time to learn about Multivariable Calculus which we never had back in college.

The courses can be found at MIT Open Courseware site. I'm particularly taking the ones designated as OCW Scholar which are deemed more complete than the other Open Courseware available.

Here's the URL to OCW Scholar course.

http://ocw.mit.edu/courses/ocw-scholar/ 

CD4007-Based Voice Changer

Voice Changer (Ring Modulator) based on CD4007

This project is my entry to the 7400 Contest. It's a Voice Changer/Distorter based on a CMOS IC originally intended for digital use, the CD4007 IC. CD4007 contains two Complementary MOS pairs with the third pair connected as an inverter.

Simulation: Single Balanced Modulator

Warming up for a personal project in my virtual lab. This Single Balanced Modulator based on MOS devices will be one part of the project. 

Here are some simulation screenshots before I make the actual circuit.

LTspice Transient Analysis
Circuit under test above plotted trace

LTspice FFT Analysis

Simulation: Headphone Passive Bass Enhance

LTspice simulation

Acer Aspire 4715z Touchpad Repair

Here's another quick video on a repair job on my Acer Aspire 4715z. This time, it's a replacement for the tactile switches on the touchpad (they died during the popularity of Plants vs. Zombies :D).

Acer Aspire 4715z Keyboard Replacement

My Acer Aspire 4715z has served me for 3 years now. Unfortunately, its keyboard is already missing a lot of keys (picked by my daughter Anika when she was one). Typical laptop repair costs around PhP 2000 but I found a replacement keyboard on eBay, and, it only costs approximately PhP 650 (including shipping).