May 27, 2015

Simple passive mono/stereo to stereo audio mixer circuit



A while ago I needed a very simple pasive miker to join one stereo and two mono signals together before amplifying them...

There is some mixed information on how to properly connect a mono signal to a stereo input, but most of it uses active mixing.

May 24, 2015

Repair faulty HC-SR04 ultrasonic sensor (solve erratic no-readings problems)

Recently I got some of these cheap sensors from Chinese suppliers, for a workshop I had to teach.
A couple of students reported that their sensors were behaving in an erratic way, sometimes working, then stopping again, the working...
After replacing them with more expensive ones bought at a local store, I decided to try fixing the faulty ones...

Feb 17, 2015

Sep 27, 2014

Arduvision (I): embedded computer vision with arduino

Ok, its time to share stuff again.
I've spent most of this year's (2014) summer learning how to use a CMOS sensor together with an arduino (ATmega328p) microcontroller, in the process of developing some personal projects.
This is the first of a series of articles to publish my experiencies, and hopefully save someone's time.

In this first post, I'll just release the minimal info that may let you start right away experimenting without reading about how things work. In further articles I'll make detailed explanations of the hardware and software, and the decisions and reasons that led me to my current setup. However, at the end of this post, you may find links to useful documentation.

Apr 5, 2014

How I solved my SD card corruption problems by modding the Raspberry Pi

I've spent last month struggling (once again, after some trouble with the power) with SD card corruptions due to the Raspberry Pi's "design idiosyncrasy" (a funny name to avoid cursing).
Until I finally found a solution... 



Feb 18, 2014

Impress Progress Bar



A few months ago I wanted to have a progress bar in an Impress presentation, but couldn't find a feature to generate it automatically. So I had to write a macro script... 

Feb 4, 2014

Playing with the 3D printer & microfusion metal casting

Today I collected my first microfused things from Fundiart, in  Valencia.
The items were printed in PLA and cast in brass, and the results are excellent.
Continue reading to see a video and some pictures...