Posted: December 23rd, 2011 | Author: win | Filed under: Code, Linux | Tags: audio, MPD, music, opengl | No Comments »
Delta VU is a simple audio visualization tool designed to monitor the audio signal level being output by MPD.
According to their project home page, “Music Player Daemon (MPD) is a flexible, powerful, server-side application for playing music. Through plugins and libraries it can play a variety of sound files while being controlled by its network protocol.” MPD has no visualization capability on its own, but provides access to audio being played using a FIFO buffer mounted in filespace. Delta VU reads this buffer and displays the data as an animated VU-style graph that follows the volume of whatever is being played.
- Nifty VU-style level meter displayed using OpenGL/SDL
- Configurable color schemes
Delta VU has been tested on Debian Linux (32 and 64 bit versions) and is available as source code only.
Click here to go to the Delta VU project page on GitHub.
Posted: December 19th, 2011 | Author: win | Filed under: Linux, Notes | Tags: custom, customize, emacs, MPD, terminal, x | No Comments »
Added the following to ~/.xmodmaprc to swap the functionality of the left control key and the caps-lock key:
! Swap Caps_Lock and Control_L
remove Lock = Caps_Lock
remove Control = Control_L
keysym Control_L = Caps_Lock
keysym Caps_Lock = Control_L
add Lock = Caps_Lock
add Control = Control_L
Load the above with the following command (which I put in my ~/.config/openbox/autostart.sh):
Posted: March 8th, 2011 | Author: win | Filed under: Linux, Tools and Gadgets | Tags: electric vehicle, EV, microcontroller | No Comments »
In my spare time, I’ve been working on an embedded system to provide instrumentation and accessory control (indication lamps, turn signal flashers, head lamp relay control, etc.) for use in hobbyist electric vehicles (EVs). Most of my work so far has been focused on implementation of system logic in a simulation environment (desktop Linux).
I’ve written a few tools that simulate some of the hardware that will be present in the target system. I have pulse generators for system timing and a speedometer sensor, a LCD simulator (simple serial 4×20), and a GTK+ GUI to simulate the relay output state and collect contact input from the user. This system is implemented as C code in anticipation of maintaining a build tree that will cross-compile to a ARMv7 MCU.
In case you were wondering, the vehicle silhouette displayed in the GUI shown above is original artwork I created; it was inspired by a Mazda Miata. It is rendered as batch of hard-coded Cairo API calls.
Click here to go to the EVAC project page on GitHub.
Posted: March 5th, 2011 | Author: win | Filed under: Linux, Tools and Gadgets | No Comments »
I’m no composer, and not much of a musician, but sometimes it’s nice to visualize music, or save an idea expressed as notes. The program Lilypond is available in Linux and allows users to enter musical score in a text file, and produce nice looking PDF files and accompanying MIDI. For a friend, I created a simple test file to demonstrate the input format. The Lilypond web site has a much more comprehensive set of documentation.
Here is a link to the Lilypond source file I created, based on my memory of the original tune.
I ran Lilypond from a terminal in order to generate a PDF and MIDI file from the source file like so:
Using the software MIDI synthesizer timidity, I created a sound file from the resulting MIDI file like so:
timidity -Ov earthangel_test.midi
Here is a link to the sound file in Ogg/Vorbis format, rendered using timidity.
Download earthangel_test.ogg (119K)
And finally, here is a link to the score rendered as a PDF (with a screenshot included below).
Posted: February 20th, 2011 | Author: win | Filed under: Linux, Tools and Gadgets | No Comments »
Here is the color theme I created to use with GNU Emacs (Emacs > vi, btw). It’s based on the Blue Mood theme, which is part of the emacs-color-theme package included with Debian. I decided to name it ‘Turbonium’, because I have to hold in a snicker every time I hear that word. I use Emacs for editing C source code mostly, so this color theme is tailored to that end. Here’s a screen shot to demonstrate how it looks with the White Rabbit font by Matthew Welch: