Forum comments in chronological order

Anonymous
Fri 4-Sep-2009 09:24

Wonderful article.the explanation is meticulous and elegant. Thank you.

Anonymous
Sat 5-Sep-2009 11:42

Fascinating... it appears that the most popular argument for syntax highlighting is in fact "spell check". Except it isn't usually set up so that my variables, a rather small dictionary by most measures, are properly spell-checked, even in languages where they are declared.

Block folding though (note that a comment block is also a kind of block)... now that's the stuff!

Now a little mind-experiment diversion: screen reader, "audio syntax highlighting".

Anonymous
Mon 7-Sep-2009 12:41

one of the most powerfull projects i've ever seen!

i'm just fooling around with one square wave and a rgb led...

Anonymous
Thu 10-Sep-2009 18:36

You still can use 1 of ATmega's PWM channels instead of R-2R ladder which requies 8 uC pins.

Anonymous
Fri 11-Sep-2009 15:53

Glad to see you are hardcore pro syntax highlighting, reading the "The exceptions" part of your, it easy to see that you are against bad highlighing schemes, but then again who isnt?

lft
Linus Åkesson
Fri 11-Sep-2009 16:00

Hi!

Sure, PWM is a good and simple method for rendering an audio signal. I used it in the Turbulence demo, for example.

However, in this particular case it wouldn't work. The microcontroller is running at 8 MHz, and in order to get 8-bit resolution the PWM timer would have to be counting from 0 to 255. The timer can't be clocked faster than the ATmega88. This means we get a nasty carrier wave at about 31 kHz (with lots of overtones), which has to be filtered out. But the audio is generated at 44100 samples per second, so frequencies up to about 22 kHz should be left alone by the filter. Such a steep low-pass filter (almost no attenuation at 22 kHz, almost complete attenuation at 31 kHz) can't be realized with passive components.

In a situation where the system operates at a higher frequency and pins are scarce I would go for the PWM method.

Anonymous
Sat 12-Sep-2009 14:09

GREAT ARTICLE!!! Read articles and books on Terminal I/O and none as clear as this summary.
Well Done!

Anonymous
Sat 19-Sep-2009 22:36

PLS ...send mi cabel from conektor (volume control )or shem volume control cabel imeil zario@dir.bg

Anonymous
Sun 20-Sep-2009 21:32

Hi Linus!
Again, why didn't you use any cheap DAC and communicate via SPI with it? It's pretty simple method, additionally we get good sound quality. Don't say that we won't have processing power for this, because we would have only to activate 1 peipheral.
PS. I like your music, it looks nice between my chiptunes collection :) Could you tell where did you get all that knowledge?

Anonymous
Sun 20-Sep-2009 22:34

I would so love an .XM or .MOD of this.
Or some clear samples of it, I think this sounds gorgeous.

Apart from your technical genius you're a magnificent composer.
Good work.

Anonymous
Wed 23-Sep-2009 14:26

Thanks for a good article

Anonymous
Fri 25-Sep-2009 21:29

You must have a lot of time on your hands. Fun snippets though, must've been a blast to get working. ;)

lft
Linus Åkesson
Sat 26-Sep-2009 18:55

First, it would be an external IC. Why use two chips when one is enough? Second, I think some lo-fi artifacts are desirable in chiptunes, e.g. any non-linearities (but probably not regular noise and hum). If we want a perfect digital representation, we shouldn't bother with a DAC at all, right? Just sample the pins digitally or run everything in a simulator. But I think we'd lose some of the lo-fi character of the sound.


Thank you! I'm trained in classical piano, and I've listened to a lot of music. I've been composing chiptunes and other tracked music for many years, and improved along the way; some of my earlier tunes are really bad. =)

lft
Linus Åkesson
Sat 26-Sep-2009 19:05

Thank you very much!

If somebody would like to make a .mod or .xm cover, feel free to! For details, have a look at the original song, which is available in the tracker source code archive (in a special format that can be loaded into the tracker).