Covox

[bill]

Hello, i had an idea, that is probably stupid, but i wanted to tell you :

It's about generating sounds (digital waveforms) thanks to MIOS.

I allready read somewhere on the ucappps website, on maybe it was on this forum that it's possible to generate sounds, but i cant remember the way it's working.

You probably know the good old covox 'soundcards'

http://en.wikipedia.org/wiki/Covox

Dont you think it could be very funny to generate 8bit waveforms thanks to this, and a DOUT module ? (but maybe it's not fast enough ?)

It could be possible to store loads of 8bit (even 4bit !!) waveforms inside a pic, or even to write algorithm for sound generation  ::)

So, what do you think ?

[bill]

Stupid me, :-[

http://ucapps.de/mios/analog_toolbox_v1_1c.zip do it better ...

Can someone explain me what the analog toolbox do ? (i dont have a AOUT interface to try it)

[Jaicen]

It's possible for the PIC to generate tones itself, be they square waves or otherwise. Is this what you're getting at??

Have you seen the AVR synth? I think that's pretty close to what you're imagining.

http://www.elby-designs.com/avrsynth/avrsyn-about.htm

[bill]

Is this what you're getting at??

Yep, that was the idea, i guess a pic can do it, but what about mios ?

then what do you think about the covox dac ?

(maybe it's too shitty, and a real dac do the job better, for quite the same price)

[mess]

Hi Bill

Stupid me, :-[

http://ucapps.de/mios/analog_toolbox_v1_1c.zip do it better ...

Can someone explain me what the analog toolbox do ? (i dont have a AOUT interface to try it)

The analog toolbox is made to generate analog control voltages

for modular synth modules (like analog filters, voltages...)

it stores a 8 bit sine wavetable for converting a saw->sine (see map.c)

About that Covox DAC, have you seen:

http://www.ucapps.de/mbhp_aout_lc.html

What do you think of a avrsyn for sound generation

and a mios engine for modulation, presets,control surface...

:D

bye,

Michaël

[bill]

What do you think of a avrsyn for sound generation

and a mios engine for modulation, presets,control surface...

Well, it could be a cool project, but that's not the kind of stuff i'm looking after, but maybe avrsyn can be a good base to start from, if it's open source.

I'd like to do a 4bit waveform generator (like the gameboy wave channel)

That produce a very typical sound, that i love so much !! (amigaish sounding ;)

[mess]

I'd like to do a 4bit waveform generator (like the gameboy wave channel)

I think that all the code for this is allready in the analog toolbox code,

it uses the same waveform generation technique as the avrsyn

only avrsyn is written in asm and it has a 24bit fasor (better frequency resolution)

right now the analog toolbox lfo is updated each millisecond

so max output frequency is 1000/2 = 500Hz

don't know how high you could set the update freq  ???

 

// initialize the timer - it should be invoked each mS

  MIOS_TIMER_Init(0, 10000); // 1 mS / 100 nS = 10000 cycles

so suppose the highest note you need is 2kHz, you will need 4kHz

-> 1/4000 = 0.25mS

-> 0.25mS/100nS = 2500 cycles

-> MIOS_TIMER_Init(0,2500);

do you think this is correct?

That produce a very typical sound, that i love so much !! (amigaish sounding ;)

Do you have an example of that sound?

I'm too young to know how an amiga sounds  :)

[bill]

Amigaish waveforms that i'm talking about can be heard in that lo-bat tune : http://www.lo-bat.be/muziek/good_morning.mp3

Software is musicline, a dynamic softsynth/tracker on the amiga. http://www.musicline.org/

For the gameboy, listen to this tune http://sidabitball.free.fr//NewSlip.mp3

At 1'00, the bass sound is the 4bit wav, then it change to a kind of distorted guitar ;)

Atm, it's just an idea and i'm just not sure it's possible, but i cant stop to think about it  :P

[mess]

thanks for the example, nice bit of lofi crunch  :)

I'm going to try this as soon as my seq is finished...