Author Topic: Pulse width modulation (Read 3415 times)

Keoni29 · « **on:** September 24, 2011, 04:34:58 am »

I want to generate custom waveforms from a wavetable so I want to know how exactly can you controll the frequency acurately since pause gives me very low frequencies.
This is the wavetable of a saw for instance:
_ _ __ __ ____ _ ____ ____ ___ __
I really don't know if this is going to work

Builderboy · « **Reply #1 on:** September 24, 2011, 04:37:28 am »

Maybe use a simple for loop for your delay? For loops are pretty fast so it would give you some of the highest control of the possible delay.

Keoni29 · « **Reply #2 on:** September 24, 2011, 04:47:59 am »

Is this okay?

Code: [Select]

Lbl WAVE
.Gbd1WV is the wavetable that consists of 1's and 0's
.r1 is the delay between 
.r2 is the amount of waves
for(C,0,r2
  for(B,0,31
    {Gbd1WV+B}->port
    while 1
      A+1->A
    endif A=r1
  end
end

Builderboy · « **Reply #3 on:** September 24, 2011, 04:52:25 am »

Note that you will have to reset A every itteration, or else once it gets to r1, it the while loop will only execute once after that. You could also decide to set A to r1, and decrement A instead of incrementing it, and use an End!IF A, which would make it slightly faster I believe.

Keoni29 · « **Reply #4 on:** September 24, 2011, 05:11:01 am »

Lolthatsstupid

Changed it:

Code: [Select]

Lbl WAVE
.Gbd1WV is the wavetable that consists of 1's and 0's
.r1 is the delay between 
.r2 is the amount of waves
for(C,0,r2
  for(B,0,31
    {Gbd1WV+B}->port
    r1->A
    while 1
      A-1->A
    end!if A
  end
end

Will this work?

calc84maniac · « **Reply #5 on:** September 24, 2011, 10:10:47 am »

Here's a more optimized version (which will probably allow you to use more precise values for r1)

Code: [Select]

While 1
  GDB1WV
  For(32)
    {->r3}->Port
    r1
    While 1
    End!If -1
    r3+1
  End
End!If r2-1->r2

Edit: Removed an unnecessary store instruction

Keoni29 · « **Reply #6 on:** September 25, 2011, 03:20:34 am »

Next step: Blending sound. The Idea is that the notes blend even if they're 3 "steps long" and another note from the other channel that is just one step long comes in the second step.

Like this:
|1 ||2 ||3 | [A-3] [C-2__________] |1 ||2 ||3 |

How do I tackle this problem?

I made a white noise generator too with pretty awesome results:

Code: [Select]

While 1
  rand^4->Port
  r1
  While 1
  End!If -1
End!If r2-1->r2

Keoni29 · « **Reply #7 on:** September 26, 2011, 01:01:38 pm »

I figured that there has to be a 30% duty cycly within a duty cycle to blend the sounds from 3 channels. Can I blend the sounds acurately?

Author Topic: Pulse width modulation (Read 3415 times)

Keoni29

Pulse width modulation

Builderboy

Re: Pulse width modulation

Keoni29

Re: Pulse width modulation

Builderboy

Re: Pulse width modulation

Keoni29

Re: Pulse width modulation

calc84maniac

Re: Pulse width modulation

Keoni29

Re: Pulse width modulation

Keoni29

Re: Pulse width modulation