PreenFM > preenfm2 and preenfm3

waveforms

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matrix12x:

--- Quote from: Xavier on June 09, 2014, 10:55:04 AM ---
No there's no python script.. What i do is i create directly the c arrays in java based on some series of sinusoid.
I'm afraid you'll have to find by yourself how to create your own arrays.

The waveforms are in the fast memory access of the STM32F4 (CCM). There's only 64Kb here and almost all is used.
So what you can do is to replace an existing waveforms (keep the sinusoid one for FM ;-).

Or you can add one or two in the regular memory... just remove the "__attribute__ ((section(".ccm")))" in the declaration in the wave.c file..
Will be slower and could produce some audio glitch when access in full polyphony with effects...

Xavier

--- End quote ---

Thanks. I have my table now, normalized to +/-1. 1024 values. I am adding them to waves.c, but I have one quick question, do I need to format in 5 rows of equal size like you did? For my first attempt, I am going to load it into regular memory, and see what happens.

matrix12x:
Quick question, what is the tool chain that is required?
I am on OSX.

pld:
I've been using gcc-arm-none-eabi-4_7-2013q3 on OS X.
IIRC I did a 'brew install dfu-util' to be able to flash the board directly...

pld:

--- Quote from: matrix12x on June 10, 2014, 12:44:18 AM ---do I need to format in 5 rows of equal size like you did?

--- End quote ---
As long as the array has 1024 elements, the formatting shouldn't matter. But it is more readable in case have to re-count :)
How did you come up with the values?


--- Quote ---For my first attempt, I am going to load it into regular memory, and see what happens.

--- End quote ---
Will be interesting.
If I find some time, I'll compile a debug version and measure the impact in cycles (unless Xavier has already tried that?).

Xavier:

--- Quote from: pld on June 10, 2014, 11:10:28 AM ---
--- Quote ---For my first attempt, I am going to load it into regular memory, and see what happens.

--- End quote ---
Will be interesting.
If I find some time, I'll compile a debug version and measure the impact in cycles (unless Xavier has already tried that?).

--- End quote ---

The only measure i did (a while back) was that with regular memory i could not get 8 voices (of 6op) at the same time without audio drop out.
Since then, there were a lot of optimization (and i could even add a FX slot).
Don't know what the status is today.
Would be fast to test ;-)
remove "__attribute__ ((section(".ccm")))" from all wavetables and try to get audio glitch.

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