FREQOUT command

[Art]

Hi Guys,
I’m FREQING OUT about the FREQOUT command!
No I’m not, but wondering how it works. I assume the command must add sine tables to the program,
and already sum each frequency and divide by two before doing anything with PWM in order to get
the mix of both frequencies out of a single pin?

Anyway, I’m not finished, and also improved the sound by mixing a higher than audible frequency with solitary notes.
This removes the “flutter” distortion heard in this video, and the result is instead something easier to filter.
but just an experiment to share, it’s playing through a MAX232 chip:



There’s a third channel ready to go.. the hardware PWM.

[Art]

Ok,
Unfortunately the thing should have been driven by a timed interrupt
to generate a spot on time signature.
So it sux that to go any further this verbose program has to be disposable :O
It’s still possible to do a drummer (with brushes).

[Jerson]

You possibly have already run into this website. Just in case...
http://www.pic24.ru/doku.php/en/osa/ref/intro

[Art]

I have no luck with the link there Jerson.. tried a couple of days now.

[Jerson]

I can access the link quite well from my side of the world. The following link would be interesting to you in particular. It is a Piano with touch keys done using the PIC_OSA (RTOS) using a PIC and wave tables. I suggest you try bending your access with a proxy server if you still find it hard to reach.
http://www.pic24.ru/doku.php/en/osa/.../pk2_osa_piano