[sdiy] newbie question Can a simple PIC16F628A be usedasan audio filter trigger like a light organ

[Richie Burnett]

A 16 series PIC is under-powered for full-bandwidth audio signal processing 
because of the lack of hardware multiply, but you should definitely be able 
to get an 18 series PIC to run a few instances of the Goertzel algorithm and 
detect the presence of different frequencies:

https://en.wikipedia.org/wiki/Goertzel_algorithm

Goertzel is often used to detect the presence of DTMF ("touch tones") on 
relatively primitive microcontrollers.

-Richie,


On 24 Feb 2016, at 05:33, Rob <roomberg at ptd.net> wrote:

> I'm an electronic hobbyist. Nothing professional.... just playing here.
> The goal is to feed MP3 music to a light trigger circuit.
> Something like a light organ.
> But have a much finer granularity than a light organ that has low, mid and
highs separation.
> I have PIC16F628A chips and PicBasicPro so I was thinking of using PULSIN
to look for audio tones... real high stuff... around 6kHz ,7kHz and 8kHz.
>
> I had been building audio band bass filters with op-amps when it occurred
to me that PicBasic WILL listen for tones and assign a value to a variable.
But I had not seen anything that resembled this circuit before.