LED Beat Detector

Archiver

Hello all again,

I had another question that may or may not be related to stamps directly...

How does one go about detecting a beat in music? Any particular
frequency range? Are beat meters basically just going off of the volumes of
the input signal (aka loud pulse must be the beat)? Or is there more
intelligence behind the device?

Anyone seen any schematics for such a meter? I dont really care for a
beat per minute count, just an LED that pulses fairly in time with the beat
of music.

Thanks,
Brad - brad@g...

Archiver

Hi Brad,

In modern music the beat is marked by strong bass drum sounds . In that case a
low pass filter with a very low cutoff frequency will do the job. You can do
that in hardware with a few components or in software (of course in that case
you will need an ADC).
Well, that's just an idea... you could also just base your analysis on the
volume, I don't know exactly what you plan to do.

Nicolas



>>> Brad Stockdale <brad@g...> 09/13/00 12:01PM >>>
Hello all again,

I had another question that may or may not be related to stamps directly...

How does one go about detecting a beat in music? Any particular
frequency range? Are beat meters basically just going off of the volumes of
the input signal (aka loud pulse must be the beat)? Or is there more
intelligence behind the device?

Anyone seen any schematics for such a meter? I dont really care for a
beat per minute count, just an LED that pulses fairly in time with the beat
of music.

Thanks,
Brad - brad@g...

Archiver

--- In basicstamps@egroups.com, "Nicolas Fournel"

<Nicolas.Fournel@f...> wrote:
> Hi Brad,
>
> In modern music the beat is marked by strong bass drum sounds . In
that case a low pass filter with a very low cutoff frequency will do
the job. You can do that in hardware with a few components or in
software (of course in that case you will need an ADC).
> Well, that's just an idea... you could also just base your analysis
on the volume, I don't know exactly what you plan to do.
>
> Nicolas

Nicolas,

Thanks for the pointer! I think I will go the route of using some
hardware to do the job (seems a lot easier than using software, to
me)
I figure I'll use the idea of the low pass filter, then use a
comparator to see if the music peaks over a predefined dB threshold.
That should give me a rough beat meter.

Thanks!
Brad

Archiver

I vaguely recall that there is software that will do beat detection via
the sound card, if that helps at all. A friend of mine is a DJ and
classifies all his music by BPM in a database and then with his laptop he
can call up all the stuff he has that has the same (or close) BPM as what
he has playing...this allows him to change tunes without creating too
abrupt a change in 'beat' for the dancers. Oi! technology...

Duncan