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Topic: Arduino Mega - Equalizer (Read 637 times) previous topic - next topic

nbruxo

Hi Community,

I am fresh in the Arduino world, and I have a project ewhere I need to convert a analog value from -60dB to 6dB into a Led array.

Is the Arduino Mega fast enough to handle this signal or will I have problems with it.

Thank you very much for all your support.

Nuno

Grumpy_Mike

Quote
Is the Arduino Mega fast enough to handle this signal
No idea because you haven told us how fast your signal is changing, nor what exactly you mean by "convert a analog value ... into a Led array.

The statement "-60dB to 6dB" is meaningless because a dB is only a relative measure not an absolute one.

PaulRB

I need to convert a analog value from -60dB to 6dB into a Led array.
That's not what an equaliser does. What you are describing is an LED VU meter.

You don't need an Arduino for this, there is a ready-made chip called LM3915. Each chip can drive 10 leds. Google for circuits using this chip.

nbruxo

Sorry for misusing the words.

You are right what I need to do is to build a VU-meter.

We also found the LM3915 but the teacher insisted that we use a arduino, that is why I asked the question.


Wawa

-60dB to 6dB is an 11-bit range (every 6dB is one bit).
Most Arduinos, including a Mega, have a 10-bit A/D.
Sample frequency might be an issue too.
Both can be 'fixed' with analogue pre-processing.
But that might not be allowed too.
Leo..

PerryBebbington

#5
Jun 12, 2019, 08:29 pm Last Edit: Jun 18, 2019, 04:06 pm by PerryBebbington
Quote
I am fresh in the Arduino world, and I have a project where I need to convert a analogue value from -60dB to 6dB into a Led array.

Is the Arduino Mega fast enough to handle this signal or will I have problems with it.
A friend used to design disco light controllers in the 1990s using PICs, I'm sure he used to do this kind of thing on them. What was available in the 1990s was a lot less powerful that the processor in a Mega, so, is it possible? I very much think so. How? No idea! Has your teacher not taught you enough to do this project?


nbruxo

-60dB to 6dB is an 11-bit range (every 6dB is one bit).
Most Arduinos, including a Mega, have a 10-bit A/D.
Sample frequency might be an issue too.
Both can be 'fixed' with analogue pre-processing.
But that might not be allowed too.
Leo..

Hi Leo that is really precious info
When you mention analogue pre-processing do you suggest any place where I can read about it
Thank you again

Wawa

An LM9315 is made for this sort of thing, and chips can be cascaded to get a larger range.
The datasheet has some nice peak detectors on page 12 and 13.
Leo..

PaulRB

An LM9315 is made for this sort of thing,
Leo, see post #3

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