Groove sound sensor: offset problem

Grove is a modulated, ready-to-use tool set.
Much like Lego, it takes a building block approach to assembling electronics.

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vinz
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Groove sound sensor: offset problem

Post by vinz » Tue May 01, 2012 9:38 pm

Hi! I just got this sound sensor (version 1.1) of the groove platform.

Differently from what it has been said in an answer, the silence value is around 0 and not 512.
Hi! I connected this module with my arduino, but the serial-monitor deliveres at silence values like this: 4,16,11,58,107,0,4,33,38. Values at loud music are not very different. Tried to adjust the gain, but it didn´t help... Any suggestions? thx

The sound circuit uses a LM386 amplifier. The amplifier biases the output to half the max output voltage which is 2.5 The sound circuit will always put out 2.5 volts during silence which is around 512 on the analog read. Check out the following link http://lowvoltage.wordpress.com/2011/04 ... amplifier/
This means that a sinusoidal waveform (for example, a sinusoidal waveform of 1 kHz) has an average value of 0, which means that negative values are sampled as 0. This fact avoid me to compute the power of a signal.

Tuning the potentiometer only change the gain, but not the offset.

Is there any way to fix the problem?

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deray
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Re: Groove sound sensor: offset problem

Post by deray » Mon May 07, 2012 10:18 am

what you want to offset? It's correct that the silence value is around 0 .You can visit our wiki before you used your sound sensor.
http://www.seeedstudio.com/wiki/Grove_-_Sound_Sensor

regards,
deray

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