I'm using op-amp(LM358), condenser microphone and PCA 10028. My project collect output values of op-amp and broadcast that. But, noise was occurred while it is advertising or broadcasting like below. The below is a screenshot during no advertising or broadcasting. I set up high pass filter with 220nF capacitor and 1M ohm resistor but, there was no effect like below. How can I remove this noise? P.S All of screenshot are captured without noise and I separated ground of op-amp with of PCA10028 using 5 ohm resistor. P.S I only connected VCC and ground to PCA10028.

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adc noise during advertising or broadcasting

JoonDong over 7 years ago

I'm using op-amp(LM358), condenser microphone and PCA 10028.

My project collect output values of op-amp and broadcast that.

But, noise was occurred while it is advertising or broadcasting like below.

image description

The below is a screenshot during no advertising or broadcasting.

image description

I set up high pass filter with 220nF capacitor and 1M ohm resistor but, there was no effect like below.

image description

How can I remove this noise?

P.S All of screenshot are captured without noise and I separated ground of op-amp with of PCA10028 using 5 ohm resistor.

P.S I only connected VCC and ground to PCA10028.