DC offset removal from analog signal

[reva23]

Hi all,


I'm applying analog signal of 60Hz frequency, 2.0Vp-p with 1.0vdc offset using function generator to the arduino analog pin. Im trying to plot FFT for the input signal but my FFT peak is at 0Hz. How can I remove the DC offset from signal in code itself.

Any guidance would be great.

Thanks in advance.

[TheMemberFormerlyKnownAsAWOL]

How can I remove the DC offset from signal in code itself.

Using the subtract operator?

(And please stop just dumping your questions in "Installation and troubleshooting")

[Grumpy_Mike]

How can I remove the DC offset from signal in code itself.

Apply just the offset with no signal on it. Take a measurement, then when sampling simply subtract that measurement from the readings you take.

[DVDdoug]

Or, just make your software ignore the 0Hz bin.

[raschemmel]

@AWOL,
Are you still AWOL ?

"I'm sorry Dave, I can't do that..."

How can I remove the DC offset from signal in code itself.

The brute force approach is an op amp subtractor, but the other suggestions sound like alot less work.

[Vik321]

Code: [Select]

 for(int i=0; i<(SAMPLES/2); i++)
change i to 1 or 2,3 , 5 ......

[6v6gt]

A 1 volt DC offset with a 10bit ADC with a 5 volt voltage reference (e.g. Arduino Uno in standard configuration) implies a shift of 205 analog units.
What sampling frequency are you using ?

[Southpark]

Maybe you can set the component for the FFT result at 0 Hz to be zero. And then IFFT.