hi,
Im a beginner with arduino and I wanna connect a sensor to adc pin.
I want to use sleep mode adc for noise cancelling but I dont know how?
could you please give me a help?
Start by explaining your second sentence in meaningful terms.
And what sensor do you want to use? Please post a link to its datasheet.
If you already have a program that is not giving you the quality of output that you would like please post it and a sample of its output.
...R
I want to use sleep mode adc for noise cancelling but I dont know how?
For audio? Noise canceling headphones?
I wouldn't try it... The regular Arduino has no built-in DAC, so there is no true analog output unless you add a DAC. The ADC is only 10 bits and not fast enough for "CD quality" audio.
Noise cancelation can be done in analog with a differential amplifier (subtraction amplifier) made with an op-amp.
You also need a preamp for the microphone and a power amp to drive the headphones (or speakers).
It's "easier" with headphones because the headphones are on your ears and the microphones pick-up (almost) exactly the same noise that your ears are hearing. Not easy... easier.
If you are trying to do it with a speaker it can get very tricky... Any distance between the noise source and the speaker putting-out the canceling-sound will create a delay. Delays cause phase shifts and you can end-up adding instead of subtracting (subtracting a negative is the same as adding a positive.)
Have you read the datasheet, page 211, item 23.6?
http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdf