I am working on building a few bare-bones arduinos a la:http://www.jameco.com/Jameco/workshop/JamecoBuilds/arduinocircuit.html
I have come across this statement in the tutorials I've checked out:
"Pin 20 needs to be connected to power if ADC isn't being used, and if it is, it needs to be connected to power via a low-pass filter. (A low-pass filter is a circuit that lessens noise from the power source)."
Can someone please point me towards the necessary information to add such a low-pass filter to my circuit?
Also, if I'm just interested in using I2C, which uses analog pins 4 and 5, do I need the low-pass? Is I2C using the ADC?
My potential applications of I2C include:
Adafruit's I2C backpack: https://www.adafruit.com/products/1049
Reading an accelerometer: http://www.seeedstudio.com/depot/grove-3axis-accelerometer-p-765.html?cPath=144_146
Thanks very much for any help you can offer!