user1354: Hi we are using Arduino Leonardo with some electric paint and Capacitive Sensor Libraries. We have a lot of variance in our Serial output from our sensors, we believe if we grounded the Arduino we would have more concrete values. 
On the Capacitive Sensor doc, it reveals to use a small capacitor to put on one of the pins. More details!
Another guide somewhere says to wrap the Arduino in plastic and tin foil. These are vague, and we have not landed success when we tried. 
Has anyone had success grounding Arduino Leo? Thank you.

user612: The documentation for that library is recommending that you place a 100 pF capacitor between the sense pin and ground.
However, I personally suspect you will get the best results when the user's presence affects at small mutual capacitance between a sense surface and a ground surface.
One idea could be to have a large ground plane, and on it a smaller insulated "sense" plate.
Another could be to run two parallel traces in a spiral filling a large area
Do take care to secure you wires - they are part of your sensor too, and if they move relative to each other they will alter the baseline.  Any other mobile cables in the vicinity can have the same effect, especially if they contain a ground that can exhibit capacitance to the sense node.

1354: <p>Hi we are using Arduino Leonardo with some electric paint and <a href="http://playground.arduino.cc/Main/CapacitiveSensor?from=Main.CapSense" rel="nofollow">Capacitive Sensor Libraries</a>. We have a lot of variance in our Serial output from our sensors, we believe if we grounded the Arduino we would have more concrete values. </p>

<p>On the Capacitive Sensor doc, it reveals to use a small capacitor to put on one of the pins. More details!
Another guide somewhere says to wrap the Arduino in plastic and tin foil. These are vague, and we have not landed success when we tried. </p>

<p>Has anyone had success grounding Arduino Leo? Thank you.</p>
 612: <p>The documentation for that library is recommending that you place a 100 pF capacitor between the sense pin and ground.</p>

<p>However, I personally suspect you will get the best results when the user's presence affects at small mutual capacitance between a sense surface and a ground surface.</p>

<p>One idea could be to have a large ground plane, and on it a smaller insulated "sense" plate.</p>

<p>Another could be to run two parallel traces in a spiral filling a large area</p>

<p>Do take care to secure you wires - they are part of your sensor too, and if they move relative to each other they will alter the baseline.  Any other mobile cables in the vicinity can have the same effect, especially if they contain a ground that can exhibit capacitance to the sense node.</p>
