Hey all,
I'm currently working on creating a keypad door lock that I hope to be battery operated. For some reason I decided it would be cool to make a touch activated keypad using the cap sense library found here:
http://playground.arduino.cc//Main/CapacitiveSensor?from=Main.CapSense
It works just fine but I'm running into the issue of current draw that I had been fearing. Just scanning through my loop looking for activated cap sensors makes my Uno run at 50 mA which will kill my batteries right quick. I found this post which gave me hope but it is based around the traditional digital inputs.
http://forum.arduino.cc/index.php?topic=132947.0
If I understand this case properly the arduino is woken up up by an input changing state whereas using the cap sense library the inputs are constantly changing and would require being woken by the "cs_pin1_pin2.capacitiveSensor(X);" command returning above a set value.
I realize I could just add a regular push button that wakes the arduino to begin searching for values but I would prefer to avoid this. Does anyone have any idea if its possible to put the arduino into a sleep from which it can be woken by the cap sense library?