user82936: I have a very simple touch sensor program that works fine and lights an led to show the sensor works; while hooked up to the computer via usb cable it works fine.  When using a power bank with the same usb cable the board lights up but does not read the touch sensor.  I have tried other cables with the same result.

user14095: This is hard to explain but your problem in not unique. I hope this helps. It is your ground reference. When connected to the computer which is grounded either/or a ground wire or capacitive coupling to earth. Your body is capacitively connected to ground that way and when you touch the switch it is recognized.  To make it work with the battery pack you need to couple to the person touching it. You can do that capacitively by adding a ground plain to your circuit. This can be a conductive plate that will capacitively couple the ground to the atmosphere or any other practical means.

82936: <p>I have a very simple touch sensor program that works fine and lights an led to show the sensor works; while hooked up to the computer via usb cable it works fine.  When using a power bank with the same usb cable the board lights up but does not read the touch sensor.  I have tried other cables with the same result.</p>
 14095: <p>This is hard to explain but your problem in not unique. I hope this helps. It is your ground reference. When connected to the computer which is grounded either/or a ground wire or capacitive coupling to earth. Your body is capacitively connected to ground that way and when you touch the switch it is recognized.  To make it work with the battery pack you need to couple to the person touching it. You can do that capacitively by adding a ground plain to your circuit. This can be a conductive plate that will capacitively couple the ground to the atmosphere or any other practical means.</p>
