I have a circuit running with capacitive Sensors, that also has an LED strip. everything works fine when using USB power from a laptop (connected to the mains) and 12v 2A adapter powering 1m LED strip.
When the power supply is split and the arduino is also powered from this supply ( using adapter port ) the capacitive sensor begins to give junk values.
What changes in a circuit that would create such a porblem? Could it be a grounding issue? How else to ground this arduino to behave as it would with a usb connection?