Analog sampling over long lines freezes ARM chip

Zigmund:
The device is simply sensing the contact between the ends of those 6 wires, and tells which two wires are currently touching.

Between six wires and a common ground?
Do you use internal pull up or external resistors. What value?

What sort of wire. Shielded, twisted?

Cable has capacitance too. Cat-6 e.g. is ~55pF/m
Unless you terminate the wire at both ends.

Post a diagram.
Leo..