Method for controlling operations of input device having resistor matrix

A method for controlling operations of an input device, the input device comprising a resistor matrix having M first traces, N second traces and M×N resistors, first ends of resistors of a same column being connected to one of the M first traces, second ends of resistors of a same row being connected to one of the N second traces, and each second trace being coupled to a reference resistor and M−1 variable resistors, M and N being integers greater than 1, the method comprising:

• measuring a first voltage level of the each second trace when a first voltage is applied to a first end of the reference resistor and a second voltage is applied to first ends of the M−1 variable resistors via the M first traces;
• measuring variations of the first voltage level of the each second trace;
• and
• determining at least one touch point of the input device according to the variations of the first voltage level of the each second trace.