Systems and methods for touch detection using electric field tomography through resistive sheet

A method comprising:

• generating, by a processor at a first electrode of a number of electrodes, a first drive signal, the number of electrodes electrically coupled to an optically transmissive resistive sheet, the electrodes disposed at an edge of the resistive sheet and spaced apart at predetermined intervals;
• generating, by the processor at a second of the electrodes, a second drive signal, each drive signal having a different frequency;
• measuring an output of at least a third of the electrodes while the first drive signal and the second drive signal are generated at the first of the electrodes and the second of the electrodes, respectively;
• and
• determining, based on the output, a location of a touch input on the resistive sheet.

A non-transitory computer readable medium embodying a computer program, the computer program comprising computer readable program code that when executed causes at least one processing device to:

• generate, at a first electrode of a number of electrodes, a first drive signal, the number of electrodes electrically coupled to an optically transmissive resistive sheet, the electrodes disposed at an edge of the resistive sheet and spaced apart at predetermined intervals;
• generate, at a second of the electrodes, a second drive signal, each drive signal having a different frequency;
• measure an output of at least a third of the electrodes while the first drive signal and the second drive signal are generated at the first of the electrodes and the second of the electrodes, respectively;
• and
• determine, based on the output, a location of a touch input on the resistive sheet.