Step number four is to use the optimal electronic interface. In most product designs, the critical characteristic is force vs. output voltage, which is controlled by the choice of interface electronics. Sample interface solutions are detailed in the FSR Integration Guide, available at the Interlink Electronics website, www.interlinkelectronics.com. Some suggested circuit types for common FSR applications are simple interfaces, as shown in the guide, for FSR pressure or force switches; and a current-to-voltage converter is recommended for dynamic FSR measurements or variable controls. This circuit produces an output voltage that is inversely proportional to FSR resistance. Since the FSR resistance is roughly inversely proportional to applied force, the end result is a direct proportionality between force and voltage; in other words, this circuit gives roughly linear increases in output voltage for increases in applied force. This linearization of the response optimizes the resolution and simplifies data interpretation.