ABSTRACT
Sensors provide with a means of generating signals that can be used as inputs to electronic circuits. A sensor is a special kind of transducer that is used to generate an input signal to a measurement, instrumentation or control system. Transducers are devices that convert energy in the form of sound, light and heat into an equivalent electrical signal. It may be used both as inputs to electronic circuits and outputs from them. Unfortunately, the simple method of interfacing has a limitation when the state of a switch is being sensed regularly. However, a typical application which is unaffected by the problem is that of using one or more printed circuit boards (PCB) mounted switches to configure a logic system in one of a number of preset modes. In such cases, the switches would be set once only and the software would read the state of the switches and use the values returned to initially configure the system.
