Patent ID: 8427450

Claim:
A system for sensing and indicating actuation of a capacitive touch sensor, said system comprising: a sampling capacitor having a first terminal connected to a reference potential and a second terminal; an analog-to-digital converter (ADC) connected to the second terminal of the sampling capacitor, the ADC converting an analog voltage on the sampling capacitor to a digital representation thereof; a digital processor coupled to a digital output of the ADC; a capacitive touch sensor having a first terminal connected to the sampling capacitor through a sampling switch and through a port switch with the reference potential and having a second terminal; a pulse generator coupled to the second terminal of the capacitive touch sensor, and a light emitting diode (LED) coupled in parallel with the capacitive touch sensor wherein the LED is turned on by the pulse generator when the port switch completes a current path through the LED; wherein when no object is in proximity to the capacitive touch sensor, a single voltage pulse from the pulse generator and through the capacitive touch sensor charges the sampling capacitor to a first voltage in proportion to a capacitance ratio of said capacitive touch sensor and a capacitance of said sampling capacitor, wherein when an object having a capacitance is within a certain distance to the capacitive touch sensor, some of the voltage pulse through the capacitive touch sensor is diverted from the sampling capacitor, wherein the sampling capacitor is charged to a second voltage when the object is within said certain distance to the capacitive touch sensor, were the second voltage is less than the first voltage, and wherein the capacitive touch sensor and the LED use common connections.