Abstract: A touchpad assembly and method for providing a signal to a computer indicative of the location and applied pressure of an object touching the touchpad assembly is provided. The touchpad assembly includes X and Y position and pressure sensitive semiconductor resistance sensor layers. The X and Y sensors have a pair of spaced apart X and Y conductive traces running across opposite ends such that a resistance RX connects the pair of X traces and a resistance RY connects the pair of Y traces. The X and Y sensors come into contact at a contact point when an object asserts a pressure on the touchpad. The contact point is connected to each trace by a variable pressure resistance RZ associated with the X and Y sensors and variable position resistances of the X and Y resistances. First and second pair of timing capacitors are connected to respective ones of the pairs of X and Y traces.

Abstract: Infrared communications scheme for an infrared transmitting device having a light emitting diode (LED) ramps up the power of a carrier frequency signal applied to the LED in a given time interval to a given value. The carrier frequency signal is then frequency modulated with a data message for transmission by the LED. The power of a DC signal applied to the LED may then be ramped up in a given time interval to a given value before the carrier frequency signal is modulated with a data message. After transmission of the data message, the power of the carrier frequency signal applied to the LED is ramped down in a given time interval to a given value. The power of the DC signal applied to the LED is then ramped down in a given time interval to a given value.

Abstract: A touchpad assembly and method for providing a signal to a computer indicative of the location and applied pressure of an object touching the touchpad assembly is provided. The touchpad assembly includes X and Y position and pressure sensitive semiconductor resistance sensor layers. The X and Y sensors have a pair of spaced apart X and Y conductive traces running across opposite ends such that a resistance RX connects the pair of X traces and a resistance RY connects the pair of Y traces. The X and Y sensors come into contact at a contact point when an object asserts a pressure on the touchpad. The contact point is connected to each trace by a variable pressure resistance RZ associated with the X and Y sensors and variable position resistances of the X and Y resistances. First and second pair of timing capacitors are connected to respective ones of the pairs of X and Y traces.

Abstract: Infrared communications scheme for an infrared transmitting device having a light emitting diode (LED) ramps up the power of a carrier frequency signal applied to the LED in a given time interval to a given value. The carrier frequency signal is then frequency modulated with a data message for transmission by the LED. The power of a DC signal applied to the LED may then be ramped up in a given time interval to a given value before the carrier frequency signal is modulated with a data message. After transmission of the data message, the power of the carrier frequency signal applied to the LED is ramped down in a given time interval to a given value. The power of the DC signal applied to the LED is then ramped down in a given time interval to a given value.