Touchless computer interfaces

A touchless user interface comprising:

• a first sensor, comprising a first light emitting diode and a first photodiode;
• a first sensor signal conditioning unit coupled to the first sensor and configured to raise a first sensor output signal HIGH when the first photodiode detects a light pulse of sufficient intensity emitted by the first light emitting diode and reflected off an object;
• a switch;
• a microcontroller comprising a timer, coupled to the first sensor signal conditioning unit and the switch, wherein the microcontroller comprises programmable logic to perform the following operations:
• when the first sensor output signal is HIGH, begin the timer;
• when a pre-specified amount of time has elapsed as indicated by the timer, set the switch to an ON configuration.