Gesture detection utilizes four directional photodiodes to sense reflected IR energy (sourced by the integrated LED) to convert physical motion information (i.e. velocity, direc- tion and distance) to a digital information. The architec- ture of the gesture engine features automatic activation (based on Proximity engine results), ambient light sub- traction, cross-talk cancelation, dual 8-bit data convert- ers, power saving inter-conversion delay, 32-dataset FIFO, and interrupt-driven I2C-bus communication. The gesture engine accommodates a wide range of mobile device ges- turing requirements: simple UP-DOWN-RIGHT-LEFT ges- tures or more complex gestures can be accurately sensed. Power consumption and noise are minimized with adjust- able IR LED timing.