The APDS9960 from Avago Technologies has an integrated IR LED and driver, along with four directional photodiodes that sense reflected IR energy from the LED. It's proximity detection feature allows it to measure the distance an object is from the front of the sensor (up to a few centimeters) with 8 bit resolution.Since there are four IR sensors, you can measure the changes in light reflectance at each of the cardinal locations over time and turn those changes into gestures. Our interface library can detect directional gestures (left to right, right to left, up to down, down to up), but in theory more complicated gestures like zig-zag, clockwise or counterclockwise circle, near to far, etc. could also be detected with additional code.The APDS9960 has a configurable interrupt that can fire when a certain proximity threshold is broken, or when a color sensor breaks a certain threshold.