[Eiki] found himself in need of a project for his “simple machines” class. Another project had brought him in contact with some relatively cheap MEMS accelerometers and gyroscopes. He had the idea to create a simple tilt sensor based circuit that would light whatever LED was at the bottom.
He’s using an Analog Devices ADXL202E accelerometer chip to sense tilt and an LM3914 bar-graph driver to light the displays. He’s taking the voltage-proportional-to-accelleration output of the accelerometer, filtering it through a capacitor, then feeding it to the bar-graph driver. It may not be the most technically difficult project, but the result is mesmerizing and elegant.