Shawon made a surface level meter that indicates when the surface of an object is not level. He used an SCA610 single-axis accelerometer to take the measurements. A PIC16F684 microcontroller controls the angle indicator LEDs and a buzzer. You can check out the video of his circuit in action below.
A bubble or spirit level meter is a handy tool to find whether a surface is horizontal or vertical. It is often carried by civil engineers, mechanical engineers, surveyors, carpenters, and many other professionals whose work involve precise alignments of horizontal and vertical planes. Original spirit levels had two banana-shaped curved glass vials at each viewing point and were much more complicated to use. Mechanical spirit level meters are still available both in 1D and 2D formats. However at present time their electronic counterparts have also emerged and are even available in modern Android equipped cell phones. It’s from there I got my inspiration to make a very simple digital spirit level. Here’s a demo of such an electronic spirit level made by using a Microchip PIC16F684 micro, a SCA610 accelerometer and a handful of other discrete components.
Via Embedded Lab.