Circuit Lake

Electronic Project and Circuit Collection

Digital Level Meter

03/21/2010 Category: AVR, Digital, Measurement, Microcontroller, Project

The purpose of MEMS ( micro-electromechanical systems) accelerometer based digital level meter prototype is to replace the ‘Spirit Level’ commonly used by spirit and Carpenters. The recent advances in MEMS based sensors makes this small sized digital equivalent of the ‘Spirit Level’ possible viable. The project is built around microcontroller AVR ATmega16 and ADXL311 (Accelerometer). While the firmware is developed using WinAVR and GNU GCC C compiler.


The proposed spirit level is to simulate the bubble in a spirit level in operation. To achieve this, It use a LED bar with 7 to 11 LED’s. A 2×16 LCD display is also included so that the actual inclination in degrees can be displayed as a decimal number on the first line of the LCD display. The first line can show the angle in degrees and the second line can provide an extended simulation of the air bubble, explained Sameer Cholayil and Seenath Punnakkal, the project designer.

A spirit level is a tool for determining whether a surface is horizontal. It consists of a transparent tube that is held in a frame. The tube contains alcohol or similar fluid but is not entirely filled, so that it also contains a small air bubble. The position of the bubble within the tube indicates whether the instrument is horizontal. Some spirit level has two tubes at right angles to each other, so that the device indicates a vertical as well as a horizontal position. The plumb line was used to determine vertical position until the 17th or 18th century.