The ADXL345 is a 3 Axis Accelerometer which can measure accelerations up to ±16 g. It can communicate using both SPI and I2C interfaces. The ADXL345 is a MEMS device which is made by micro-machining on a silicon substrate. It has very small spring-like structures which can deflect on any acceleration in the X, Y and Z axes. These deflections change the capacitance between the fixed plates and plates attached to these spring-like structures. The change in capacitance is converted to a Voltage reading proportional to the change and hence the acceleration.