Accelerometer Benchmarks with LIS331AL and ADXL322

The project involves testing of 3-axis accelerometer from ST LIS331AL which will be compared with the DE ACCM2G or ADXL322 accelerometer.

The LIS331AL have been mounted on a break-out board for testing purposes and both accelerometers were connected to the USB Gamepad device and will be using the Gamepad Configuration Software to trace the signals but an oscilloscope could be used instead. An intrinsic noise level will be seen in the first phase of testing the LIS331AL since it will not have any filters. Some vibrations were added to put the device further to the test. This is done by touching the breadboard with an electric toothbrush.

For most applications, the noise needs to be smoothed out by adding capacitors that will create a low pass filter with a cut-off frequency of 50Hz. The noise level will not be reduced by so much since the ACCM2G has an amplifying circuit and different filter values. In conclusion, the filter values should be checked which are suitable for the application when selecting an accelerometer board.

With or without weaker filters, the accelerometer can detect vibration. The filter will be needed when calculating angular data.

Rest of the project