I am somehow new to digital sensors and I have a question concerning the digital output from a BMA180 acceleration sensor. I admit that I couldn’t figure out the answer from the datasheet.
This sensor has built-in digital filters which you may select, however the available sample is updated (by default) every 417 ?S (i.e. 2400 Hz), in low-noise mode. The user can enable an interrupt on this frequency and get results every 417 ?S.
There is another nice feature, called sample-skipping, where you can tie the sample frequency (i.e. the above interrupt) to the double of the selected filter frequency, e.g. if you select a filter of 40 Hz, the interrupt fires at 80 Hz (i.e. every 12.5 ms).
My question is what sample skipping means, and how the digital filter comes into play… does it mean that the sensor, internally, makes ADC conversions at 2400 Hz, applying the filter, and gives you output at 80 Hz, or does it make conversions only at 80 Hz ? And if the latter holds, what is happening to the 40 Hz filter ?
Sorry if this sounds noob, but I am a bit confused and I would really appreciate any help !