8.3 Functional Description

The Frequency Hop module is interfaced between the Acquisition module and the rest of the post-processing modules, as shown below.

The Frequency Hop module applies a configurable cyclic frequency hopping algorithm, such that on each measurement cycle a different sampling frequency is used. The module is initialized with predefined frequencies, which are set by cyclic order during the consecutive measurement cycles.

The measured raw signal values from the acquisition module are then passed through “Median filter”. Finally, the filtered value is stored back on the memory for further processing by the post-processing modules.

A number of frequencies provides effective filtering by processing more samples. However, this also increases the buffer size used by the median filter and takes a number of measurement cycles to report filtered value. So, the number of frequencies should be configured based on the RAM memory available.