Tips and tricks

Miscealenous signal processing

  • Small tutorial on the CIC filters

    CIC filters are very useful in applications where one needs to change the sampling frequency in a big ratio, for instance for decimation (reduction of the sampling rate: oversampled acquisition systems, sigma-delta ADC) or interpolation (DAC). In this tutorial, we will see how to tune the CIC filter parameters as a function of the application contraints (decimation / interpolation ratio, ...).

  • Tutorial on a very simple yet useful filter: the first order IIR filter

    This very simple numerical filter (only one tap!), also known as exponential filter because of its impulse response, is, as its equivalent in the analogic domain (the RC electrical filter), very easy to tune and implement. We will present in this small tutorial how to interpret (smoothing and control point of view) and design intuitively this filter from parameters with physical meaning (time constant or cut-off frequency).

    Moreover, we will compare it to the Kalman filter, and show that, under some conditions, it can be an optimal filter!