This library provides an implementation for digital filter cascades, supporting high-pass, low-pass, band-pass, and band-stop filters. It allows initializing, updating, and managing filter cascades for signal processing applications.

• Filter Types: High-pass, Low-pass, Band-pass, and Band-stop.
• Filter Order: Configurable by the user, with a default maximum order of 6.
• Reset and Update: Easily reset and update filter states for real-time processing.
• Configurable Parameters: Set filter type, order, center frequency, bandwidth, and sampling frequency.

• CascadeFilters.h: Contains the declarations of the filter cascade structures and functions.
• CascadeFilters.c: Contains the implementation of the filter cascade functions.

Simply include the CascadeFilters.h and CascadeFilters.c files in your project and ensure they are part of your build system.

To initialize a filter cascade, use filterCascadeInitialise:

FilterCascade cascade;
filterCascadeInitialise(
    &cascade,
    FILTER_TYPE_BANDPASS,  // Filter type
    3,                    // Number of filters
    1000.0,               // Center frequency (Hz)
    200.0,                // Bandwidth (Hz)
    44100.0               // Sampling frequency (Hz)
);

To process an input signal through the filter cascade:

double output = filterCascadeUpdate(&cascade, input);

To reset the filter's internal states:

filterCascadeReset(&cascade);

Initializes a filter cascade.

• Parameters:
  • cascade: Pointer to a FilterCascade structure.
  • type: Type of the filter (e.g., FILTER_TYPE_HIGHPASS).
  • numberOfFilters: Number of cascaded filters.
  • centerFrequency: Center frequency in Hz.
  • bandwidth: Bandwidth in Hz.
  • sampleFrequency: Sampling frequency in Hz.

Processes an input signal through the filter cascade and returns the filtered output.

• Parameters:
  • cascade: Pointer to the initialized FilterCascade.
  • input: Input signal value.

Resets the filter's internal states.

• Parameters:
  • cascade: Pointer to the FilterCascade.

• FILTER_ORDER_MAX: Maximum supported filter order (6).