filter.h File Reference

Core filter library. More...

#include <stdint.h>
#include <stdbool.h>

Go to the source code of this file.

Data Structures
struct	core_filter_s

Typedefs
typedef struct core_filter_s	core_filter_t

Functions
float	core_filter_update (float x, core_filter_t *filt)
	Get an output value from the filter. This is the primary function being called.
bool	core_filter_rolling_avg_init (uint8_t order, core_filter_t *filt)
	Initialize a rolling average. This will apply an even coefficient across the last (order) inputs to the filter.
bool	core_filter_exp_lowpass_init (float a, core_filter_t *filt)
	Initialize an exponential lowpass filter.

Detailed Description

Core filter library.

This core library components is used to handle general-purpose digital filters. The filters work via coefficient arrays, which determine the weighting that previous inputs and outputs have on the current output.

These arrays and the corresponding information for them will be set up within the specialized init functions for each filter type.

Function Documentation

core_filter_exp_lowpass_init()

bool core_filter_exp_lowpass_init	(	float	a,
		core_filter_t *	filt )

Initialize an exponential lowpass filter.

Parameters

a	Alpha value for the filter. This represents the weighting of the current input. The weighting of the previous output is indirectly propertional to (a)
filt	Filter object to apply input to

Returns

True if initialized, false if error occured

core_filter_rolling_avg_init()

bool core_filter_rolling_avg_init	(	uint8_t	order,
		core_filter_t *	filt )

Initialize a rolling average. This will apply an even coefficient across the last (order) inputs to the filter.

Parameters

order	Number of inputs to consider in the rolling average (an order of 1 is no filter, the output will be the input)
filt	Filter object to apply input to

Returns

True if initialized, false if error occured

core_filter_update()

float core_filter_update	(	float	x,
		core_filter_t *	filt )

Get an output value from the filter. This is the primary function being called.

Parameters

x	Input to filter
filt	Filter object to apply input to

Returns

The filter output