Hysteresis< BITS, T_in, T_out > Class Template Reference

#include <AH/Filters/Hysteresis.hpp>

Detailed Description

template<uint8_t BITS, class T_in = uint16_t, class T_out = uint8_t>
class Hysteresis< BITS, T_in, T_out >

A class for applying hysteresis to a given input.

This reduces the noise by decreasing the resolution, and it prevents flipping back and forth between two values.

An example for BITS = 7 and an input from 0 to 1023

   7                                                     ┌───◄───┬───
o  6                                             ┌───◄───┼───►───┘
u  5                                     ┌───◄───┼───►───┘
t  4                             ┌───◄───┼───►───┘
p  3                     ┌───◄───┼───►───┘
u  2             ┌───◄───┼───►───┘
t  1     ┌───◄───┼───►───┘
   0 ────┴───►───┘
     0      128     256     384     512     640     768     896    1023
                                 i n p u t

Template Parameters

BITS	The number of bits to decrease in resolution. Increasing this number will result in a decrease in fluctuations.

Definition at line 36 of file Hysteresis.hpp.

Collaboration diagram for Hysteresis< BITS, T_in, T_out >:

Public Member Functions
bool	update (T_in inputLevel)
	Update the hysteresis output with a new input value. More...
T_out	getValue () const
	Get the current output level. More...
void	setValue (T_in inputLevel)
	Forcefully update the internal state to the given level. More...

Private Attributes
T_out	prevLevel = 0

Static Private Attributes
static constexpr T_in	margin = (1UL << BITS) - 1
static constexpr T_in	offset = 1UL << (BITS - 1)
static constexpr T_in	max_in = -1
static constexpr T_out	max_out = static_cast<T_out>(max_in >> BITS)

Member Function Documentation

update()

bool update ( T_in  inputLevel )

inline

Update the hysteresis output with a new input value.

Parameters

inputLevel

The input to calculate the output level from.

Return values

true	The output level has changed.
false	The output level is still the same.

Definition at line 48 of file Hysteresis.hpp.

getValue()

T_out getValue ( ) const

inline

Get the current output level.

Returns

The output level.

Definition at line 64 of file Hysteresis.hpp.

setValue()

void setValue ( T_in  inputLevel )

inline

Forcefully update the internal state to the given level.

Definition at line 69 of file Hysteresis.hpp.

Member Data Documentation

prevLevel

T_out prevLevel = 0

private

Definition at line 72 of file Hysteresis.hpp.

margin

constexpr T_in margin = (1UL << BITS) - 1

staticconstexprprivate

Definition at line 73 of file Hysteresis.hpp.

offset

constexpr T_in offset = 1UL << (BITS - 1)

staticconstexprprivate

Definition at line 74 of file Hysteresis.hpp.

max_in

constexpr T_in max_in = -1

staticconstexprprivate

Definition at line 75 of file Hysteresis.hpp.

max_out

constexpr T_out max_out = static_cast<T_out>(max_in >> BITS)

staticconstexprprivate

Definition at line 76 of file Hysteresis.hpp.

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The documentation for this class was generated from the following file:

• Hysteresis.hpp