CAPT_Slider

High level slider and wheel processing module. More...

Functions
uint16_t	CAPT_computeArcTanApprox (int32_t i32XComp, int32_t i32YComp)
uint16_t	CAPT_computeSliderVectors (tSensor *pSlider)
uint16_t	CAPT_computeWheelWrap (int16_t i16Position, uint16_t ui16MaxPosition)
void	CAPT_processSlider (tSensor *pSlider)
uint16_t	CAPT_getSensorPosition (tSensor *pSensor)
	Get the position value for a slider or wheel sensor. More...

Detailed Description

High level slider and wheel processing module.

Slider processing APIs apply to sliders and wheels. Sliders and wheels share sensor structures (tSlider). A wheel is identical to a slider, except its filtering algorithm allows wrap-around on the endpoints.

Version

VERSION Released on RELEASE_DATE

Function Documentation

CAPT_computeArcTanApprox()

uint16_t CAPT_computeArcTanApprox	(	int32_t	i32XComp,
		int32_t	i32YComp
	)

Trigonometric Arctan approximation

Perform an arctan(YComp/XComp) approximation using a linear approximation with basic error correction, to give max error of +- 1 degree. A full 0 to 360 degree output range is achieved.

Parameters

i32XComp,i32YComp

are the X and Y vectors

Returns

approximated arctan(Y/X) value (0 to 360 degrees mapped from 0 to 65535)

CAPT_computeSliderVectors()

uint16_t CAPT_computeSliderVectors

(

tSensor *

pSlider

)

Calculate Slider Position

Slider position is calculated using a vector sum method.

Parameters

pSlider

is a pointer to the Slider Sensor to process

Returns

Slider position

CAPT_computeWheelWrap()

uint16_t CAPT_computeWheelWrap	(	int16_t	i16Position,
		uint16_t	ui16MaxPosition
	)

Test for a wrap on slider / wheel

With the slider/wheel functionality working in a 0-360 degree vector plane, a value must always be checked if it has not wrapped, and thus must be kept between 0 and 360.

Parameters

i16Position	is the slider/wheel position to check for wrapping
ui16MaxPosition	is the wrapping value (relating to 360degrees)

Returns

the adjusted position to fit in 0 to slider/wheel resolution

CAPT_processSlider()

void CAPT_processSlider

(

tSensor *

pSlider

)

Perform processing for a Slider

Here processing is performed on a slider sensor implementation. This includes calculating the slider output position and filtering of this position.

Parameters

pSlider

is a pointer to the Slider Sensor to process

Returns

none

CAPT_getSensorPosition()

uint16_t CAPT_getSensorPosition

(

tSensor *

pSensor

)

Get the position value for a slider or wheel sensor.

This function provides easy access to the slider or wheel position value.

Parameters

pSensor

is a pointer to the sensor to query

Returns

The current slider position if touched, else 0xFFFF.