A class to make resistance measurements with the Serial Wombat 18AB chip. More...

#include <SerialWombatResistanceInput.h>

Inheritance diagram for SerialWombatResistanceInput:

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Collaboration diagram for SerialWombatResistanceInput:

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Public Member Functions
	SerialWombatResistanceInput (SerialWombatChip &serialWombatChip)
	Constructor for the SerialWombatResistanceInput class.

int16_t	begin (uint8_t pin)
	Initialize a resistance input on a given pin.

int16_t	begin (uint8_t pin, uint16_t averageSamples, uint16_t filterConstant)
	Initialize a resistance input on a given pin.

int16_t	begin (uint8_t pin, uint16_t averageSamples, uint16_t filterConstant, ResistanceInputPublicDataOutput output)
	Initialize a resistance input on a given pin.

uint16_t	readFilteredOhms ()
	Retreive a filtered Resistance measurement.

uint16_t	readAveragedOhms ()
	Retreive an averaged Resistance measurement.

uint16_t	readMaximumOhms (bool resetAfterRead)
	Retreive the maximum single sample Resistance value in Ohms.

uint16_t	readMinimumOhms (bool resetAfterRead)
	Retreive the maximum single sample Resistance value in Ohms.

uint8_t	pin ()
	Used for inheritance.

uint8_t	swPinModeNumber ()
	Used for ineheritance.

Public Member Functions inherited from SerialWombatPin
	SerialWombatPin (SerialWombatChip &serialWombatChip)
	Instantiates a Serial Wombat Pin.

	SerialWombatPin (SerialWombatChip &serialWombatChip, uint8_t pin)
	Instantiates a Serial Wombat Pin.

uint16_t	readPublicData ()
	Read the 16 Bit public data associated with this pin.

void	pinMode (uint8_t mode, bool pullDown=false, bool openDrain=false)
	Set pin to INPUT or OUTPUT, with options for pull Ups and open Drain settings.

void	digitalWrite (uint8_t val)
	Set output pin High or Low.

int	digitalRead ()
	Reads the state of the Pin.

uint16_t	writePublicData (uint16_t value)
	Write a 16 bit value to this pin.

uint8_t	pin ()
	Returns the current SW pin number. Used primarily for virtual calls by derived classes.

uint8_t	swPinModeNumber ()
	Returns the Mode number. Used primarily by derived classes to populate packet data.

int16_t	initPacketNoResponse (uint8_t packetNumber, uint8_t param0=0x55, uint8_t param1=0x55, uint8_t param2=0x55, uint8_t param3=0x55, uint8_t param4=0x55)

int16_t	initPacketNoResponse (uint8_t packetNumber, uint16_t param0=0x55, uint8_t param1=0x55, uint8_t param2=0x55, uint8_t param3=0x55)

int16_t	initPacketNoResponse (uint8_t packetNumber, uint16_t param0, uint16_t param1, uint8_t param2=0x55)

int16_t	disable ()
	Disables the pin mode (if applicable)

int16_t	enablePullup (bool enabled)
	Enables the weak pull up on a pin. Implemented on SW18AB only.

int16_t	enablePullDown (bool enabled)
	Enables the weak pull down on a pin. Implemented on SW18AB only.

int16_t	enableOpenDrain (bool enabled)
	Enables open drain mode on a pin. Implemented on SW18AB only.

Public Member Functions inherited from SerialWombatAbstractProcessedInput
	SerialWombatAbstractProcessedInput (SerialWombatChip &sw)
	Constructor for the SerialWombatAbstractScaledOutput Class.

int16_t	writeInverted (bool inverted)
	if enabled subtract the input value from 65535 before doing any other processing.

int16_t	writeFirstOrderFilteringConstant (uint16_t constant)
	Set a first order filtering constant to be applied to the signal Higher is heavier filtering.

int16_t	writeAveragingNumberOfSamples (uint16_t numberOfSamples)
	Set a number of samples to average for each update of the downstream signal.

int16_t	writeExcludeBelowAbove (uint16_t low, uint16_t high)
	Sets input value ranges which are discarded rather than processed.

int16_t	configureQueue (SerialWombatQueue *queue, Period period, bool queueHighByte=true, bool queueLowByte=true)
	Sets up the queueing feature for this pin mode. Queue must have been initialized prior to this queue.

int16_t	configureOutputValue (OutputValue outputValue)
	Configures whether the pin's public data value is averaged, filtered, or neither.

int16_t	writeTransformScaleRange (uint16_t min, uint16_t max)
	Scale incoming values to a range of 0 to 65535.

int16_t	writeTransformLinearMXB (int32_t m, int32_t b)
	Scale incoming values based on an mx+b linear equation.

int16_t	configureIntegrator (uint16_t negativeMaxIndex, uint16_t negativeMidIndex, uint16_t negativeDeadZone, uint16_t positiveDeadZone, uint16_t positiveMidIndex, uint16_t positiveMaxIndex, uint16_t midIncrement, uint16_t maxIncrement, uint16_t initialValue, uint8_t updateFrequencyMask=0)
	Sort incoming data into one of 5 ranges, and integrate based on linear interpolation in those ranges.

int16_t	writeProcessedInputEnable (bool enabled)
	Enables or disables all input processing functions If disabled, the raw input value is placed directly in the pin's 16 bit public data buffer.

uint16_t	readMinimum (bool resetAfterRead=false)
	Retreive the maximum public data output value since the last call with reset= true.

uint16_t	readMaximum (bool resetAfterRead=false)
	Retreive the minimum public data output value since the last call with reset= true.

uint16_t	readAverage ()
	Retreive the last completed averaged value.

uint16_t	readFiltered ()
	Retreive the filtered value.

Additional Inherited Members
Public Types inherited from SerialWombatAbstractProcessedInput
enum	Period { PERIOD_1mS = 0 , PERIOD_2mS = 1 , PERIOD_4mS = 2 , PERIOD_8mS = 3 , PERIOD_16mS = 4 , PERIOD_32mS = 5 , PERIOD_64mS = 6 , PERIOD_128mS = 7 , PERIOD_256mS = 8 , PERIOD_512mS = 9 , PERIOD_1024mS = 10 }

enum	OutputValue { RAW = 0 , FIRST_ORDER_FILTERED = 1 , AVERAGE = 2 }

enum	Transform { NONE = 0 , SCALE_RANGE = 1 , LINEAR_MXB = 2 }

Protected Attributes inherited from SerialWombatPin
uint8_t	_pin = 255

SerialWombatChip &	_sw

uint8_t	_pinMode = 0

Detailed Description

A class to make resistance measurements with the Serial Wombat 18AB chip.

The SerialWombatResistanceInput class is used to make resistance measurements on a given pin up to about 60 kOhm.

This pin mode is only available on the SerialWombat 18AB chip

Any analog-capable pin may be used to make a measurement (0-4, 16-19).

Averaging of samples and first order IIR filtering (20 Hz sampling) of input are available

For a good explanation of 1st order FIR filter calculations, see: https://www.monocilindro.com/2017/04/08/how-to-implement-a-1st-order-iir-filter-in-5-minutes/

Filtering adds lag. The higher the filter constant value, the longer it takes for the filter to settle when given a steady input.

Declare and initialize a SerialWombatResistanceInput instance for each pin being used as a resistance input.

A tutorial is available here:

https://youtu.be/8ynBmxZSE_M

Definition at line 74 of file SerialWombatResistanceInput.h.

Constructor & Destructor Documentation

◆ SerialWombatResistanceInput()

SerialWombatResistanceInput::SerialWombatResistanceInput ( SerialWombatChip & serialWombatChip )

inline

Constructor for the SerialWombatResistanceInput class.

Parameters

SerialWombat a reference to the Serial Wombat chip on which the Resistance Input will be measured

Definition at line 82 of file SerialWombatResistanceInput.h.

Member Function Documentation

◆ begin() [1/3]

int16_t SerialWombatResistanceInput::begin ( uint8_t pin )

inline

Initialize a resistance input on a given pin.

This intialization turns on sample averaging to 64 samples

Parameters

pin	The Serial Wombat pin to set. Must be an analog pin (0-4, 16-19)

Returns: Returns a negative error code if initialization failed.

Definition at line 93 of file SerialWombatResistanceInput.h.

◆ begin() [2/3]

int16_t SerialWombatResistanceInput::begin	(	uint8_t	pin,
		uint16_t	averageSamples,
		uint16_t	filterConstant )

inline

Initialize a resistance input on a given pin.

Parameters

pin	The Serial Wombat pin to set. Must be an analog pin (0-4, 16-19)
averageSamples	Number of samples to average.
filterConstant	First Order IIR filter constant, expressed as 1/65536ths . Values closer to 65536 give heavier filtering. Sample frequency is 20Hz.

Returns: Returns a negative error code if initialization failed.

Definition at line 112 of file SerialWombatResistanceInput.h.

◆ begin() [3/3]

int16_t SerialWombatResistanceInput::begin	(	uint8_t	pin,
		uint16_t	averageSamples,
		uint16_t	filterConstant,
		ResistanceInputPublicDataOutput	output )

inline

Initialize a resistance input on a given pin.

Parameters

pin	The Serial Wombat pin to set. Must be an analog pin (0-4, 16-19)
averageSamples	Number of samples to average.
filterConstant	First Order IIR filter constant, expressed as 1/65536ths . Values closer to 65536 give heavier filtering. Sample frequency is 20 Hz.
publicDataOutput	What to output as pin public data

Returns: Returns a negative error code if initialization failed.

Definition at line 129 of file SerialWombatResistanceInput.h.

◆ pin()

uint8_t SerialWombatResistanceInput::pin ( )

inlinevirtual

Used for inheritance.

Implements SerialWombatAbstractProcessedInput.

Definition at line 221 of file SerialWombatResistanceInput.h.

◆ readAveragedOhms()

uint16_t SerialWombatResistanceInput::readAveragedOhms ( )

inline

Retreive an averaged Resistance measurement.

Conversion is based on the most recent averaged Resistance value taken by the Serial Wombat at the command time.

Returns: A 16 bit unsigned value indicating the ohms of the Resistance conversion

Definition at line 164 of file SerialWombatResistanceInput.h.

◆ readFilteredOhms()

uint16_t SerialWombatResistanceInput::readFilteredOhms ( )

inline

Retreive a filtered Resistance measurement.

Conversion is based on the most recent filtered Resistance value taken by the Serial Wombat at the command time.

Returns: A 16 bit unsigned value indicating the filtered Resistance result

Definition at line 145 of file SerialWombatResistanceInput.h.

◆ readMaximumOhms()

uint16_t SerialWombatResistanceInput::readMaximumOhms ( bool resetAfterRead )

inline

Retreive the maximum single sample Resistance value in Ohms.

The maximum value the Serial Wombat chip has seen on that pin since last reset of Min/Max

Parameters

resetAfterRead If True, maximum value is set to 0 after read so that subsequent values become maximum. Also resets minimum to next sample.

Returns: A 16 bit unsigned value indicating maximum Resistance Ohms

Definition at line 184 of file SerialWombatResistanceInput.h.

◆ readMinimumOhms()

uint16_t SerialWombatResistanceInput::readMinimumOhms ( bool resetAfterRead )

inline

Retreive the maximum single sample Resistance value in Ohms.

The maximum value the Serial Wombat chip has seen on that pin since last reset of Min/Max

Parameters

resetAfterRead If True, maximum value is set to 0 after read so that subsequent values become maximum. Also resets minimum to next sample.

Returns: A 16 bit unsigned value indicating maximum Resistance Ohms

Definition at line 207 of file SerialWombatResistanceInput.h.

◆ swPinModeNumber()

uint8_t SerialWombatResistanceInput::swPinModeNumber ( )

inlinevirtual

Used for ineheritance.

Implements SerialWombatAbstractProcessedInput.

Definition at line 222 of file SerialWombatResistanceInput.h.

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SerialWombatResistanceInput()

Member Function Documentation

◆ begin() [1/3]

◆ begin() [2/3]

◆ begin() [3/3]

◆ pin()

◆ readAveragedOhms()

◆ readFilteredOhms()

◆ readMaximumOhms()

◆ readMinimumOhms()

◆ swPinModeNumber()