SerialWombatWatchdog Class Reference

A class to wrap around a Serial Wombat Watchdog Pin. More...

#include <SerialWombatWatchdog.h>

Inheritance diagram for SerialWombatWatchdog:

Collaboration diagram for SerialWombatWatchdog:

Public Member Functions
	SerialWombatWatchdog (SerialWombatChip &serialWombat)
	Constructor for SerialWombatWatchdog.
void	begin (uint8_t pin, SerialWombatPinState_t normalState, SerialWombatPinState_t resetState, uint16_t timeout_mS, bool resetWombatAfterTimeout)
	Initialize a SerialWombatWatchdog.
void	updateResetCountdown (uint16_t time_mS)
	Reset the countdown timer to a specified number of mS.
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.

Additional Inherited Members
Protected Attributes inherited from SerialWombatPin
uint8_t	_pin = 255
SerialWombatChip &	_sw
uint8_t	_pinMode = 0

Detailed Description

A class to wrap around a Serial Wombat Watchdog Pin.

The Serial Wombat Watchdog Pin Mode is designed to improve system reliability in case of communications loss with the host device. This may be because the communications lines are no longer functional (e.g. I2C bus locked up) or the host ceases to communicate (Such as when an Arduino malfunctions due to issues allocating string memory).

Once enabled, the Serial Wombat Watchdog will change its output and optionally other Serial Wombat outputs to predefined states and optionally reset the Serial Wombat itself if a new Watchdog feeding message isn't received within a period of time specified in the initialization.

The output can be used to reset the host, for instance when connected to an Arduino reset pin, or used to shut off an output. For instance, a motor controlled by a SerialWombatWatchdog pin could be configured to turn off if the host doesn't periodically feed the watchdog.

A video tutorial is available:

https://youtu.be/fIObjmHmprY

Definition at line 29 of file SerialWombatWatchdog.h.

Constructor & Destructor Documentation

SerialWombatWatchdog()

SerialWombatWatchdog::SerialWombatWatchdog

(

SerialWombatChip &

serialWombat

)

Constructor for SerialWombatWatchdog.

Parameters

serialWombat

SerialWombat chip on which the SerialWombatWatchdog will run

Definition at line 3 of file SerialWombatWatchdog.cpp.

Member Function Documentation

begin()

void SerialWombatWatchdog::begin	(	uint8_t	pin,
		SerialWombatPinState_t	normalState,
		SerialWombatPinState_t	resetState,
		uint16_t	timeout_mS,
		bool	resetWombatAfterTimeout )

Initialize a SerialWombatWatchdog.

Parameters

pin	Pin on which the SerialWombat Watchdog will run. Valid values for SW4A: 0-3 SW4B: 1-3.
normalState	The pin state while the countdown has not expired. Valid values are SW_LOW, SW_HIGH or SW_INPUT
resetState	The pin state after the countdown has expired. Valid values are SW_LOW, SW_HIGH or SW_INPUT
timeout_mS	The number of milliseconds before the countdown will expire if not reset. Maximum value of 65535.
resetWombatAfterTimeout	TRUE: The Serial Wombat will set outputs to resetState, wait 10mS, then reset the Serial Wombat itself. FALSE: Pins stay in resetState, Wombat continues operating

Definition at line 7 of file SerialWombatWatchdog.cpp.

updateResetCountdown()

void SerialWombatWatchdog::updateResetCountdown

(

uint16_t

time_mS

)

Reset the countdown timer to a specified number of mS.

Parameters

time_mS

number of mS until countdown timer expires.

Definition at line 24 of file SerialWombatWatchdog.cpp.