SerialWombatWatchdog Class Reference

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

#include <SerialWombatWatchdog.h>

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

Detailed Description

A class to wrap around a Serial Wombat Watchdog Pin.

The Serial Wombat Watchdog 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

Constructor & Destructor Documentation

SerialWombatWatchdog()

SerialWombatWatchdog::SerialWombatWatchdog

(

SerialWombat &

serialWombat

)

Constructor for SerialWombatWatchdog.

Parameters

serialWombat

SerialWombat on which the SerialWombatWatchdog will run

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

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.