Serial Wombat Arduino Library
Public Member Functions | List of all members
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
serialWombatSerialWombat 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
pinPin on which the SerialWombat Watchdog will run. Valid values for SW4A: 0-3 SW4B: 1-3.
normalStateThe pin state while the countdown has not expired. Valid values are SW_LOW, SW_HIGH or SW_INPUT
resetStateThe pin state after the countdown has expired. Valid values are SW_LOW, SW_HIGH or SW_INPUT
timeout_mSThe number of milliseconds before the countdown will expire if not reset. Maximum value of 65535.
resetWombatAfterTimeoutTRUE: 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_mSnumber of mS until countdown timer expires.