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>

Inheritance diagram for SerialWombatWatchdog:
SerialWombatPin

Public Member Functions

 SerialWombatWatchdog (SerialWombatChip &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...
 
- Public Member Functions inherited from SerialWombatPin
 SerialWombatPin (SerialWombatChip &serialWombatChip)
 Instantiates a Serial Wombat Pin. More...
 
 SerialWombatPin (SerialWombatChip &serialWombatChip, uint8_t pin)
 Instantiates a Serial Wombat Pin. More...
 
uint16_t readPublicData ()
 Read the 16 Bit public data associated with this pin. More...
 
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. More...
 
void digitalWrite (uint8_t val)
 Set output pin High or Low. More...
 
int digitalRead ()
 Reads the state of the Pin. More...
 
uint16_t writePublicData (uint16_t value)
 Write a 16 bit value to this pin. More...
 
uint8_t pin ()
 Returns the current SW pin number. Used primarily for virtual calls by derived classes. More...
 
uint8_t swPinModeNumber ()
 Returns the Mode number. Used primarily by derived classes to populate packet data. More...
 

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

Constructor & Destructor Documentation

◆ SerialWombatWatchdog()

SerialWombatWatchdog::SerialWombatWatchdog ( SerialWombatChip serialWombat)

Constructor for SerialWombatWatchdog.

Parameters
serialWombatSerialWombat chip 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.