Watchdog Class Reference

#include <Watchdog.h>

Inheritance diagram for Watchdog:

Inheritance graph
Collaboration diagram for Watchdog:

Collaboration graph

List of all members.

Public Member Functions

 Watchdog (void)
 ~Watchdog (void)
bool Feed (void)
void Kill (void)
unsigned int GetTimer (void)
unsigned int GetExpiration (void)
void SetExpiration (unsigned int expiration_ms)
bool GetEnabled (void)
void SetEnabled (bool enabled)
bool IsAlive (void)
bool IsSystemActive (void)

Detailed Description

Watchdog timer class. The watchdog timer is designed to keep the robots safe. The idea is that the robot program must constantly "feed" the watchdog otherwise it will shut down all the motor outputs. That way if a program breaks, rather than having the robot continue to operate at the last known speed, the motors will be shut down.

This is serious business. Don't just disable the watchdog. You can't afford it!

Constructor & Destructor Documentation

Watchdog::Watchdog ( void   ) 

The Watchdog is born.

Watchdog::~Watchdog ( void   ) 

Time to bury him in the back yard.

Member Function Documentation

bool Watchdog::Feed ( void   ) 

Throw the dog a bone.

When everything is going well, you feed your dog when you get home. Let's hope you don't drive your car off a bridge on the way home... Your dog won't get fed and he will starve to death.

By the way, it's not cool to ask the neighbor (some random task) to feed your dog for you. He's your responsibility!

Returns the previous state of the watchdog before feeding it.

void Watchdog::Kill ( void   ) 

Put the watchdog out of its misery.

Don't wait for your dying robot to starve when there is a problem. Kill it quickly, cleanly, and humanely.

unsigned int Watchdog::GetTimer ( void   ) 

Read how long it has been since the watchdog was last fed.

The number of milliseconds since last meal.

unsigned int Watchdog::GetExpiration ( void   ) 

Read what the current expiration is.

The number of milliseconds before starvation.

void Watchdog::SetExpiration ( unsigned int  expiration_ms  ) 

Configure how many milliseconds your watchdog can be neglected before he starves to death.

expiration_ms The number of milliseconds before starvation.

bool Watchdog::GetEnabled ( void   ) 

Find out if the watchdog is currently enabled or disabled (mortal or immortal).

Enabled or disabled.

void Watchdog::SetEnabled ( bool  enabled  ) 

Enable or disable the watchdog timer.

When enabled, you must keep feeding the watchdog timer to keep the watchdog active, and hence the dangerous parts (motor outputs, etc.) can keep functioning. When disabled, the watchdog is immortal and will remain active even without being fed. It will also ignore any kill commands while disabled.

enabled Enable or disable the watchdog.

bool Watchdog::IsAlive ( void   ) 

Check in on the watchdog and make sure he's still kicking.

This indicates that your watchdog is allowing the system to operate. It is still possible that the network communications is not allowing the system to run, but you can check this to make sure it's not your fault. Check IsSystemActive() for overall system status.

If the watchdog is disabled, then your watchdog is immortal.

Is the watchdog still alive?

bool Watchdog::IsSystemActive ( void   ) 

Check on the overall status of the system.

Is the system active (i.e. PWM motor outputs, etc. enabled)?

The documentation for this class was generated from the following files:

Generated on Thu Oct 2 14:01:34 2008 for WPI Robotics Library by  doxygen 1.5.5