Grabbing Output from Robot Sensors

[1951-44U]

We're trying to connect the Classmate, Dev Laptop, and Robot so we can get feedback from our sensors in WindRiver C++.

We've connected it with a setup like this: dev laptop and classmate to router, which wirelessly connects to the robot. We've also tried hooking everything up directly to an ethernet switch. Still don't work.

When we try to connect with the console, the Classmate intermittently displays "Watchdog Not Fed". The robot reaction works, but is delayed when we try the drives. The output on the console has all 0 values. Without the Dev Laptop in this network, the robot works fine.

We fed, disabled, and even tried to kill Watchdog. We've tried different laptops. It still does not work.

-1951-44U

[BradAMiller]

The Watchdog not fed message means that the running program enabled the watchdog timer and is not calling the Feed() method before the expiration time runs out. If you have autonomous code that does a long Wait() you are probably running out the watchdog timer. If you have a program loop in your teleop code then you might be missing a call to Feed().

The configuration of the programming laptop and driver station shouldn't matter if they are all successfully talking to the robot.

Are you running some sample code or your own program?

[1951-44U]

We are using our own code. There are no loops in our teleop, and we haven't used the autonomous yet. We had GetWatchdog().Feed() 's all over the teleop when we were trying to feed the watchdog.

[ranc]

Wait you have no while(true) or while(IsOperatorControl()) loops?
I remember leaving out said while loop and getting the same issue.

[1951-44U]

Well, we have those loops, but we have no others. We have Feed()'s within those loops, too.

Does the line "GetWatchdog().SetExpiration(0.1);" in the initializers do anything? Can I delete this?

[BradAMiller]

Originally Posted by 1951-44U

Well, we have those loops, but we have no others. We have Feed()'s within those loops, too.

Does the line "GetWatchdog().SetExpiration(0.1);" in the initializers do anything? Can I delete this?

That sets the expiration time of the watchdog timer. That means that it must be fed within 0.1 second (100 milliseconds) before it times out and the motors stop with the "Watchdog not fed" error message.

If there are any Wait() calls in your loop that are greater than 100ms, the the watchtog will also time out.

[1951-44U]

Can I SetExpiration at some ridiculously high number to get rid of the watchdog error?

[ranc]

You could use GetWatchdog().SetEnabled(0) for turning it off right before your long wait and then use GetWatchdog().SetEnabled(1) for turning it back on again when you're not initializing whatever you're initializing (i'm assuming your long wait is due to setup of some component)

[1951-44U]

I'll try that tomorrow. But I haven't a single Wait() in the program. ._.

Can I completely delete the GetWatchdog().SetExpiration() or completely replace it with the .SetEnabled()?

[ranc]

Yes I think you could just use set enabled to turn it off

[1951-44U]

We tried setting the Watchdog at SetEnabled(0), but still get the same problem. We set it at 0 in the initializers, in autonomous, in the operator function, and in the operator loop. Setting SetExpiration() at an impossibly high number had no success, either.