Re: Driver Station + Space Bar
 

See Mark's note below. That's a good question for the NI guys though: I'd like to know more about the differences too.

There is a fairly good argument why the mapping should not be changed. If everyone in FIRST knows the mapping, then anyone in FIRST can stop your robot by smacking the spacebar/enter key. Safety is one of those items where you have to take the attitude that, if it can happen, it will.

Re: Driver Station + Space Bar
 

I think a good solution to the problem may be a better way to un-e-stop the robot beside a reboot.

Would there be some way to hit a specific combination of keys (ctrl+shift+alt+U ?) that could then disengage the e-stop? I should note, I have very little knowledge of how the DS is built or what the e-stop is actually doing when it is engaged.

-Brando

Re: Driver Station + Space Bar
 

Neither one actually stops code execution on the cRIO.
The user code continues to hum along blissfully.
I just tested it to make sure.

Re: Driver Station + Space Bar
 

Estop is simply a latched disable. Neither of them bother to abort user code, but instead they will both set outputs to safe values, ignoring user code settings. Sensors and other features continue to operate as normal. Ideally, estop would kill power, but that isn't something the system can easily achieve.

When FIRST stopped using the estop USB button, which wasn't a very robust button anyway, the decision was made to remap the buttons. Previously space disabled the robot, and I believe enter did as well. The estop button emitted ctl-shift-enter, so that combo would estop the robot no matter what keyboard it came from.

The new mapping is that enter disables and space estops. F1 will actually enable the robot, and while running will enumerate the joysticks again in case something came unplugged, etc.

As for another way to un-estop the robot, it has been discussed many times, and the folks who own the decision feel that it is very important to enforce good safety processes. Part of that process is to walk to the robot and give it a visual inspection after an estop. It is also good to give it some thought before you repeat the steps that led to an estop you are currently recovering from. If you are in such a hurry that an estop was necessary, perhaps that is too much of a hurry.

As for the value of estop when not in a competition? The argument is that this allows teams to learn about estop before an event. If, in a practice setting, you estop your robot, it is rather permanent -- ditto for the competition field. If a team became used to the inconsistent practice setup, perhaps even using this as a driving technique, that would be unfortunate. So, the controls are as consistent to the field conditions as budget will allow. If it were feasible to ship large red mushroom buttons or panic triggers or other equipment, that would also likely be a part of the practice and development setup as well.

Greg McKaskle

Re: Driver Station + Space Bar
 

@Greg McKaskle

Interesting information on the F1 button and enumeration. Where did you find this info?

Also, I think the space bar estop is here to stay even if a budgeting allows for an external button like the ones on the field. From a safety perspective two buttons is better than one and the other this is the space bar can not easily be covered or accidentally be pressed by someone who is not at the controls. I know some teams in 2010 opted to cover their button so it would not be accidentally be pressed. This presents a huge safety hazard.

Re: Driver Station + Space Bar
 

Lore, word of mouth, oral tradition, and several years of intimate familiarity with the control system. :)

Oh, and it's described in both the "Getting Started with the 2012 FRC Control System" document and the FMS White Paper. I'm sure it was in one of the 2011 setup documents too. Someone on each team should have read those, right?

Re: Driver Station + Space Bar
 

"Where did you find this info?" From a reliable source of course.

If an external estop is detectable, it could be used as a key -- the robot wouldn't run without it. At that point I'm pretty sure you could have the space bar back.

Greg McKaskle

Re: Driver Station + Space Bar
 

While I would like 1+ external e-stops, I wouldn't want to remove the spacebar as one. There would be no guarantee that an external e-stop is anywhere near the person that is enabling the robot. (As even USB buttons could be on long extensions, or under the table, etc.) I think the current use of the spacebar is the most appropriate as an e-stop even with the reintroduction of external e-stops.

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