[Greg McKaskle]

Just to review:
F1 enables, enter/return disables, and spacebar estops the robot. When on the field, F1 checks for new joystick insertions and that is it -- no other special keys.

Some History:
In an ideal world, operation in the pits/shop would be identical to the field. An attempt was made to use a dedicated estop button more like the field, but it is difficult to get a reliable button for the kit. When the dedicated and required USB button was dropped, the estop moved to the keyboard where it displaced the disable and took over the spacebar.

Outcome:
Maybe we can all agree that the big button should stop the bot, and it does. This seems good from a safety standpoint when driven by a tired team member or by a newbie or visitor.

That leaves us with the comparison of estop and disable. What is the difference and why.

One goal was for teams to become familiar with estop before they show up to a field -- to know it exists, perhaps use it a few times and understand that it doesn't just disable the bot. If you use it on the field, you are done.

Another goal was to encourage an inspection. You didn't just disable the robot, something caused you ESTOP the robot. Perhaps you should do an inspection for cause or for damage before compounding the issue. If you meant to disable but estopped instead, it is a small pain. If something about the robot's behavior truly deserved an estop reaction, you don't want to repeat that, right? Something probably needs to change. Similarly, an estop in an industrial setting would typically have a reset procedure different from an operator disable.

I've observed that many will power cycle the entire robot, and that is fine, but it does take longer. The minimum needed to clear an estop is to hit the physical reset button on the cRIO -- a toothpick works nicely. This leaves the radio powered and your road to learning the difference between estop and disable is a bit shorter.

Greg McKaskle