Programming the last thing a robot does...

[Qbranch]

Originally Posted by Squirrel Lord

Speaking as someone almost entirely ignorant of programming, I can only really describe things I have seen done in the past. I do know, however, that last year, the programmers were able to make our gripper release the tube whenever the robot was shut off... I will ask them more about this and get back to you.

That's easy: wire your pneumatic solenoid for the gripper so that the when it's not energized the gripper is open. When the control is disabled, the user processor's RESET pin (not the reset button) is held to ground. This puts the processor into its initial state. For more info on the initial state of the processor, see the 18f8722 datasheet.

This is very similar to how 1501 (who we were very happy to play with this past two boilermaker regionals) designed their lift mechanesim last year on their elevator robot. In it's normal state, not energized, the solenoid gating air to their lift pistons held the robot in the 'up' position. As soon as the match began, they energized the solenoid to put the robot down. When the match ended, even if they forgot to hit the lift button the robot would used it's stored pneumatic energy to lift the robot when the solenoid became de-energized as the processor entered it's reset state.

You can get some pretty neat endgame stuff out of this. Also remember that airplane servos and motors relax when there is no pwm input (robot disabled), so if you used a spring or something you can get clever there too.

-q