* *radio-rx* is a non-blocking XBus input connected to a radio receiver.
* *motor-x* and *motor-y* are simple outputs connected to an omnidirectional motor.
* *harvest* is a simple output connected to a kelp harvesting apparatus.
* The harvester begins at grid location (0, 0).
* Locations to harvest are received over the *radio* as (X, Y) coordinates.
* If at least one unharvested location remains, move toward the *oldest* location, activating the *harvest* signal when the harvester is over *any* location.

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* Setting *motor-x* or *motor-y* to 100 for 1 time unit will move the harvester in the +X or +Y direction, respectively. Setting a *motor* to 50 will cause it to not move in that direction. Setting a *motor* to 0 will move it in the opposite direction.
* Since the harvester can move in both the X and Y axes simultaneously, diagonal moves should be made whenever possible to take the shortest path.
* The harvester will never receive a command to harvest its starting location.
* There will never be more than 6 pending harvest locations.