50 SERVO 04.2013
on the IR sensor that is pointed across the open fingers
— just like last month), the hand is closed and the arm is
raised to prevent it from interfering with other sensors.
The Move ToBeacon subroutine from last month moves
the arm toward the beacon.
The only change we made to this routine was to
force the robot to stop when something was detected by
the front perimeter sensor instead of the finger sensors
used previously. This was necessary because the gripper
is raised to prevent interference with the beacon
When the beacon is reached, the arm is lowered and
the object released. The arm is then raised back to its
There are several routines that initialize the arm and
perform basic arm movements. Let’s look first at the
ArmInit routine. It begins by telling the main RROS chip
that an external processor has been added, and that it is
a second RROS chip used as an arm controller.
The next line tells the RROS to invert all four signals
from the gripper sensors to indicate true when objects
are detected. Next, the command rSenseType
establishes that there are additional rSense() sensors