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The Learning Brick Sorter • Masterpiece 2 67

The Switchbox

The Switchbox sub-assembly is the means through which the user will train the Learning
Brick Sorter by providing the necessary feedback.The Switchbox sub-assembly is a small
self-contained unit that has no mechanical linkage to any other part of the robot, except
the two electrical connections to the RCX. For this reason, the position of this unit is
not overly critical. Provided that it doesn’t interfere with the movement of the Arm sub-
assembly, and provided that you keep it attached to the RCX, you can place it wherever
you prefer.
All in all, this Switchbox is nothing more than a pair of touch sensors assigned to
define actions as either right or wrong.After having placed a brick in one of the bins, the
robot will stop and wait for the user to press one of these sensors, according to whether
the bin was the right one or a wrong one.The program will then use this information to
“learn” from this feedback.
Instead of presenting the user two bare touch sensors to use as push buttons, I chose
to encapsulate the sensors into small structures, so they can be activated by using two dif-
ferent colored levers.

Switchbox Step 0 Switchbox Step 1