NXT Robot Tutorial (event 1 and 6)

  

          Event one and six are composed of an NXT robot, which begins and completes the Rube Goldberg machine.  To start, the robot’s touch sensor is push by the previous groups ball.  A touch sensor (Figure 1) is used because it is the easiest way for the robot to read that a moving object has hit it.  The code can be seen in Figure 2 and is also discussed below.

Figure 1 - NXT Robot and Sensors

Figure 2 - Block code of NXT-G software

Code:

      The first block in the code represents a conditional statement.  The code runs continuously while other group's Rube Goldberg's are running.  When the previous group's ball hits the robot's first touch sensor, it advances forward (block 2 in Figure 2).  Next, when an obstacle gets in the robots way, both motors stop (block 3 and 4 in Figure 2).  Another conditional statement waits until the obstacle is removed from the path by the other events in the Rube Goldberg machine.  At this point, the robot travels forward unlimitedly until the second touch sensor is pushed.  This is why there is a loop--to enable the robot to travel unlimitedly until a certain condition is met.  Finally, after the loop is broken, the robot stops moving.  

Construction:

    The NXT robot was build fairly simply.  Two motors were attached to the bottom, with compliment wheels.  The NXT computer was mounted above these motors.  Finally, supporting pieces were used to create an extension above the robot to help trigger the next event.