C

Our goal of this week was to do the "line follower" activity. First, we recapped the "remote control car" that they had created the previous week. We then explained the activity: Trevor was sick and needed to get to the hospital. However, the hospital was on the other side of a raging river, and their car had to follow along a narrow, curving bridge (a piece of tape on the floor) in order to get Trevor to the hospital safely. They had already attached the light sensor the previous week, so they were able to begin programming right away. We explained to the class the idea of tolerances - they would have to test the light value on the tape and on the floor. In their program, they would "wait for" a light value in between these two readings. This was a difficult concept for them to grasp, and we ended up explaining it to each group individually as they tested the two light values. They then needed to create a program that would allow their car to follow the line of tape by turning right until the car reached light (the floor), then turning left until it reached dark (the tape). We explained how this was very similar to the last program they made - the remote control car - except the light sensor is being used instead of the touch sensor. This was definitely one of the more difficult projects the students have seen so far. Some groups got frustrated, but by the end of the class, a majority of the cars could successfully "follow the line". This is a great activity, and the groups who succeed are very excited and proud of their accomplishment.