Chapter 4 Challenges

Questions

  1. What direction does the left wheel have to turn to make the BOE Shield-Bot go forward? What direction does the right wheel have to turn?
  2. When the BOE Shield-Bot pivots on one wheel to the left, what are the wheels doing?  What code do you need to make the BOE Shield-Bot pivot left?
  3. If your BOE Shield-Bot veers slightly to one side when you are running a sketch to make it go straight ahead, how do you correct this?  What command needs to be adjusted and what kind of adjustment should you make?
  4. If your BOE Shield-Bot travels 11 in/s, how many milliseconds will it take to make it travel 36 inches?
  5. Why does a for loop that ramps servo speed need delay(20) in it?
  6. What kind of variable is great for storing multiple values in lists?
  7. What kind of loops can you use for retrieving values from lists? 
  8. What statement can you use to select a particular variable and evaluate it on a case-by-case basis and execute a different code block for each case?
  9. What condition can you append to a do-loop?

Exercises

  1. Write a routine that makes the BOE Shield-Bot back up at full speed for 2.5 seconds.
  2. Let’s say that you tested your servos and discovered that it takes 1.2 seconds to make a 180° turn with right-rotate.  With this information, write routines to make the BOE Shield-Bot perform 30, 45, and 60 degree turns.
  3. Write a routine that makes the BOE Shield-Bot go straight forward, then ramp into and out of a pivoting turn, and then continue straight forward.

Projects

  1. It is time to fill in column 3 of Table 2‑2.  To do this, modify the us arguments in the writeMicroseconds calls in the ForwardThreeSeconds sketch using each pair of values from column 1.  Record your BOE Shield-Bot’s resultant behavior for each pair in column 3.  Once completed, this table will serve as a reference guide when you design your own custom BOE Shield-Bot maneuvers.
  2. The diagram shows two simple courses. Write a sketch that will make your BOE Shield-Bot navigate along each figure.  Assume straight-line distances (the triangle’s sides and the diameter of the circle) are either 1 yard or 1 meter.

Diagram of a circle and an equilateral triangle, as courses the BOE Shield-Bot must drive on.