Datasheet

Chapter 4 • BOE Shield-Bot Navigation
140 • Robotics with the BOE Shield-Bot
• Controlling robot maneuver run-time to make the BOE Shield-Bot travel a pre-
determined distance or to rotate to a particular angle
• Compensating for hardware variance by adjusting servo speeds for straight travel
Engineering Skills
• Making observations and measurements to derive constants for a simple formula
that characterizes the cause-and-effect relationship between system input and
system output. (Yes it sounds fancy, but that’s what you did with that ruler.)
• The difference between a hardware adjustment and a software adjustment
• What an iterative process is, and using it for testing software adjustments
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.