Datasheet

Page 140· Applied Robotics with the SumoBot

SUMMARY

This chapter reviewed how the SumoBot's IR detectors work, then introduced basic IR

detector testing along with IR interference, electrical continuity, and IR receiver

frequency response tests. Using these tests will help ensure that the SumoBot's IR

detectors are reliable, and more likely to detect an opponent than lead the SumoBot on a

snipe hunt. Side-mounted IR object detectors were added to the breadboard to give the

SumoBot peripheral vision.

This chapter also reviewed how QTI line sensors work, and then introduced a technique

you can use in your programs to read multiple QTI sensors, all in less than the time it

takes to read a single QTI sensor on a black surface. Self calibration techniques for QTI

line sensors were reviewed and refined so that your SumoBot can automatically adjust to

different sumo ring surfaces and ambient lighting conditions.

Programs were developed to read and track the values of each of the seven sensors (4 IR

detectors, 2 QTI sensors, and 1 pushbutton). A flags variable was introduced as a way of

storing the state of each of the individual sensor bits for pattern analysis. Temporary

variables for storage and counting were then incorporated into the program so that each

subroutine doesn't require its own special set of variables, which is an unnecessary use of

variable space.

Questions

1. What label designates the header with the front-left IR detector?

2. What connections does the SumoBot board make to the header with the front-left

IR detector that you don't have to build on a breadboard?

3. What does

FREQOUT 4, 1, 38500 do?

4. What does

FREQOUT 14, 1, 38500 do?

5. Are the SumoBot's IR receivers active-low or active-high output devices?

6. What is a ballast?

7. What's the main coding difference between "sniffing" for IR interference and IR

object detection?

8. What is an interruption in electrical continuity?

9. What problems can occur if your SumoBot's IR object detectors are set for

maximum sensitivity?

10. What does "frequency response" refer to?