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Lessons 2: How to Use a Feedback Loop

In flowcharting, a feedback loop is a set of reoccurring instructions connected to a decision point. Loops save time and space when used properly in a flowchart. For instance, if a robot was twenty steps away from a cliff ledge, a flowcharter could write: step, step, step, step, step, step, step, step, step, step, step, step, step, step, step, step, step, step, step, step, stop. Reference Figure 1 to see how a loop could be used instead.

Doing the science

  1. Start the Bomb ProBot Simulation by clicking on the "Sim" tab.
  2. Drag the "kneel" icon to the center of the information processing unit (IPU).
  3. Drag the "probe" icon to the center of the IPU.
  4. Note whether a bomb is present or not.
  5. Drag the "stand" icon to the center of the IPU.
  6. Continue working the robot through the minefield to the "Programming" section by dragging various commands to the IPU. Make sure to avoid all bombs.
  7. Design a flowchart for your commands on your own piece of paper.

Figure 1.

Do You Understand?

  1. Are there any parts of your flowchart that could be simplified by using a feedback loop?


  2. If so, redesign your flowchart to include your feedback loop.