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Lesson 5.5: Challenge — Build Intake Logic for Multi-Stage Game Piece Sorting

Technical Context​

A "Logic Tree" is a complex arrangement of decisions that allows the robot to handle variable field conditions autonomously. This prevents failures in game element management by creating specific behaviors for different scenarios — such as varying motor power based on whether a Color Sensor detects a friendly or opposing alliance element.

How to Design a Multi-Stage Intake Decision Tree​

This challenge requires nesting if/else statements within each other, or using a complex else if chain, to manage a hardware subsystem. The goal is to implement a state-dependent controller. For example, the intake mechanism should run at 100% if empty, 50% if one item is detected, and 0% (Stop) if the distance sensor indicates the intake is full. By structuring this logic correctly, you minimize the driver's cognitive load and maximize the robot's cycle efficiency.

Annotated Code​

@Override
public void loop() {
    double dist     = board.getDistance(DistanceUnit.CM);
    int    redValue = board.getAmountRed();

    if (dist < 5.0) {
        // Logic Level 1: Intake is full — stop immediately
        intake.setPower(0.0);
        telemetry.addData("Intake", "FULL - STOPPED");
    } else if (redValue > 200) {
        // Logic Level 2: Wrong alliance element detected — eject
        intake.setPower(-1.0);
        telemetry.addData("Intake", "WRONG ELEMENT - EJECTING");
    } else {
        // Logic Level 3: Ready to intake — follow driver input
        intake.setPower(gamepad1.right_trigger);
        telemetry.addData("Intake", "READY");
    }
}

Fill-in-the-Blank Practice​

  1. When one if statement is placed inside another if statement's block, it is referred to as a/an __________ conditional.
  2. Building a multi-stage logic tree helps robots handle variable conditions in the __________ phase of a match.
  3. A well-designed logic tree ensures that the setPower() method always receives a/an __________ value between -1.0 and 1.0.
Show answers
  1. nested
  2. autonomous
  3. valid (unambiguous / single)

Template Challenge​

Robot Scenario: Create a sorting logic. If the Color Sensor sees Blue (blue() > 100), set Servo 1 to 0.0. If it sees Red (red() > 100), set Servo 1 to 1.0. If it sees neither, set Servo 1 to 0.5.

Unit 5 simulator
Supports gamepad-driven `if`, `else if`, and `else` logic with live branch visualization.
Includes truth-table and condition-inspector views, plus mock distance and color sensor inputs when needed.
Best for practicing decision logic, thresholds, and simple actuator commands.
Show answer
@Override
public void loop() {
    if (sensor.blue() > 100) {
        sorter.setPosition(0.0);
    } else if (sensor.red() > 100) {
        sorter.setPosition(1.0);
    } else {
        sorter.setPosition(0.5);
    }
}

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