Line Following Timing Guide (3 Hours)

Audience: Ages 9-14, no coding experience required.
Goal: Calibrate the color sensor, follow a line with proportional control, tune the gain, and showcase the week.

Note: today ends a little differently — the showcase runs 30 minutes (11:30-12:00) instead of 15, so Robotics Block 2 is shorter. Leave that hard stop; it’s the week’s payoff.

9:00-9:15 — Arrival Game: Debug the Dance

Students fix a deliberate bug in a written dance sequence to prime the read-the-code mindset.

  • Objective: pre-teach “the robot did exactly what the steps said” before touching code.
  • Flow:
    1. As students arrive, show a short written move/dance sequence with one deliberate bug.
    2. Students spot and fix the bug, then run the corrected sequence.
  • Watch for: students “fixing” it by intuition instead of reading the steps literally.
  • Tip: keep it light; this just primes the read-the-code mindset for the day.

9:15-9:25 — Mission Huddle + Catch-Up

Recap Day 4 sensor/if-else, frame today’s line-follow + showcase, and assign roles.

  • Objective: recap sensors/decisions and frame today’s mission.
  • Flow:
    1. Catch-up: quick recap of Day 4 — reading a sensor and reacting with if/else — so every team can read a value before we add steering.
    2. Today’s mission: follow a line with the color sensor, then showcase the week.
    3. Reinforce the mantra: “Bugs are sensor data.”
  • Tip: assign the first set of roles (Coder, Builder, Navigator, Tester) now.

9:25-10:25 — Robotics Block 1: Calibrate & First Follow

Measure BLACK/WHITE reflection, set the threshold midpoint, run the starter. Milestone: every team follows the line edge.

  • Objective: every team measures BLACK/WHITE, sets a threshold, and takes a first follow.
  • Flow:
    1. Add the color sensor to the setup (ColorSensor(Port.D)) and confirm the actual port.
    2. Print reflection() over the black tape, then over the white floor; record both.
    3. Set BLACK, WHITE, and the threshold (their midpoint) on the worksheet.
    4. Run the starter; watch the robot follow the edge of the line.
    5. Rotate roles ~halfway through the block.
  • Off-robot task: Navigator tapes/lays out the line course and predicts where it’ll wobble.
  • Watch for:
    • Low contrast surfaces — fix the tape/floor first or nothing works
    • Sensor mounted too high — it needs to face down, near the floor
    • Students treating 10/80 as “the answer” — those are guesses to measure
    • The robot following the other edge and running off — start it on the correct side
  • Tip: get one team reading clean BLACK/WHITE values fast, then have them help neighbors.

10:25-10:35 — Energizer

  • Quick Debug the Dance (full-group) or stretch-and-shake. Get everyone up and moving.

10:35-10:50 — Snack Break

  • Check allergies. Keep all food and drinks away from kits and laptops.

10:50-11:30 — Robotics Block 2: Tune the Gain

Change only GAIN, run, record. Too low drifts, too high wobbles; lower DRIVE_SPEED if needed. Milestone: smooth-ish follow.

  • Objective: tune GAIN until the line-follow is smooth.
  • Flow:
    1. Change only GAIN, run, watch, record the behavior on the worksheet.
    2. Too low → sloppy/drifts off; too high → wobbles. Hunt for “just right.”
    3. If wobble persists, lower DRIVE_SPEED too — speed and gain interact.
    4. Stretch (older teams, if two color sensors are free): steer from the difference between a left and right sensor (follows the line’s center).
  • Watch for:
    • Teams changing GAIN, speed, and threshold at once — change one thing at a time
    • Frustration that it’s not perfectly smooth — “smooth-ish” is a win
    • Make sure the Tester is recording GAIN tries; that’s the day’s artifact
  • Tip: a piece of tape with curves and a straightaway shows tuning differences clearly.

11:30-12:00 — Showcase + Cleanup

Each team demos their best run of the week, then pack hubs and celebrate. Protect the showcase: hard stop, this is the finale.

  • Showcase: each team demos their best run of the entire week — a drive, a maze, a gyro turn, an obstacle dodge, or today’s line-follow.
  • Prompts:
    • “Show us your best run — what is it doing?”
    • “What’s one thing you tuned, and how did you know it worked?”
    • “What was your favorite mission this week?”
  • Cleanup: charge and pack the hubs.
  • Celebrate: recap the five missions and name what each team built. This is the finale.

General Tips Throughout

Calibrate (don’t memorize), tune one thing at a time, treat bugs as sensor data, rotate roles, and protect the showcase.

  • Calibrate, don’t memorize: never hand out “correct” BLACK/WHITE/GAIN numbers.
  • Follow the edge: say it out loud so the normal wobble doesn’t read as a fault.
  • Tune one thing at a time: GAIN is the whole lesson — change only it between runs.
  • Bugs are sensor data: when the robot misbehaves, ask “what did the code say?”
  • Everyone codes: rotate roles and keep the off-robot task going so all four stay engaged.
  • Protect the showcase: it’s the payoff for the week — hard stop at 11:30.