AP CSP 1.2 Exercise 2: Trigger Tracer

Big Idea 1 · Topic 1.2 · Exercise 2

Trigger Tracer

25 minutes - 4 traces - LO CRD-2.C, CRD-2.D

Back to the Topic 1.2 lessonAll CSP topics

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The same cases as your handout, in the same order.

Scenario 1 · Foundational

At a crosswalk, a pedestrian presses the metal button. The controller program lights the WALK symbol and plays a chirping tone for pedestrians who can't see the signal. Between presses, the crosswalk program keeps running the normal traffic-light cycle.

Inputs and outputs traced (source, form, destination):

Execution model + trigger (sequential or event-driven, and why):

Prior-state layer (enrichment):

Scenario 2 · Core

Every night at 2:00 a.m., the district gradebook software transmits the day's grades to the student portal program. The portal recalculates each student's average and emails a summary to families who turned on notifications. No person is awake, and nothing appears on any screen.

Inputs and outputs traced (source, form, destination):

Execution model + trigger (sequential or event-driven, and why):

Prior-state layer (enrichment):

Scenario 3 · Core

A smart doorbell detects motion on the porch. Its program records a 10-second clip, sends a notification to the homeowner's phone, and - only when the household set 'night mode' earlier that evening - also switches on the porch spotlight. The same raccoon at 2 p.m. gets no spotlight.

Inputs and outputs traced (source, form, destination):

Execution model + trigger (sequential or event-driven, and why):

Prior-state layer (enrichment):

Scenario 4 · Challenge

In a rhythm game, a streaming server delivers each week's new song data to the game. During play, the player taps falling notes on the touchscreen; hits make the phone flash the note, buzz briefly, and raise a combo multiplier that makes later notes worth more. Two players tapping identical patterns can end with different scores if one started the song with a 'streak bonus' from yesterday.

Inputs and outputs traced (source, form, destination):

Execution model + trigger (sequential or event-driven, and why):

Prior-state layer (enrichment):

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