Arduino Uno R3

Tilt to event

Turn a tilt-switch change into a stable, observable event rather than treating orientation as a guaranteed continuous measurement.

CSTA 2026 mapping candidatesNot reviewed by CSTA

MS-PRO-TR-19Programming

Students will

Read a tilt switch with a defined resting state
Distinguish a held state from a change of state
Test orientation and vibration limits

Evidence of success

Stable orientations produce repeatable readings
The sketch reports transitions separately from held states
The student identifies vibration as a possible source of extra transitions

Hardware

Arduino Uno R3
Tilt switch from the Starter Kit
Breadboard and jumper wires

Prerequisites

Read a reliable digital input
Open Serial Monitor

Before class

Verify the actual switch closes in at least one orientation
Prepare a stable mounting method
Explain that the switch reports contact, not an angle

Reviewed connection map

Tilt switch input

D8 INPUT_PULLUPStable digital input

Tilt switchContact opens or closes with orientation

GNDClosed contact reads LOW

Connect the verified tilt switch between D8 and GND.
Secure it so deliberate orientation changes can be distinguished from vibration.

Build and test

01Connect the tilt switch between D8 and GND
02Configure D8 with INPUT_PULLUP
03Observe the state in several stable orientations
04Detect and print only changes from the previous state
05Repeat ten controlled tilts and record false or repeated events

Read before uploading

Annotated Arduino sketch

const int TILT_PIN = 8;
bool previousState;

void setup() {
  pinMode(TILT_PIN, INPUT_PULLUP);
  Serial.begin(9600);
  previousState = digitalRead(TILT_PIN);
}

void loop() {
  bool currentState = digitalRead(TILT_PIN);
  if (currentState != previousState) {
    Serial.println(currentState == LOW ? "contact closed" : "contact open");
    previousState = currentState;
    delay(30);
  }
}

Optional engineering record

Record evidence from this lesson

Choose the prompts that help students explain predictions, evidence, debugging, and transfer. Saving creates a new entry in this browser’s Rudi notebook.

Record your thinking — optional4 prompts

Use these prompts if they help students capture evidence, decisions, or questions. You do not need to complete every prompt or create an entry at every step.

Predict: Before you begin, what do you expect to observe when you read a tilt switch with a defined resting state?Evidence: What evidence best demonstrates this result: Stable orientations produce repeatable readings?Debug: If you encounter “Many events occur during one movement,” what will you check first, and why?Transfer: Where could you reuse the skill from “Tilt to event” in another classroom project?

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Troubleshooting

Many events occur during one movement

Mount the sensor securely and add a short settling interval after a detected change.

No orientation changes the reading

Verify the switch legs, breadboard rows, INPUT_PULLUP setting, and D8-to-GND path.

2026 middle school standards

Potential CSTA connections

Not reviewed by CSTA

These are evidence-based crosswalk candidates for curriculum review—not a claim of official alignment.

MS-PRO-TR-19

Use systematic strategies to test, refine, and document changes to a computing technology to meet the intended purpose.

Students isolate variables, compare observed behavior with the intended purpose, and document a revision.

Lesson evidence: Orientation and repeated-event test

View the official 2026 CSTA standardsStandard text: Computer Science Teachers Association (2026), CC BY-NC-SA 4.0.

Supporting concepts

floating-inputs · component-boards

Sources and review

Arduino Uno R3 documentation Arduino Projects Book · CC BY-NC-SA 3.0

Starting point, not verified curriculum. Review the actual hardware, circuit, code, power requirements, and classroom conditions.

After teaching this lesson