31. College Practical Assessments

How assessment works on this course

Each practical is marked with its own criteria grid. Open the rubric before you start so you know what evidence is required. Use Print / Save as PDF from the rubric page if you need a paper copy.

Workflow for every task: read the brief; list success criteria; draw IPO / block diagram; prepare a pin table and power note; build and test modules; integrate; fill the test table; submit portfolio items listed on the rubric.

Evidence every assessor expects

Software that 'mostly works' is not enough. Across Tasks A-C you should be able to show:

1. Planning artefacts produced before energising 2. Safe wiring (series resistors, common GND, drivers for heavy loads) 3. A test table: condition, expected, measured/observed, pass/fail 4. At least one fault found and how you fixed it 5. A short explanation of decisions (oral or written)

Use Lesson 25 fault-finding habits: measure, do not randomly rewire.

Practical Task A - Two-button controller

Brief: two debounced buttons select three distinct LED/PWM output states. Serial reports each state change. Submit a truth table that matches the demo.

Suggested course pins: button A on D2 to GND (INPUT_PULLUP), button B on D3 to GND, status LED on D5, PWM LED on D6. Name your own pins in the pin table if the brief differs.

Marking emphasises debounce quality, agreement between truth table and behaviour, and clean Serial messages (no flood while a button is held).

Practical Task B - Sensor alarm

Brief: read one analogue sensor, display a calibrated engineering value, and drive an alarm through safe hardware. Use hysteresis (separate on and off thresholds) so the alarm does not chatter.

Choose a sensor you already practised (potentiometer, LDR, thermistor, etc.). Document the conversion formula or calibration points before the final demo. If the alarm load needs more current than a pin can supply, use a driver (lesson 12).

Practical Task C - Integrated system

Brief: combine an I2C display, one digital input/sensor, one analogue sensor and one actuator. Keep the system responsive with non-blocking timing (millis).

Prove each subsystem alone, then merge. Watch pin conflicts: I2C uses A4/A5 on the Uno. Success criteria must be written before the end-to-end demo; the rubric checks that you met every criterion.

Code-correction exercise

You are given a faulty sketch (use the downloadable faulty starter below, or a lecturer variant). Find and repair every defect, then explain these classes:

- Capitalisation / identifiers (pinMode vs PinMode, Serial vs serial) - Pin modes that match the wiring - Comparison == versus assignment = - Matching braces - Required semicolons

Attempt the repair before opening the fixed reference sketch on this page. The rubric marks your inventory and explanation, not only a compiling file.

// FAULTY STARTER - repair before comparing to the fixed reference.
byte InputPin = 2;
byte outputPin = 13;

void setup() {
  PinMode(InputPin, INPUT);
  pinMode(outputPin, OUTPUT)
  Serial.begin(9600);
}

void loop() {
  if (digitalRead(InputPin) = LOW) {
    digitalWrite(outputPin, HIGH);
  else {
    digitalWrite(outputPin, LOW);
  }
}

How the criteria grid is marked

Each rubric is a full matrix for that assessment. Rows cover planning, code, hardware, diagram, I/O, BOM/safety, testing, resolved challenges, unresolved challenges and explanation as needed for the brief.

Four levels on every row (tick or circle one cell only): - Excellent - Proficient - Basic - Poor

There is no separate score column. Always use the rubric grid for the assessment you are sitting.

Wiring and safe build sequence

1. Before any task: labelled connection diagram, pin table and power note submitted or shown to the assessor
2. Common GND across Uno, modules and any external supply
3. Series resistors on LEDs; INPUT_PULLUP buttons to GND unless the brief specifies otherwise
4. Drivers and flyback protection for relays, motors, solenoids or heavy buzzers
5. Instructor or peer short-check before first power-up

What this sketch is for: Deliberately broken sketch for the code-correction assessment. Repair it, then compare with the fixed reference above.

// FAULTY STARTER - repair before comparing to the fixed reference.
byte InputPin = 2;
byte outputPin = 13;

void setup() {
  PinMode(InputPin, INPUT);
  pinMode(outputPin, OUTPUT)
  Serial.begin(9600);
}

void loop() {
  if (digitalRead(InputPin) = LOW) {
    digitalWrite(outputPin, HIGH);
  else {
    digitalWrite(outputPin, LOW);
  }
}