Learning Goals 5 min
The final lesson. You take a 20-question rehearsal under timed conditions, score yourself, and write a personal revision plan for the days before the real exam. By the end of this lesson you will:
- Complete a timed 20-question mock exam (40 minutes).
- Score yourself + identify weak domains.
- Have a written, day-by-day study plan for the week leading to your real exam.
Warm-Up 5 min
Quiet space. No phone. Set a timer for 40 minutes. Pen + paper for working out. No looking at the lesson contents during the mock.
The real exam is 36 questions in 75 minutes (~2 minutes each). This mock is 20 in 40 minutes — same per-question pacing.
The Mock Exam — 20 questions, 40 minutes 40 min
Don't look at the answers until you've completed all 20. Mark your answers (1, 2, 3, 4) on a piece of paper as you go.
Total resistance: 220 Ω + 330 Ω in series.
- 110 Ω
- 132 Ω
- 550 Ω
- 1100 Ω
The Arduino IDE's Serial Monitor expects what default baud rate?
- 300
- 9600
- 115200
- 1200
Which Arduino pin can NOT be used as an external interrupt on an UNO?
- D2
- D3
- D5
int x = 5;
int y = x++;
int z = ++x;
Serial.print(x); Serial.print(" "); Serial.print(y); Serial.print(" "); Serial.println(z);Output?
- 5 5 6
- 7 5 7
- 6 5 7
- 6 6 7
The on-board LED of an Arduino UNO is on which pin?
- 11
- 12
- 13
- 10
Which is the I²C clock line?
- SDA
- MOSI
- SCL
- CS
An LED has VF = 2 V; we drive at 20 mA from 5 V. Resistor?
- 50 Ω
- 100 Ω
- 150 Ω
- 220 Ω
How many bytes is an int on a standard UNO?
- 1
- 2
- 4
- 8
To make a pin an output pin:
digitalWrite(pin, OUTPUT)pinMode(pin, OUTPUT)setOutput(pin)pinMode(pin, HIGH)
The reset button on an Arduino:
- Clears flash
- Restarts the sketch
- Disconnects power
- Connects to WiFi
The Arduino setup() function runs:
- Once at boot
- Repeatedly forever
- Only on USB power
- Every interrupt
Flyback diode polarity (across a motor):
- Anode at V+, cathode at motor−
- Cathode at V+, anode at motor−
- Diode wired in series with the motor
- Diode wired in series with the supply
What does millis() return?
- Microseconds since boot
- Milliseconds since boot
- Seconds since 1970
- Random number 0-1000
The minimum components to debounce a button in software:
- A timer (millis) check between presses
- An extra resistor
- A capacitor across the button
- None — buttons don't bounce
What does PWM stand for?
- Pulse Width Modulation
- Power Wave Mode
- Programmable Wire Module
- Periodic Wide Manager
An NPN transistor with 0 V on its base behaves like:
- A short
- An open switch
- A diode
- A resistor
For an HC-SR04 ultrasonic sensor with timing pulse 1160 µs:
- ~10 cm
- ~20 cm
- ~50 cm
- ~5 cm
A correct way to write a non-blocking 1-second blink in loop():
- delay(1000); toggle;
- Use millis() to check elapsed time since last toggle, then toggle if >= 1000.
- Use a busy-wait loop counting milliseconds.
- Trigger an interrupt every loop.
Which board has built-in WiFi + Bluetooth?
- UNO R3
- Nano (V3)
- Nano ESP32
- Mega 2560
The simplest controller for keeping a fridge at 4 °C is:
- PID
- Bang-bang with hysteresis
- Open loop
- Kalman filter
Answer key
Reveal all answers
| Q | Answer | Why |
|---|---|---|
| 1 | 3 (550 Ω) | Series: R1 + R2. |
| 2 | 2 (9600) | Historical default. Some boards use 115200. |
| 3 | 3 (D5) | UNO interrupts on D2 + D3 only. |
| 4 | 2 (7 5 7) | x++ post-increments; ++x pre-increments. x=5→6→7; y=5; z=7. |
| 5 | 3 (13) | UNO LED_BUILTIN = D13. |
| 6 | 3 (SCL) | SCL = clock; SDA = data. |
| 7 | 3 (150 Ω) | R = (5−2)/0.02 = 150 Ω. |
| 8 | 2 (2) | UNO int is 16-bit. |
| 9 | 2 | pinMode + OUTPUT. |
| 10 | 2 | Restart from setup(). |
| 11 | 1 | Once at boot. |
| 12 | 1 | Cathode (line) to motor+ side; anode (triangle) to motor− side. Wait — the question says "Anode at V+" — that's reverse-biased properly: cathode goes to V+, anode to the transistor / motor− side. Re-read: Q12 option 1 says "Anode at V+" — that's WRONG. Option 2: "Cathode at V+, anode at motor−": this is correct (reverse-biased during normal operation, captures kick on switch-off). Answer: 2. |
| 13 | 2 | millis() = ms since boot. |
| 14 | 1 | Software: millis()-based debounce. |
| 15 | 1 | Pulse Width Modulation. |
| 16 | 2 | NPN with 0 V base = off = open switch. |
| 17 | 2 (~20 cm) | cm = (pulse_µs × 0.0343) / 2 = 1160 × 0.0343 / 2 ≈ 19.9 cm. |
| 18 | 2 | millis() pattern. |
| 19 | 3 (Nano ESP32) | ESP32 has both. |
| 20 | 2 | Bang-bang + hysteresis is correct for a fridge — simple, cheap, on/off compressor + temperature deadband. |
Score yourself
- 17-20 right: excellent. You're ready. Light revision only.
- 13-16 right: solid pass likely. Targeted revision per missed question.
- 9-12 right: borderline. Spend a week revisiting weak domains.
- < 9 right: more revision needed. Re-read L01-L04 capstones. Re-do their mini-challenges.
Worked Example · Your personal study plan 15 min
Open your notebook to a fresh page. Title: "Arduino Cert · <exam date>".
Step 1 — schedule
Pick a target exam date in 1-3 weeks. Calendar slots: 30 minutes per day.
Step 2 — weak-spot list
From the mock + L04-46/47 quizzes, list domains you scored < 70% on.
Step 3 — daily plan
| Day | Focus | Output |
|---|---|---|
| Day 1 / weak domain A | Re-read lessons covering A | Notes on key formulas / patterns |
| Day 2 / weak domain B | Re-do TIY tasks from those lessons | Working sketch |
| Day 3 / weak domain C | Re-read + practice questions | 5 sample Qs you write yourself |
| Day 4 | Mixed-domain self-quiz | 20 questions in 40 min |
| Day 5 | Full retake of this lesson's mock | Score |
| Day 6 | Sleep, light review only. | — |
| Exam day | Warm coffee, calm. | Cert. |
Step 4 — backup plan
If you fail, retake. Most certs allow at least one retake. After failure, identify which domains lost points; spend 1 week on those before re-sitting.
Step 5 — celebrate when you pass
The Arduino Certificate is a real credential. Add to your LinkedIn / portfolio / college applications. Worth flagging.
Final Recap 15 min
You finished the 4-level Arduino programme.
What you can now do
- Light an LED, read a button, blink in patterns (L01).
- Drive sensors, analogue inputs, LCDs, EEPROM, SD cards (L02).
- Servos, DC motors, steppers, H-bridges (L03 Cluster A–C).
- UART, I²C, SPI protocols + OLED + shift registers (L03 Cluster D).
- Bluetooth Classic + BLE + WiFi web server / client / IoT cloud (L03 Cluster E–G, L04 Cluster B–C).
- OOP + reusable code + your own libraries (L03 Cluster H, L04 Cluster H).
- LoRa / Modbus / CAN industrial protocols (L04 Cluster D).
- Closed-loop control, PID, self-balancing robot (L04 Cluster E).
- Edge AI: gesture recognition on a microcontroller (L04 Cluster F).
- Battery / solar low-power IoT nodes (L04 Cluster G).
- Publishing libraries to the Arduino registry (L04 Cluster H).
- The vocabulary + pattern recognition for the Certification exam (L04 Cluster I).
Where to go next
- Take the exam. Earn the cert.
- Submit at least one library to the Library Registry. Open source.
- Build a more ambitious project: drone, robot dog, weather station network, plant farm.
- Pick up Python / Linux on Raspberry Pi for the "bigger" embedded path.
- Learn FPGAs / digital design for the deep-hardware path.
- Apply for engineering internships citing your portfolio of projects.
Congratulations. 192 lessons across 4 levels, every protocol, every cluster — done. You're no longer learning Arduino. You're an Arduino engineer.
- Mock exam
- A timed practice run under conditions similar to the real exam. The single best predictor of real performance.
- Study plan
- A day-by-day schedule allocating revision time to specific topics. Beats "I'll study sometime".
- Weak-spot list
- The domains where mock scores are lowest. Where your revision time has the highest return.
- Retake policy
- Most certs allow one retake; further attempts paid. Plan for it but don't aim for it.
Homework 5 min
- Score the mock. Note which questions you missed.
- Write your study plan.
- Book the exam.
- Pass.
That's the end of the 192-lesson Arduino journey. Whatever you build next, send a picture — your former teachers will be cheering you on. 👋