Arduino Decoder Worksheet
Arduino Decoder: Hardware & Circuits
Independent STEM Lab Worksheet • No Physical Hardware Needed
UNIT: EMBEDDED C & CIRCUITS
Student Name:
Date:
Class Period:
PART 1
Arduino Board Anatomy & Core Components
(10 Minutes)
Match each numbered feature of the Arduino Uno architecture to its correct operational description. Write the corresponding letter in the blank box.
Board Pins & Components
1. Digital Pins (0–13)
2. 5V & 3.3V Pins
3. GND (Ground) Pins
4. Analog IN (A0–A5)
5. Reset Button
Functional Descriptions
A. Completes electrical circuits by acting as the 0V reference return path.
B. Pins capable of sending or sensing binary states: HIGH (5V) or LOW (0V).
C. Re-starts the running code from the very first line of setup().
D. Provides constant positive electrical power to sensors, modules, and chips.
E. Reads variable voltage levels (0V–5V) from sensors like photoresistors and dials.
PART 2
Breadboard Wiring & Component Rules
(15 Minutes)
1. Breadboard Connection Layout
Explain the difference between how pins are connected internally along the Power Rails (+ / -) on the sides versus the Terminal Rows (1–30) in the center:
2. LED Anode vs. Cathode
An LED is a polarized diode. Which leg must connect to positive voltage (anode), and which feature on the LED bulb casing indicates the negative cathode?
3. Complete Circuit Trace Scenario
A student constructs a circuit: A jumper wire runs from Digital Pin 9 to a 220Ω resistor, through the resistor to the long leg (anode) of a red LED. The short leg (cathode) connects to a jumper wire going back to an Arduino GND pin.
A. Current Limiter: Why is the 220Ω resistor required? What happens without it?
B. Logic State HIGH: When Pin 9 is set to HIGH, what exact voltage is sent to the circuit?
C. Open vs Closed: If the wire at GND is pulled out, is the circuit open or closed? Does LED light?
Arduino Fundamentals • Substitute Classroom Mission Packet PAGE 1 OF 2 • CONTINUE TO CODE DECODER →
Arduino Decoder: Code Reading & Logic
PAGE 2 OF 2
PART 3
Sketch Code Analysis & Timing Trace
(15 Minutes)
Examine the Arduino C++ sketch below. Read every line carefully to understand how the microcontroller executes instructions from top to bottom.
FILE: beacon_alert.ino // Microcontroller Sketch
01const int ledRed = 10;
02const int buzzer = 6;
03
04void setup() {
05 pinMode(ledRed, OUTPUT);
06 pinMode(buzzer, OUTPUT);
07}
08
09void loop() {
10 digitalWrite(ledRed, HIGH);
11 digitalWrite(buzzer, LOW);
12 delay(2000);
13 digitalWrite(ledRed, LOW);
14 digitalWrite(buzzer, HIGH);
15 delay(1000);
16}
1. Setup vs Loop Function: How many times does setup() run compared to loop()?
2. Delay Unit Conversion: What unit of time does delay(2000) use, and how many whole seconds is that?
3. Pin Mode Role: Why must OUTPUT be specified in line 05?
Timeline Execution Trace (Fill in ON or OFF for each phase) Total Cycle Time = 3.0 Seconds
| Time Interval | Line Executing | Red LED (Pin 10) | Buzzer (Pin 6) |
|---|
| 0.0s – 2.0s (first 2000ms) | Lines 10 – 12 | | |
| 2.0s – 3.0s (next 1000ms) | Lines 13 – 15 | | |
| At 3.01 seconds... | End of loop() | What does the microcontroller do next? Describe in one phrase: ____________________ | |
PART 4
The Sub Bug Hunt: Spot 3 Syntax Errors
(10 Minutes)
pinmode(9, OUTPUT);
Bug #1: Capitalization
Why will this fail to compile? What is correct syntax?
digitalWrite(13 HIGH);
Bug #2: Punctuation
What specific character is missing between parameters?
delay(500)
Bug #3: Line Terminator
What required symbol is missing at the end of this line?
PART 5
Exit Ticket: Engineering Synthesis
(5 Minutes)
Design Challenge Prompt: Write 2–3 clear sentences
Suppose you want an LED to blink faster (e.g., rapid strobe warning light). Exactly which function in the code must you modify, what parameter change would you make, and why does that change work?
Turn this completed worksheet into the substitute teacher before class dismissal. ARDUINO EMBEDDED LAB #01 • COMPLETE
