MISSION 09 · INTERMEDIATE ARDUINO
Teach the light to need two clues, then compare a different rule.
3 · Give It a Rule
Your new skill: Test all combinations of an AND and OR rule.
Revisit the skill you will reuse: Previous main-path mission
Match the names to your parts before you build. New parts appear when you first need them. You can point, say the name or show a grown-up.
This reusable building board joins some holes with hidden metal strips, so we can connect parts without soldering.
Look for: Find the centre gap, row numbers and power rails. The gap separates the two halves.
Before using it: Five holes in one numbered strip usually join; the strip across the gap does not. Some power rails have a break. Match your board diagram.
Your turn: Point to two holes on the same connected strip, then two that are separated by the gap.
A wire makes an electrical connection between two points. A clip lead grips a terminal.
Look for: Jumpers have small plug ends; clip leads have metal jaws. Colour helps us track a connection.
Before using it: Colour does not change a wire's job. Check both ends and keep bare metal away from other terminals.
Your turn: Follow one wire from start to finish and name what it joins.
A resistor limits current in a path. Beside our LED it helps protect the light from too much current. Its resistance is measured in ohms.
Look for: Look for a small body with two legs and coloured bands; match its labelled value to the mission.
Before using it: A resistor can face either way. Values such as 1 kΩ and 10 kΩ are different: k means one thousand. Keep the specified value.
Your turn: Point to the resistor in the LED path. Explain why replacing it with a plain wire is not our test.
An LED turns electrical energy into light and works in one direction. We use it to show what a circuit is doing.
Look for: An untrimmed ordinary LED often has a longer anode leg and a shorter cathode leg. A flat rim often marks the cathode.
Before using it: Confirm polarity with the part card if legs are trimmed. Use the mission's resistor in series; never connect an LED straight across the battery.
Your turn: With power off, identify the two legs and point to its protective resistor.
A push button changes an electrical connection while you press it. It gives our circuit a short instruction.
Look for: Match the two-leg or four-leg part to the supplied card. It springs back when released.
Before using it: Our instructions specify the working pair of terminals. A four-leg button has internally joined pairs, so do not guess which pair switches.
Your turn: Press and release it without power. Predict which state will make our signal turn on.
An LDR is a resistor whose resistance changes with light. Our circuit uses that change as a clue about brightness.
Look for: Look for a little round face with a zigzag pattern and two legs.
Before using it: Do not guess whether a reading goes up or down: the circuit arrangement matters. Compare uncovered and shaded readings first.
Your turn: Point to the face you will shade without moving any wires.
This programmable board reads inputs and controls outputs by following a program called a sketch.
Look for: Find the USB socket, the labelled digital and analog pins, 5V and GND. The microcontroller is a small computer chip on the board.
Before using it: Our course uses the 5V Uno and USB supply. GND is the shared electrical reference, not a special part or an instruction to connect to a wall socket.
Your turn: Point to the built-in LED, a digital pin and an analog input pin without plugging in any wires.
The computer lets us write and upload a sketch. A USB data cable carries the upload and supplies the Uno in these missions.
Look for: Match the board socket and computer socket. Some cables charge only and cannot transfer a sketch.
Before using it: Use Arduino IDE and the selected Uno board and port. Disconnect USB before moving circuit wires.
Your turn: Find the upload button and the board selection before running the first sketch.
A video demonstration will appear here when it is ready. You can follow the written step now.
Before we build, match these names to the parts in front of you. Breadboard. This reusable building board joins some holes with hidden metal strips, so we can connect parts without soldering. Find the centre gap, row numbers and power rails. The gap separates the two halves. Five holes in one numbered strip usually join; the strip across the gap does not. Some power rails have a break. Match your board diagram. Jumper wire and clip lead. A wire makes an electrical connection between two points. A clip lead grips a terminal. Jumpers have small plug ends; clip leads have metal jaws. Colour helps us track a connection. Colour does not change a wire's job. Check both ends and keep bare metal away from other terminals. Resistor. A resistor limits current in a path. Beside our LED it helps protect the light from too much current. Its resistance is measured in ohms. Look for a small body with two legs and coloured bands; match its labelled value to the mission. A resistor can face either way. Values such as 1 kΩ and 10 kΩ are different: k means one thousand. Keep the specified value. LED or light emitting diode. An LED turns electrical energy into light and works in one direction. We use it to show what a circuit is doing. An untrimmed ordinary LED often has a longer anode leg and a shorter cathode leg. A flat rim often marks the cathode. Confirm polarity with the part card if legs are trimmed. Use the mission's resistor in series; never connect an LED straight across the battery. Push button. A push button changes an electrical connection while you press it. It gives our circuit a short instruction. Match the two-leg or four-leg part to the supplied card. It springs back when released. Our instructions specify the working pair of terminals. A four-leg button has internally joined pairs, so do not guess which pair switches. LDR or light dependent resistor. An LDR is a resistor whose resistance changes with light. Our circuit uses that change as a clue about brightness. Look for a little round face with a zigzag pattern and two legs. Do not guess whether a reading goes up or down: the circuit arrangement matters. Compare uncovered and shaded readings first. Arduino Uno. This programmable board reads inputs and controls outputs by following a program called a sketch. Find the USB socket, the labelled digital and analog pins, 5V and GND. The microcontroller is a small computer chip on the board. Our course uses the 5V Uno and USB supply. GND is the shared electrical reference, not a special part or an instruction to connect to a wall socket. USB data cable and computer. The computer lets us write and upload a sketch. A USB data cable carries the upload and supplies the Uno in these missions. Match the board socket and computer socket. Some cables charge only and cannot transfer a sketch. Use Arduino IDE and the selected Uno board and port. Disconnect USB before moving circuit wires. Pause and point to the part that will do the main job in this mission. If it is missing or looks different, ask a grown-up before building.
WHAT YOU'LL USE
Kit list: match the named parts to your box and its component cards. Home list: gather these before starting; some may also be supplied in your kit. Reuse components between missions. Stop and ask a grown-up if an essential part or label is missing.
BEFORE YOU BUILD
Disconnect USB before moving any wire. Use USB to power the Uno. Every separate LED needs its own 1 kΩ series resistor. Never connect a motor, servo, or unknown buzzer to an I/O pin. Keep liquids below and away from the board. An adult checks the wiring against the printed component labels before power is connected.
YOUR REWARD
PREDICT BEFORE YOU BEGIN
What will the output do when you change the input? Say, point or draw your prediction.
YOUR CHALLENGE
NEW POWER-UP
Test all combinations of an AND and OR rule.
You have just practised calibrate a sensor with a dry/damp comparison. Now: test all combinations of an and and or rule.
Each coloured strip is one connected group. Different numbered rows stay separate. This explains the board; use the mission’s exact connection reference for component positions. Check rail breaks on your supplied board.
With USB disconnected, connect D8 → 1 kΩ resistor → LED long leg (anode). Connect the LED short leg (cathode) → GND. Place the two LED legs on different connected strips; never put them in the same strip. Connect one LDR leg to 5V and the other to A0. Connect a 10 kΩ resistor from that same A0 strip to GND. This divider produces a higher reading in brighter light. The LDR has no polarity. Button terminals → D2 and GND. Reuse the measured threshold from your darkness mission.
Copy the complete code into Arduino IDE or download the sketch. Follow the matching component card before connecting power.
const byte LED_PIN=8;
const byte BUTTON_PIN=2,LIGHT_PIN=A0;int threshold=500;bool useAnd=true;
void setup(){pinMode(LED_PIN,OUTPUT);pinMode(BUTTON_PIN,INPUT_PULLUP);Serial.begin(9600);}
void loop(){bool pressed=digitalRead(BUTTON_PIN)==LOW,dark=analogRead(LIGHT_PIN)<threshold;bool result=useAnd?(pressed&&dark):(pressed||dark);digitalWrite(LED_PIN,result);Serial.print(pressed);Serial.print(" ");Serial.print(dark);Serial.print(" -> ");Serial.println(result);delay(150);}
BUILD PATH
STEP 1 OF 7
Lay out Arduino Uno, USB data cable, Computer with Arduino IDE, Breadboard, 1 LED, 1 × 1 kΩ resistor, Jumper wires, 2-leg push button, LDR, 1 × 10 kΩ resistor. An adult identifies the component pins from their printed labels. Unplug USB before building.
A video demonstration will appear here when it is ready. You can follow the written step now.
Lay out Arduino Uno, USB data cable, Computer with Arduino IDE, Breadboard, 1 LED, 1 × 1 kΩ resistor, Jumper wires, 2-leg push button, LDR, 1 × 10 kΩ resistor. An adult identifies the component pins from their printed labels. Unplug USB before building.
WHAT'S REALLY HAPPENING?
AND needs both conditions to be true. OR needs at least one. Recording all four combinations checks a rule more carefully than testing only its easiest case.
FAIR-TEST CHALLENGE
Change one feature, keep the rest the same and repeat your comparison.
CLEAN, RESET AND STORE
Disconnect USB before removing wires. Keep sensors dry. Recover and store the reusable parts.
NEXT SKILL
Combine two independently tested inputs.