MISSION 11 · INTERMEDIATE ARDUINO
Turn a simple threshold into a target zone and challenge a friend.
3 · Give It a Rule
Your new skill: Turn a single threshold into a bounded range.
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.
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.
This sensor sends a pulse of sound too high for us to hear and times the returning echo to estimate distance.
Look for: Find the two round sound openings and labelled VCC, Trig, Echo and GND pins.
Before using it: Use the matching 5V Uno wiring. Soft or angled targets may not return a good echo; a missing echo is not zero distance.
Your turn: Choose a flat cardboard target and show where you will measure its distance with a ruler.
A ruler measures distance. A timer measures elapsed time. Your paper records a prediction and result so you can compare tests.
Look for: Find the cm marks or the timer display and a place to draw or write.
Before using it: Use the same start point and method each time. You can say, point or draw your evidence instead of writing long answers.
Your turn: Choose the mark where the first measurement will begin.
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. 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. HC SR04 ultrasonic sensor. This sensor sends a pulse of sound too high for us to hear and times the returning echo to estimate distance. Find the two round sound openings and labelled VCC, Trig, Echo and GND pins. Use the matching 5V Uno wiring. Soft or angled targets may not return a good echo; a missing echo is not zero distance. Ruler timer and evidence sheet. A ruler measures distance. A timer measures elapsed time. Your paper records a prediction and result so you can compare tests. Find the cm marks or the timer display and a place to draw or write. Use the same start point and method each time. You can say, point or draw your evidence instead of writing long answers. 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
Turn a single threshold into a bounded range.
You have just practised combine two independently tested inputs. Now: turn a single threshold into a bounded range.
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. HC-SR04 labelled VCC → 5V, GND → GND, TRIG → D9, ECHO → D10. Use this map only with the 5V Uno and the labelled HC-SR04; stop if the sensor differs.
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 TRIG_PIN=9,ECHO_PIN=10;int nearCm=20;
long readCm(){digitalWrite(TRIG_PIN,LOW);delayMicroseconds(2);digitalWrite(TRIG_PIN,HIGH);delayMicroseconds(10);digitalWrite(TRIG_PIN,LOW);unsigned long us=pulseIn(ECHO_PIN,HIGH,30000);return us==0?-1:long(us/58);}
void setup(){pinMode(LED_PIN,OUTPUT);pinMode(TRIG_PIN,OUTPUT);pinMode(ECHO_PIN,INPUT);Serial.begin(9600);}
void loop(){long cm=readCm();if(cm<0){Serial.println("No echo");digitalWrite(LED_PIN,LOW);}else{Serial.println(cm);digitalWrite(LED_PIN,cm>=nearCm-3 && cm<=nearCm+3);}delay(100);}
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, HC-SR04 sensor, Flat cardboard target, Household ruler. 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, HC-SR04 sensor, Flat cardboard target, Household ruler. An adult identifies the component pins from their printed labels. Unplug USB before building.
WHAT'S REALLY HAPPENING?
A range has a lower and upper limit. The program combines two comparisons; measurement noise means the boundary may not be perfectly steady.
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
Adapt one tested program and demonstrate its limits.