AARDUINO
FIELD NOTES
5-DAY MAKER COURSESUMMARY NOTES

Build it.
Code it.
Make it react.

From your first blinking LED to a complete smart farm—one clear pattern connects every project.

MAKER NAME
ARDUINOUNO
BRAIN
USB
01 INPUT
02 CODE
03 OUTPUT
THE UNIVERSAL PATTERNREAD sensor→IF condition→REACT output
YOUR ROADMAP

Five days. One system.

Each day adds one new superpower. By Day 5, you combine them all.

DAY 01●

Arduino Basics

LED Blink

↘DAY 02♪

Inputs & Sound

Piezo Piano

↘DAY 03⌁

Sensors

Light & Distance

↘DAY 04!

Security

PIR Alarm

↘DAY 05✦

Smart Farm

Final Project

↘
01
DAY ONE

Arduino Basics & LED Blink

ArduinoBreadboardLEDdigitalWritedelay
01

Physical computing

INPUTswitch→BRAINmainboard→OUTPUTmotor

Arduino UNO is a tiny computer—the brain inside robots, drones, and 3D printers.

02

Complete the loop

5V +→PARTS→GND −

Electricity must travel in a full loop. One break anywhere means nothing works.

03

Know your parts

  • BreadboardPower rails run horizontally; terminal groups connect vertically in sets of five.
  • LEDLong leg is positive (+), short leg is negative (−). Direction matters.
  • 220Ω resistorProtects the LED. Never skip it.
WORK ORDER1 Build the circuit →2 Write the code →3 Upload
blink.inoARDUINO · C++
void setup() {
  pinMode(13, OUTPUT);   // Pin 13 = output mode
}

void loop() {
  digitalWrite(13, HIGH); // LED ON
  delay(1000);            // wait 1 second
  digitalWrite(13, LOW);  // LED OFF
  delay(1000);            // wait 1 second
}
CODE IN PLAIN ENGLISH

setup() runs once.

loop() repeats forever.

delay(1000) = 1000 ms = 1 second.

MISSION CHECK
  • Blink every 0.5 seconds. Hint: delay(???)
  • Bonus: blink 3 times fast, then rest 1 second.
⚠POWER FIRST, WIRES SECOND

Turn OFF the board before connecting wires.

02
DAY TWO

LED Patterns & Piezo Piano

INPUTdigitalReadiftonebuzzer
FROM TALKING TO LISTENING

Arduino gets an input.

OUTPUTArduino talksLED · buzzer
+
INPUTArduino listensbutton · sensor

A button is the simplest input. Pressing it lets electricity flow. Use a 10KΩ resistor.

if means: “do this only when the condition is true.”
PIEZO NOTE FREQUENCIES

Higher number = higher sound

262DO
294RE
330MI
349FA
392SOL

tone(pin, frequency, duration)

button_buzzer.inoARDUINO · C++
void setup() {
  pinMode(12, OUTPUT);  // buzzer
  pinMode(9, INPUT);    // button
}

void loop() {
  if (digitalRead(9) == HIGH) {  // button pressed?
    tone(12, 330, 200);          // play sound
  }
  noTone(12);
}
MISSION CHECK
  • All 3 LEDs: ON 0.5s, OFF 0.5s.
  • Turn LEDs on one by one like a wave.
  • Build a piano with 5 buttons—one note each.
  • Bonus: play “Happy Birthday”!
3 LEDs = 3 pinsWrite pinMode three times: pins 13, 12, and 11.
03
DAY THREE

Sensors Ultrasonic & Light

SensorUltrasonicSerial MonitoranalogReadLDR
⌁
HC-SR04

See with sound.

Like a bat: send a sound, wait for its echo, then calculate distance.

distance = time × speed of sound ÷ 2
☀
LDR

Measure the light.

Bright → BIG number
Dark → small number

01023
›_
SERIAL MONITOR

Hear Arduino talk.

Serial.begin(9600) starts talking. Serial.println(x) shows the value.

auto_light.inoARDUINO · C++
int light;

void setup() {
  pinMode(13, OUTPUT);       // LED
  Serial.begin(9600);
}

void loop() {
  light = analogRead(A0);    // read light (0~1023)
  Serial.println(light);
  if (light < 300) {         // dark?
    digitalWrite(13, HIGH);  // LED ON
  } else {
    digitalWrite(13, LOW);   // LED OFF
  }
  delay(200);
}
ULTRASONIC WIRING
VCC
5V
TRIG
PIN 9
ECHO
PIN 8
GND
GND
MISSION CHECK
  • Move your hand near the sensor—watch the number change.
  • Cover the LDR—the LED turns ON.
  • Dark → buzzer beeps.
  • Bonus: hand closer than 10 cm → LED ON.
SMART HOME LOGICIF it is dark→turn on the light
04
DAY FOUR

Security System PIR Alarm

PIRMotionAlarmDeploy
HUMAN
HEAT
PASSIVE INFRARED

PIR sees heat change.

Humans give off heat. When a person moves, the PIR sends HIGH. No motion means LOW—just like a button.

DETECT+ALERT= SECURITY SYSTEM
pir_alarm.inoARDUINO · C++
void setup() {
  pinMode(7, INPUT);     // PIR
  pinMode(13, OUTPUT);   // LED
  pinMode(12, OUTPUT);   // buzzer
}

void loop() {
  if (digitalRead(7) == HIGH) {
    digitalWrite(13, HIGH);
    tone(12, 988, 300);      // alarm sound!
    delay(300);
    tone(12, 660, 300);
    delay(300);
  } else {
    digitalWrite(13, LOW);
    noTone(12);
  }
}
PIR WIRING · ONLY 3 WIRES
VCC
5V
OUT
PIN 7
GND
GND
MISSION CHECK
  • Wave your hand → LED ON.
  • Change frequency and speed—make the alarm yours.
  • Bonus: blink the LED fast while the alarm rings.
  • Install it at the entrance and test it.
◷LET THE SENSOR WAKE UP

PIR needs 30–60 seconds of warm-up after power ON.

05
DAY FIVE · FINAL PROJECT

Smart Farm Full System

Soil MoistureRelayPumpFull System
THE PROBLEM

Plants can’t ask for water.
So we help them speak.

The sensor watches the soil 24/7. When dry, Arduino tells a relay to power the pump.

READSOILdry = BIG
→
DECIDEARDUINOsoil > 600?
→
REACTPUMPwater flows
↯
WHY A RELAY?

A small signal controls big power.

The pump needs more power than an Arduino pin can provide. Arduino is the boss; the relay is the strong worker. You can hear it click.

Pump power comes from the battery, never from the Arduino pin.
BUILD PLAN1 · BUILD→2 · TEST→3 · COMBINETest each part before combining.
STEP 01

Find your dry number

Compare readings in dry and wet soil. Your threshold will be unique.

MY DRY NUMBER
soil_read.inoARDUINO · C++
int soil;

void setup() {
  Serial.begin(9600);
}

void loop() {
  soil = analogRead(A0);    // read soil moisture
  Serial.println(soil);
  delay(500);
}
STEP 02

Test the pump alone

Same logic as Blink—just a pump instead of an LED. If ON/OFF is reversed, swap HIGH and LOW.

pump_test.inoARDUINO · C++
int pump = 6;

void setup() {
  pinMode(pump, OUTPUT);
}

void loop() {
  digitalWrite(pump, HIGH);  // pump ON
  delay(3000);
  digitalWrite(pump, LOW);   // pump OFF
  delay(3000);
}
STEP 03

Combine the full system

Soil controls the pump. Tank level controls the warning LED.

smart_farm.inoARDUINO · C++
int soil;
int pump = 6;
long duration;
int distance;

void setup() {
  pinMode(pump, OUTPUT);
  pinMode(9, OUTPUT);    // Trig
  pinMode(8, INPUT);     // Echo
  pinMode(13, OUTPUT);   // warning LED
  Serial.begin(9600);
}

void loop() {
  // STEP 1: soil -> pump
  soil = analogRead(A0);
  if (soil > 600) {            // dry? use YOUR number!
    digitalWrite(pump, HIGH);
  } else {
    digitalWrite(pump, LOW);
  }

  // STEP 2: tank level -> warning LED
  digitalWrite(9, LOW);  delayMicroseconds(2);
  digitalWrite(9, HIGH); delayMicroseconds(10);
  digitalWrite(9, LOW);
  duration = pulseIn(8, HIGH);
  distance = duration * 0.034 / 2;

  if (distance > 15) {         // water low?
    digitalWrite(13, HIGH);    // warning!
  } else {
    digitalWrite(13, LOW);
  }

  Serial.print("Soil: ");  Serial.print(soil);
  Serial.print("  Tank: "); Serial.println(distance);
  delay(500);
}
PIN MAP · CHECK BEFORE POWER ON
PARTPIN
Soil sensorA0
Relay / pump6
Ultrasonic Trig9
Ultrasonic Echo8
Warning LED13
Optional servo5
RELAY + PUMP WIRING

SIGNAL SIDE

IN → Pin 6 · VCC → 5V · GND → GND

POWER SIDE

Battery (+) → COM · NO → Pump (+)
Pump (−) → Battery (−)

All GNDs connect together.
“GND is one family.”
OPTIONAL

“Water Me!” servo sign

Servo moves from 0°–180°. Dry soil raises a paper sign. Use Pin 5 because Pin 6 is taken.

myservo.attach(5);
MISSION CHECK
  • Dry soil → pump ON.
  • Empty the tank → warning LED ON.
≋WATER + ELECTRONICS

Keep them separated. Keep the pump underwater while running—never run it dry.

THE BIG PICTURE

Five days.
One pattern.

READ sensor→IF condition→REACT output
DAYREADIFREACT
01——LED blink
02buttonpressed?buzzer sound
03light / distancedark? close?LED / buzzer
04PIR motionmotion?alarm
05soil + tankdry? low?pump + warning

Every smart device in the world uses this pattern.

You are makers now.
Keep making.

↗