Tinkercad and Arduino Tasks

Circuits

How to use the Tinkercad builds

Start with the screenshot so you know where the parts go.

Then wire the parts in the same order as the steps. Add the sketch last.

Use the picture first

Do not start with code if the wiring is not clear yet.

Name the pins

Write the pin numbers down while you wire them.

Test one thing

Check one LED, one sensor, or one motor before you test the full project.

LED Dice

LED Sequence Prototype

Motion Alarm with Buzzer and Servo

Running Lights with Potentiometer Control

Motion Alarm with LEDs

Two Blinking LEDs

Light-Controlled Motor Prototype

Motor Encoder Speed Reader

Railway Crossing Simulation

Motion Sensor with Servo Gate

Temperature Indicator with LEDs

Tinkercad

LED Dice

This is a fun starter circuit. It mixes button input, random numbers, and LED patterns.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Wire the LEDs to digital pins 2 to 8 through resistors.
Wire the push button to pin 9 and use INPUT_PULLUP in code.
Paste the sketch into Tinkercad Code or the Arduino IDE.
Press the button to roll a new number.

Parts

Arduino Uno
7 LEDs
7 resistors
1 push button
Breadboard and jumper wires

Quick test

Every button press should light one pattern from 1 to 6.
The LEDs should turn off before the next pattern is shown.

FILE: sketch.ino

sketch.ino

const int buttonPin = 9;

int leds[7] = {2, 3, 4, 5, 6, 7, 8};
// 0=LH, 1=PH, 2=LD, 3=PD, 4=STRED, 5=LS, 6=PS

int lastButtonState = 0;

void setup() {
  for (int i = 0; i < 7; i++) {
    pinMode(leds[i], OUTPUT);
  }

  pinMode(buttonPin, INPUT);
  randomSeed(analogRead(A0));
}

void loop() {

  int buttonState = digitalRead(buttonPin);

  if (buttonState == HIGH && lastButtonState == LOW) {
    int cislo = random(1, 7);
    zobrazCislo(cislo);
    delay(200);
  }

  lastButtonState = buttonState;
}

void zhasni() {
  for (int i = 0; i < 7; i++) {
    digitalWrite(leds[i], LOW);
  }
}

void zobrazCislo(int n) {

  zhasni();

  switch (n) {

    case 1: // střed
      digitalWrite(leds[4], HIGH);
      break;

    case 2: // levý horní + pravý dolní
      digitalWrite(leds[0], HIGH);
      digitalWrite(leds[3], HIGH);
      break;

    case 3: // levý horní + střed + pravý dolní
      digitalWrite(leds[0], HIGH);
      digitalWrite(leds[4], HIGH);
      digitalWrite(leds[3], HIGH);
      break;

    case 4: // všechny rohy
      digitalWrite(leds[0], HIGH);
      digitalWrite(leds[1], HIGH);
      digitalWrite(leds[2], HIGH);
      digitalWrite(leds[3], HIGH);
      break;

    case 5: // rohy + střed
      digitalWrite(leds[0], HIGH);
      digitalWrite(leds[1], HIGH);
      digitalWrite(leds[2], HIGH);
      digitalWrite(leds[3], HIGH);
      digitalWrite(leds[4], HIGH);
      break;

    case 6: // rohy + levý střed + pravý střed
      digitalWrite(leds[0], HIGH);
      digitalWrite(leds[1], HIGH);
      digitalWrite(leds[2], HIGH);
      digitalWrite(leds[3], HIGH);
      digitalWrite(leds[5], HIGH);
      digitalWrite(leds[6], HIGH);
      break;
  }
}

Tinkercad

LED Sequence Prototype

If you need one clear loop task in Tinkercad, this is a good choice.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Connect the LEDs to pins 2 to 6 through resistors.
Paste the code and start the simulation.
Watch the light move from left to right and back again.

Parts

Arduino Uno
5 LEDs
5 resistors
Breadboard

Quick test

The LEDs should turn on one after another, not all at once.
The direction should reverse after the last LED.

FILE: sketch.ino

sketch.ino

const int leds[] = {2, 3, 4, 5, 6};

void setup() {
  for (int i = 0; i < 5; i++) {
    pinMode(leds[i], OUTPUT);
  }
}

void loop() {
  for (int i = 0; i < 5; i++) {
    lightOne(i);
  }

  for (int i = 3; i > 0; i--) {
    lightOne(i);
  }
}

void lightOne(int index) {
  for (int i = 0; i < 5; i++) {
    digitalWrite(leds[i], i == index ? HIGH : LOW);
  }

  delay(180);
}

Tinkercad

Motion Alarm with Buzzer and Servo

This project mixes a sensor, an actuator, and a sound output in one build.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Connect the PIR output to pin 2.
Connect the buzzer to pin 8.
Connect the servo signal wire to pin 9.
Paste the code and start the simulation.
Trigger the PIR sensor to test the alarm.

Parts

Arduino Uno
PIR motion sensor
Piezo buzzer
Servo motor

Quick test

When motion is detected, the buzzer should beep and the servo should move.
When there is no motion, the buzzer should stop and the servo should return.

FILE: sketch.ino

sketch.ino

int pir_pin = 2;
int led_pin = 3;
int buzzer_pin = 4;
#include <Servo.h>     //zahrnutí knihovny pro ovládání servo motoru
Servo myservo;         //každý motor má svou instanci třídy Servo
int pos = 0;           //proměnná obsahující pozici motoru (úhel natočení)
void setup()
{
 pinMode(pir_pin, INPUT);
 pinMode(led_pin, OUTPUT);
 pinMode(buzzer_pin, OUTPUT);
   myservo.attach(7); 
 Serial.begin(9600);
  
}

void loop()
{
  if(digitalRead(pir_pin) == HIGH)
   {
  	digitalWrite(led_pin, HIGH);
    digitalWrite(buzzer_pin, HIGH);
    Serial.println("Detectado");
    for(pos = 0; pos <= 90; pos += 1) //je od úhlu 0 do úhlu 180
  {
    myservo.write(pos);  //natočení motoru na aktuální úhel
    delay(15);           //chvilka čekání než se motor natočí
  } 
   }
   else{
    digitalWrite(led_pin, LOW);
    digitalWrite(buzzer_pin, LOW);
    Serial.println("No Detectado");
     for(pos = 90; pos >= 0; pos -= 1) //je od úhlu 180 zpět do úhlu 0
  {
    myservo.write(pos);  //natočení motoru na aktuální úhel
    delay(15);           //chvilka čekání než se motor natočí

  }
   }
}

Tinkercad

Running Lights with Potentiometer Control

The potentiometer changes the timing, which makes this more useful than a fixed chaser.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Wire the LEDs to pins 2 to 5.
Wire the potentiometer middle pin to A0.
Read the analog value and map it to a delay range.
Run the sequence and adjust the knob.

Parts

Arduino Uno
4 LEDs
4 resistors
1 potentiometer

Quick test

Turning the potentiometer should change the speed.
The LED order should still stay the same.

FILE: sketch.ino

sketch.ino

const int leds[] = {2, 3, 4, 5};
const int potPin = A0;

void setup() {
  for (int i = 0; i < 4; i++) {
    pinMode(leds[i], OUTPUT);
  }
}

void loop() {
  int sensorValue = analogRead(potPin);
  int waitTime = map(sensorValue, 0, 1023, 60, 600);

  for (int i = 0; i < 4; i++) {
    digitalWrite(leds[i], HIGH);
    delay(waitTime);
    digitalWrite(leds[i], LOW);
  }
}

Tinkercad

Motion Alarm with LEDs

This is a lighter version of the buzzer-plus-servo alarm and is easier for beginners.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Wire the PIR to pin 2.
Wire the green LED to pin 8 and the red LED to pin 9.
Paste the sketch and start the simulation.
Trigger motion to swap the LED states.

Parts

Arduino Uno
PIR motion sensor
1 green LED
1 red LED
2 resistors

Quick test

No motion should show the green LED.
Motion should switch to the red LED.

FILE: sketch.ino

sketch.ino

const int pirPin = 2;
const int greenLed = 8;
const int redLed = 9;

void setup() {
  pinMode(pirPin, INPUT);
  pinMode(greenLed, OUTPUT);
  pinMode(redLed, OUTPUT);
}

void loop() {
  int motion = digitalRead(pirPin);

  if (motion == HIGH) {
    digitalWrite(redLed, HIGH);
    digitalWrite(greenLed, LOW);
  } else {
    digitalWrite(redLed, LOW);
    digitalWrite(greenLed, HIGH);
  }

  delay(100);
}

Tinkercad

Two Blinking LEDs

This is one of the fastest Arduino exercises to build and check.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Wire one LED to pin 2 and the other to pin 3.
Paste the sketch.
Run the simulation and watch them alternate.

Parts

Arduino Uno
2 LEDs
2 resistors

Quick test

Only one LED should be on at a time.
The pattern should repeat forever.

FILE: sketch.ino

sketch.ino

// C++ code
//
void setup()
{
  pinMode(13, OUTPUT);
  pinMode(9, OUTPUT);
}

void loop()
{
  // your led will glow/on
  digitalWrite(13, HIGH);
  // your led glow for 500 miliseconds / half seconds
  delay(500); // Wait for 500 millisecond(s)
  digitalWrite(13, LOW);
  delay(500); // Wait for 500 millisecond(s)
  digitalWrite(9, HIGH);
  delay(500); // Wait for 500 millisecond(s)
  digitalWrite(9, LOW);
  delay(500); // Wait for 500 millisecond(s)
}

Tinkercad

Light-Controlled Motor Prototype

This prototype is useful for talking about thresholds and transistor-driven outputs.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Build the photoresistor voltage divider to A0.
Use a transistor for the motor output on pin 9.
Paste the sketch and adjust the threshold if needed.
Cover the photoresistor to test the dark condition.

Parts

Arduino Uno
Photoresistor and fixed resistor
DC motor with transistor driver
External motor supply if needed

Quick test

In bright light the motor should stay off.
In darker light the motor should switch on.

FILE: sketch.ino

sketch.ino

// C++ code

void setup()
{
  pinMode(7, OUTPUT);   // LED přímo na Arduinu
  pinMode(8, OUTPUT);   // ovládání tranzistoru
  pinMode(4, INPUT);    // tlačítko (pull-down)
}

void loop()
{
  int inputValue = digitalRead(4);

  if (inputValue == HIGH) {
    digitalWrite(7, HIGH);   // zapni 1. LED
    digitalWrite(8, HIGH);   // sepni tranzistor => 2. motor jede
  } else {
    digitalWrite(7, LOW);    // zhasni 1.led
    digitalWrite(8, LOW);    // vypni tranzistor => 2. motor jede
  }
}

Tinkercad

Motor Encoder Speed Reader

This one is a bit more advanced. It is still practical if you keep the reading time fixed.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Connect the encoder output to pin 2 so you can use an interrupt.
Paste the sketch and open the Serial Monitor.
Run the motor and read the pulse count each second.

Parts

Arduino Uno
Motor with encoder output
Wires for signal and power

Quick test

The Serial Monitor should print pulse counts again and again.
If the motor stops, the count should drop close to zero.

FILE: sketch.ino

sketch.ino

const int encoderPinA = 2;
const int encoderPinB = 3;

volatile long encoderCount = 0;

unsigned long lastTime = 0;
const int interval = 100; // ms (měřící okno)

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

  pinMode(encoderPinA, INPUT_PULLUP);
  pinMode(encoderPinB, INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(encoderPinA), updateEncoder, RISING);

  Serial.println("Mereni rychlosti...");
}

void loop() {

  if (millis() - lastTime >= interval) {

    noInterrupts();
    long pulses = encoderCount;
    encoderCount = 0;   // vynulování pro další měření
    interrupts();

    // pulsy za sekundu
    float pulsesPerSecond = pulses * (1000.0 / interval);

    Serial.print("Pulsy/s: ");
    Serial.println(pulsesPerSecond);

    lastTime = millis();
  }
}

void updateEncoder() {
  if (digitalRead(encoderPinB) == HIGH) encoderCount++;
  else encoderCount--;
}

Tinkercad

Railway Crossing Simulation

This project is nice when you want one bigger combined simulation with lights and movement.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Use pin 2 for the train sensor or button.
Use pin 9 for the servo.
Use pins 5, 6, and 7 for the LEDs.
Paste the code and trigger the crossing event.

Parts

Arduino Uno
Servo motor for the gate
2 red LEDs
1 green LED
Button or sensor input

Quick test

When triggered, the gate should move down and the red LEDs should flash.
After the short wait, the gate should return up and the green LED should come back.

FILE: sketch.ino

sketch.ino

#include <Servo.h>

// Define constants for the components
const int buttonPin = 2;   // pushbutton pin
const int ledPin1L = 13;   // 1st Indicator LED Left pin
const int ledPin1R = 12;   // 1st Indicator LED Right pin
const int ledPin2L = 11;   // 2nd Indicator LED Left pin
const int ledPin2R = 10;   // 2nd Indicator LED Right pin
const int whiteLed1 = 4;   // White LED 1
const int whiteLed2 = 3;   // White LED 2
const int servo1Pin = 7;   // 1st Crossing Guard Servo pin
const int servo2Pin = 6;   // 2nd Crossing Guard Servo pin
const int buzzerPin = 5;   // buzzer pin (optional)

// Variables
int buttonState = LOW;     
bool sequenceRunning = false;  

// Timing variables for slow blinking
unsigned long previousMillis = 0;
const long blinkInterval = 700;  // slow blink every 700 ms
bool whiteLedState = false;

// Create servo objects
Servo myServo1;
Servo myServo2;

void setup() {
    pinMode(buttonPin, INPUT);

    pinMode(ledPin1L, OUTPUT);
    pinMode(ledPin1R, OUTPUT);
    pinMode(ledPin2L, OUTPUT);
    pinMode(ledPin2R, OUTPUT);

    pinMode(whiteLed1, OUTPUT);
    pinMode(whiteLed2, OUTPUT);

    myServo1.attach(servo1Pin);
    myServo2.attach(servo2Pin);

    CrossingGuardsUp();

    pinMode(buzzerPin, OUTPUT);

    Serial.begin(9600);
    Serial.println("Train Crossing Active!");
}

void CrossingGuardsDown() {
    myServo1.write(180);
    myServo2.write(0);
}

void CrossingGuardsUp() {
    myServo1.write(90);
    myServo2.write(80);
}

void FlashLEDs(int flashTimes, int flashDelay, bool beep) {
    for (int ctr1 = 0; ctr1 < flashTimes; ctr1++) {
        digitalWrite(ledPin1L, HIGH);
        digitalWrite(ledPin2R, HIGH);
        digitalWrite(ledPin2L, LOW);
        digitalWrite(ledPin1R, LOW);

        if (beep) digitalWrite(buzzerPin, HIGH);
        delay(flashDelay);
        if (beep) digitalWrite(buzzerPin, LOW);

        digitalWrite(ledPin2L, HIGH);
        digitalWrite(ledPin1R, HIGH);
        digitalWrite(ledPin1L, LOW);
        digitalWrite(ledPin2R, LOW);
        delay(flashDelay);
    }

    digitalWrite(ledPin1L, LOW);
    digitalWrite(ledPin2R, LOW);
    digitalWrite(ledPin2L, LOW);
    digitalWrite(ledPin1R, LOW);
}

void blinkWhiteLEDs() {
    // Only blink when the sequence is NOT running
    if (sequenceRunning) return;

    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= blinkInterval) {
        previousMillis = currentMillis;

        whiteLedState = !whiteLedState; // toggle state

        digitalWrite(whiteLed1, whiteLedState);
        digitalWrite(whiteLed2, whiteLedState);
    }
}

void loop() {
    // Always handle white LED blinking
    blinkWhiteLEDs();

    buttonState = digitalRead(buttonPin);

    if (buttonState == HIGH && !sequenceRunning) {
        sequenceRunning = true;  
        Serial.println("Train Crossing Button Pressed!");

        // Turn OFF white LEDs during sequence
        digitalWrite(whiteLed1, LOW);
        digitalWrite(whiteLed2, LOW);

        FlashLEDs(7, 200, true);

        CrossingGuardsDown();

        FlashLEDs(20, 200, true);

        CrossingGuardsUp();

        FlashLEDs(5, 200, false);

        // Restart slow blink
        previousMillis = millis();
        whiteLedState = false;
        digitalWrite(whiteLed1, LOW);
        digitalWrite(whiteLed2, LOW);

        sequenceRunning = false;
    }
}

Tinkercad

Motion Sensor with Servo Gate

Use a PIR sensor to open a servo gate, keep it open while motion continues, then warn with an LED before the gate closes again.

Track: TinkercadPIR input + warning LED + servo gate

Wire steps

Connect the PIR signal pin to digital pin 7.
Connect the warning LED to pin 3 through a resistor.
Connect the servo signal wire to pin 9 and power it correctly.
Paste the sketch into Tinkercad Code or Sketch.ino and start the simulation.

Parts

Arduino Uno
PIR sensor
Servo motor
LED
220 ohm resistor

Quick test

When motion is detected, the servo should open to 90 degrees.
If motion continues, the open timer should reset.
Before closing, the LED should turn on and blink as a short warning.
After the delay, the servo should return to 0 degrees.

FILE: sketch.ino

sketch.ino

#include <Servo.h>
 
Servo myServo;
const int pirPin = 7;    // PIR Signal pin
const int ledPin = 3;   // LED Pin
const int servoPin = 9;  // Servo PWM pin
 
int pirState = LOW;      
int val = 0;            
unsigned long motionDetectedTime = 0;
unsigned long timeToClose = 5000; // Time in ms to stay open (5s)
unsigned long warningTime = 3000; // Warning duration (2s)
bool servoOpen = false;
 
void setup() {
  pinMode(pirPin, INPUT);
  pinMode(ledPin, OUTPUT);
  myServo.attach(servoPin);
  myServo.write(0); // Start closed
  Serial.begin(9600);
}
 
void loop() {
  val = digitalRead(pirPin);
 
  if (val == HIGH) { // Motion detected
    digitalWrite(ledPin, LOW); // Turn off warning if motion re-detected
    myServo.write(90); // Open
    if (!servoOpen) {
      Serial.println("Motion detected - Opening");
      servoOpen = true;
    }
    motionDetectedTime = millis(); // Reset timer
  } else {
    // No motion detected, check if we need to start warning
    if (servoOpen && (millis() - motionDetectedTime > (timeToClose - warningTime))) {
      // 2 seconds before closing
      digitalWrite(ledPin, HIGH); // Turn on warning LED
     
      // Close the servo after the warning
      if (millis() - motionDetectedTime > timeToClose) {
        digitalWrite(ledPin, LOW);
        delay(50);
        digitalWrite(ledPin, HIGH);
        delay(50);
        digitalWrite(ledPin, LOW);
        delay(50);
         digitalWrite(ledPin, LOW);
        delay(50);
        digitalWrite(ledPin, HIGH);
        delay(50);
        digitalWrite(ledPin, LOW);
        delay(50);
        digitalWrite(ledPin, LOW);
        delay(50);
        digitalWrite(ledPin, HIGH);
        delay(50);
        digitalWrite(ledPin, LOW);
        delay(2000);
         myServo.write(0); // Close
        Serial.println("Closing");
        servoOpen = false;
      }
    }
  }
}

Tinkercad

Temperature Indicator with LEDs

This build is useful when you need one sensor task with thresholds and visible output.

Track: TinkercadUse the screenshot and sketch together

Wire steps

Wire the temperature sensor output to A0.
Wire the LEDs to pins 8, 9, and 10.
Paste the sketch and start the simulation.
Change the temperature in Tinkercad and watch the LED state change.

Parts

Arduino Uno
TMP36 or similar analog temperature sensor
3 LEDs
3 resistors

Quick test

Low temperature should light the cold LED.
Middle temperature should light the normal LED.
High temperature should light the hot LED.

FILE: sketch.ino

sketch.ino

int baselineTemp = 0;
int celsius = 0;
int fahrenheit = 0;

void setup()
{
  pinMode(A0, INPUT);
  Serial.begin(9600);

  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop()
{
  baselineTemp = 40;
 
  celsius = map(((analogRead(A0) - 20) * 3.04), 0, 1023, -40, 125);
 
   fahrenheit = ((celsius * 9) / 5 + 32);
  Serial.print(celsius);
  Serial.print(" C, ");
  Serial.print(fahrenheit);
  Serial.println(" F");
 
   if (celsius < baselineTemp) {
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
  }
  if (celsius >= baselineTemp && celsius < baselineTemp + 10) {
    digitalWrite(2, HIGH);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
  }
  if (celsius >= baselineTemp + 10 && celsius < baselineTemp + 20) {
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, LOW);
  }
  if (celsius >= baselineTemp + 20 && celsius < baselineTemp + 30) {
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, HIGH);
  }
  if (celsius >= baselineTemp + 30) {
    digitalWrite(2, HIGH);
    digitalWrite(3, HIGH);
    digitalWrite(4, HIGH);
  }
  delay(1000);
}

Tinkercad and Arduino projects

Main idea

How to use the Tinkercad builds

Use the picture first

Name the pins

Test one thing

LED Dice

Wire steps

Parts

Quick test

LED Sequence Prototype

Wire steps

Parts

Quick test

Motion Alarm with Buzzer and Servo

Wire steps

Parts

Quick test

Running Lights with Potentiometer Control

Wire steps

Parts

Quick test

Motion Alarm with LEDs

Wire steps

Parts

Quick test

Two Blinking LEDs

Wire steps

Parts

Quick test

Light-Controlled Motor Prototype

Wire steps

Parts

Quick test

Motor Encoder Speed Reader

Wire steps

Parts

Quick test

Railway Crossing Simulation

Wire steps

Parts

Quick test

Motion Sensor with Servo Gate

Wire steps

Parts

Quick test

Temperature Indicator with LEDs

Wire steps

Parts

Quick test