Aim:
To debug a non-working Arduino project in Tinkercad by finding and correcting errors in wiring and code.

Requirements:

• Computer with Internet

• Tinkercad Circuits

• Arduino Uno, LED, Resistor, Sensors (as per circuit)

• A faulty preloaded circuit (teacher can prepare this in advance with errors)

Steps:

Step 1: Open the faulty circuit

• In Tinkercad, load the “Broken Circuit” shared by your teacher.

• The project might look fine, but it won’t work when you run it.

Step 2: Run the simulation

• Click Start Simulation.

• Observe carefully:

  • Does the LED light up?

  • Does the Serial Monitor print correct values?

  • Does the fan or buzzer respond to sensor input?

Step 3: Check the wiring

• Trace each wire from sensor/device → Arduino pin.

• Common wiring errors to look for:

  • Connected to the wrong pin (e.g., LED connected to pin 10 but code says pin 9).

  • Ground (GND) missing.

  • Resistor missing → LED burns too bright or doesn’t work.

  • Power not connected to VCC/5V.

Step 4: Check the code

• Open the Code editor in Tinkercad.

• Look for mistakes such as:

  • Wrong pin number in digitalWrite() or analogRead().

  • Missing semicolon ; at the end of a line.

  • Using = instead of == in an if condition.

  • Logic mistakes (threshold too high/low, so output never turns ON).

Example of faulty code:

int led = 9;

void setup() {

  pinMode(led, OUTPUT)

}

void loop() {

  digitalWrite(10, HIGH);

}

👉 Errors:

1. Missing semicolon after pinMode.

2. LED connected to pin 9, but code uses pin 10.

Corrected version:

int led = 9;

void setup() {

  pinMode(led, OUTPUT);

}

void loop() {

  digitalWrite(led, HIGH);

}

Step 5: Correct and test again

• Fix the wiring and code.

• Run simulation once more.

If it still doesn’t work → repeat the process until it works.