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Coding track
Debugging practice

Arduino debugging practice with real planted bugs

Short puzzles with one fault each, in the wiring or the code. Then the meter, scope and Serial habits that find bugs from evidence.

FreeIn your browser3 courses, 27 lessons, about 13 hours
Start freeThe board with no groundSee the course
Overview

How you will learn it

Debugging is a skill you get by doing it, and most beginners only meet bugs by accident. Fix the bug hands you the most common ones on purpose: a missing ground, a wrong pin, a stray semicolon, an off-by-one count.

Each puzzle is a few minutes. When they feel easy, Debug like an engineer adds the tools and C++ on a board shows how to find a bug from the evidence instead of guessing.

Outcomes

What you will learn

  • Spot the wiring faults that keep a circuit dark.
  • Find the code faults that make a sketch almost work.
  • Use Serial output as evidence, not decoration.
  • Work through a circuit with several bugs in a fixed order.
Your route

The courses and lessons to take

Every lesson opens in the editor right away, signed in or not, and the simulator checks each step.

  1. Step 1 路 8 lessons 路 1 h

    Fix the bug

    Short puzzles, a few minutes each.

    1. The board with no groundPin 13 is high, the LED and resistor are wired to the rail, and nothing lights. Find what the loop is missing.
    2. The output that is not an outputdigitalWrite says HIGH and the LED barely glows. The loop is fine. Find what setup() leaves out.
    3. The count that stops at nineA for loop that should print 1 to 10 prints 1 to 9 and says done. Find where ten went.
    4. The if that always runsThe LED should light only while the button is held, and it is on all the time. One character is to blame.
    Every lesson in the course
  2. Step 2 路 13 lessons 路 10 h

    C++ on a board

    A bug found from the evidence.

    1. A bug, found from the evidenceA score that goes down on the fifth press and a lamp that goes out when it should stay on. Find it from what the board prints, not from staring at the code.
    Every lesson in the course
  3. Step 3 路 6 lessons 路 2 h

    Debug like an engineer

    Serial like a pro, then one circuit with three bugs.

    1. Reading Serial like a proPrint debugging done well: labeled and timestamped lines, a warning word you can search for, and a verbose switch you flip from the Serial Monitor without rebuilding.
    2. Boss: one circuit, three bugsA button and an LED that do nothing, with three faults planted at once. Use the method engineers use (reproduce, isolate, measure, fix) and a meter to find all three.
    Every lesson in the course
Keep going

Guides and tools on the same subject

Track

Coding track

Python and C++ from your first print to classes, tests and state machines. Every program runs on a simulated board, so a bug is something you can see.

See the whole track
Questions

Questions people ask

What are the most common Arduino bugs?

A missing ground, a pin never set to OUTPUT, a button read without a pull-up, a loop that stops one short, and an if with a stray semicolon. Fix the bug has each of them.

How do I debug an Arduino without a debugger?

Print what the code believes with Serial, measure what the circuit is doing with a meter or scope, and compare the two. The lessons build that habit.

Is this good practice for interviews?

Yes. Explaining how you found a bug, step by step, is exactly what hardware and firmware interviews ask for.