Test arduino sketch

How to Run/test Your Arduino Code Online for Free?

Introduction: How to Run/test Your Arduino Code Online for Free?

There are various options to run Arduino code online. Which is the best depends on how useful it is to the user’s specific use case. there can not be one scale to measure the performance of all such Arduino simulation options. Some are free, some are paid, some are up to date and some are outdated, some have good options and some have poor. So, I cannot quantise. Let us start with my preferred approach, Wokwi Arduino Simulator 👉👉

Step 1: No Installations No Downloads! — Open a Browser

Open any browser. Currently, all the browsers support the Arduino simulation code execution.

In this tutorial, I will use either firefox or Avast secure browser. I have not seen any significant differences in the performance of the Arduino simulator.

Before we start,

  1. The Arduino code running online or on a simulator may not guarantee the same performance of behaviour when it comes to real hardware
  2. The real hardware poses you more challenges (open connections, short connections, missing connections, pullups, noise, floating pins, dry solder, poor solder, incompatible voltage, insufficient setup and hold times, ringing etc
  3. Software simulations are just the steps to learn but it is not the final destination

A request:

Please comment and like this project, if you find this helpful. Also, feel free to ask questions or suggest any new topics. I will be glad to reply and improve 😀

LED blink code is the basic example which most of us would have run when exploring hardware circuitry involving an MCU. This is definitely equivalent to the «Hello World» program in computer languages 😀. In this step, we will see how we can test our basic LED blinking code for Arduino

To verify the LED code online, please visit

The view is something like the image shown (might be slightly outdated) 😅

the Right pane is where we will put the code :)

Let us try a few LED blink examples:

once I copy the code and paste it in the link above, I could run and test my Arduino code online 😀

Please let me know if you have any trouble in running the LED code in the Link above. Next, we will see the servo motor code.

Step 3: How to Test Your Arduino Servo Motor Code Online?

Servo Motors are intelligent motors which can understand the angle of rotation based on the PWM width we drive with. They have built-in comparators which compared the width of the PWM and then act accordingly. They are used in robotics, pick and place and many such examples. These are definitely of interest to hobbyists. In this step, we can see how one can play with Arduino Servo motor simulations as well as test their own code online for free 😃

  • Copy the servo motor code you want to test. Let me also take a random code from the internet

This is the code from

Here is the code from Arduino Stackexchange- just random:

  • The copied code is pasted into the editor field of the shared link
  • The RUN code button was pressed.
    • Note that it will take some time to compile one time (in a few seconds). If you stop and rerun it will be instant.
  • Play with the simulations as long as you want.
  • Here is the screenshot of the Arduino Servo motor code in action :)

Please leave a comment if you have any questions.😀

Step 4: How to Test Arduino NeoPixel LEDs Online?

NeoPixel LEDs are individually addressable LEDs. Only one data line is connected to all the LEDs. All the LEDs in the strip are connected in series. Each LED will have a small logic IC which will understand the incoming data, process it and light up the RGB LEDs accordingly. It is quite a fascinating idea which is now a globally called FastLEDs or NeoPixel LEDs, but basically, all these are individually addressable LEDs.

Please leave a comment if you have any questions

It is possible to change the number of LEDs to 24 or any number you want

It is possible to also change the Arduino pin number to which the LED data line is connected to

Please leave a comment if you have any questions

In the coming days, there will be an updated user interface where it will be even more fun to play with the simulations 🙂

Let us see how to test your LCD code online in the next steps

Step 5: How to Test Your SSD1306 OLED Arduino Code Display

The OLEDs are great. They lit really well. They don’t consume any power when the display is minimal. They can be read in an outdoor environment as well. They make a great HMI value addition for any projects. We can display text, number, graphics and stories on it. It is indeed a good tool and skill to have it. Let us ee how to get the OLED Arduino code online here 👇

  • Visit https://wokwi.com/playground/ssd1306
  • Copy your code and paste it into the editor field
  • It is usual to have the I2C address of the SSD1306 OLED to have either 0x3D or 0x3C as the address.

I have used the existing code directly present in the link, but I hope it is straight forward to replace the code in the editor contents to swap with the code you want to test

Please ask questions if you have any. Please comment and like if this is useful 😃

In the next step, I will share how I test the LCD1602 Arduino code online 👉

Step 6: How to Test Arduino LCD1602 Code Online?

LCD1602 when I say, I mean LCD display with 16 columns and two rows. It usually comes with a backlight. the background will either be green or blue for most of the cases. The display is there for decades and is still a good low-cost HMI to add to the projects. Advantage of the readability of the display without backlight in sunlight should not be forgotten 👌

  • Visit https://wokwi.com/playground/lcd1602-i2c
  • Delete the prefilled code in the editor window
  • Paste the example code in the editor window
  • There are a few things to take care
    • Contrast settings
    • Backlight
    • data connections can be 4 bit or 8 bit. 4 bit is sufficient enough as we don’t have to spend a huge amount fo data
    • I2C connections are also a possibility. As of now, this is for LCD in which I2C lines are connected

Let me choose a random LCD1602 code from the internet for example:

Please leave comments 🙏 if you have any questions or suggestions

Step 7: Going Forward 👨‍🏫👩‍💻👨‍🚀

  • You might not be able to run the code for a few use cases, but don’t worry, this link, for example, shows how much useful the Wokwi Simulator is for you https://wokwi.com/arduino/libraries
  • If you want to change the UNO to nano or Mega it is possible as well
  • You can define your own connections, position the peripherals in the way you want and much more
  • Please subscribe here: https://wokwi.com/arduino/libraries/Adafruit_NeoP.

other links which might interest you:

We’ve always defined ourselves by the ability to overcome the impossible. And we count these moments. These moments when we dare to aim higher, to break barriers, to reach for the stars, to make the unknown known. We count these moments as our proudest achievements. But we lost all that. Or perhaps we’ve just forgotten that we are still pioneers. And we’ve barely begun. And that our greatest accomplishments cannot be behind us, because our destiny lies above us.

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Скетч для проверки работоспособности портов и EEPROM

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Написал универсальный скетч для проверки работоспособности портов и EEPROM памяти. Ищутся добровольцы для проверки в железе и доработки тестовой программы. Мой код проверен на ATmega128A, ATmega8A при этом никаких правок в коде делать не нужно. Количество цифровых и аналоговых выводов определяется автоматически.

Что еще нужно сделать:

1. Проверка аппаратных прерываний, таймеров, прерываний по переполнению таймера.

2. Прошивка на асме для проверки RAM, Stack Pointer Register, Status Register, регистров R0-R25, X,Y,Z

Что уже было сделано: Мой код при запуске ничего не делает, он ждет команду по UART. В терминал нужно отправить одну английскую букву для запуска нужного теста. Когда какой то тест был запушен, ч тобы его прервать нажмите кнопку ресет. Список комманд :

v — Выводит версию программы и краткое описание доступных тестов.

a — АЦП тест . Выводит значения всех аналоговых входов. Для этого вы подключаете переменный резистор поочередно к каждому аналоговому входу и смотрите как меняются значения.
i — Inputs test . В этом тесте включена подтяжка всех входов (INPUT_PULLUP). Тест в ыводит значения всех входов с низким уровнем на них. Вы берете провод подключенный на землю и через резистор 1КОм по очереди качаетесь каждого входа, в терминале должна появиться только одна надпись LOW с номером вывода. Этот тест позволяет найти замкнутые между собой пины или дорожки с обрывом (а также выводы со сгоревшими внутренними PULLUP резисторами )
o — Outputs test . Устанавливает все порты как выход с 1 на них. Вы берете тестер или светодиод с резистором и проверяете наличие высокого уровня на каждом выходе.
b — Blink . Тест наплатного светодиода.
0 — ZEROFILL встроенного EEPROM (тоесть заполнение нулями 0x00 во все ячейки ). Тест закончится, когда будет выведено «Done» в консоль. После этого запустите комманду » e » для вывода содержимого EEPROM в консоль и проверьте нет ли бытых ячеек
1 — 0xFF заполнение встроенного EEPROM. Тест закончится, когда будет выведено «Done» в консоль. После этого запустите комманду » e » для вывода содержимого EEPROM в консоль и проверьте нет ли бытых ячеек
p — Тест ШИМ на наплатном светодиод е . Тест надо полностью переписать, текущая реализация мне не нравится.

e — Выводит все содержимое EEPROM в терминал.

Цифровые порты 0 и 1 не тестируются. Этот тест предполагает, что выводы 0 ( RX ) и передачи данных 1 ( TX ) данных в порядке , раз у вас получилось загрузить скетч .

Код состоит из двух файлов. Последняя версия всегда доступна по ссылке


Test arduino sketch

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Test your Arduino projects with GitHub Actions

This article was written by Per Tillisch from the Arduino Tooling Team.

The Arduino team created some tools that make it easy to automate a check for whether your Arduino sketches compile. Used with GitHub Actions, the tools allow anyone to set up a simple “smoke test” on every commit and pull request made to a GitHub repository, with reports on the impacts of those changes.

These free, open source actions are now listed on the GitHub Marketplace.

Why do a compile test?

Although passing a “Does it compile?” check is not definitive proof of a working project, failure to compile is a sure sign of a non-working project! For this reason, it can provide a useful “smoke test”.

Even if you have more formal tests in place, a compilation check remains a valuable supplement, since it is able to catch incompatibilities with the Arduino build system that other tests will miss.

The biggest advantage of this approach is that, unlike other testing methods, it takes very little effort to set up and maintain. All that’s needed is to define a few basic parameters of the compilations, such as which Arduino boards to compile for and which library dependencies of the sketch need to be installed. After that, everything is automatic!

GitHub Actions

GitHub Actions is the preferred automation service for continuous integration in the Arduino firmware repositories. Let’s take a look at its fundamental concepts.

Workflows define the procedure that should run when a specific event occurs in the repository. For example, you might have a workflow that runs every time someone submits a pull request to your repository. Using GitHub Actions is only a matter of adding a workflow configuration file to your repository.

Actions are programs that do specific tasks. These programs are packaged in a manner that makes them easy to reuse in any GitHub Actions workflow. By using combinations of the many actions provided by the open source community, you can easily do complex things with simple, easy to maintain workflows.

Actions for Arduino projects

Several GitHub Actions actions are available for use with Arduino projects. One of these is arduino/compile-sketches. As you might have guessed from the name, this is a tool for compiling Arduino sketches.

A complete workflow to compile the sketches in a repository can be as minimal as this:

On every commit and pull request, this workflow searches the subfolders of the repository recursively for sketches and compiles them for the Arduino Uno. If compilation of any of the sketches has an error, the commit status will be set to failure.

Next, let’s take a look at a workflow that shows some of the other features of the arduino/compile-sketches action:

This is a workflow used to test the sketches that accompany a machine learning tutorial. There are a few differences from the previous workflow:

The tutorial’s sketches were written for the Arduino Nano 33 BLE board, so instead of compiling for the action’s default Arduino Uno board as in the previous workflow, the workflow was configured to compile for the Nano 33 BLE by specifying that board’s fully qualified board name (FQBN) identifier (arduino:mbed:nano33ble) via the action’s fqbn input.

These sketches require some libraries to be installed. The names of the libraries are specified via the action’s libraries input. This causes them to be installed from the Arduino Library Manager.

Not just for sketches

Just because we are compiling sketches, that doesn’t mean this action can only be used to test sketches. Compiling a sketch is also testing whether the libraries and boards platform used by that sketch will compile. Continuous integration in library and platform repositories is especially important to avoid breaking components other people rely upon. These projects often have multiple sketches that need to be compiled for multiple boards, making automation of the task even more beneficial. If you’re a library or platform developer, we strongly recommend spending a little time to set up a workflow.

This is the workflow used to test the ArduinoBLE library:

This library supports multiple architectures, so the compilations must be done for several boards. This is done by creating a job matrix. A copy of the compile-examples job runs for each of the boards listed under the jobs.compile-examples.strategy.matrix.fqbn[] key, avoiding the need to define a separate job for each board in the workflow.

Don’t let its ease of use for basic applications fool you into thinking it’s not suitable for advanced use cases. arduino/compile-sketches is a powerful general purpose tool for compiling Arduino sketches. The configuration options provide a lot of flexibility that will make it useful no matter what your requirements are. See the documentation for details: https://github.com/arduino/compile-sketches#readme

Compilation data reports

The arduino/compile-sketches action can be configured to report the change in memory usage and compiler warnings resulting from commits and pull requests. These will be displayed in the build log:

A companion action, arduino/report-size-deltas, comments on pull requests with a report of the resulting change in memory usage of the sketches that were compiled by the arduino/compile-sketches action:

The workflow for arduino/report-size-deltas is very simple, and doesn’t require any modifications to be used in your repository:

Give it a try!

Continuous integration can reduce the tedious task of manual testing. You probably wouldn’t enjoy compiling multiple sketches for multiple boards for every commit and every pull request, but these new actions are happy to do it for you.

These actions are especially useful for pull request triage. They provide an initial “smoke test” of the pull request without any effort from the repository maintainer. If the workflow job for the pull request fails or reports an undue increase in memory usage, the contributor of the pull request will often work to resolve the issues revealed by the CI system on their own initiative, reducing some of the effort required to review contributions.

We use these actions in the Arduino firmware repositories and are sure you’ll also find them useful for your projects.

Support and feedback

You can discuss or get assistance with setting up continuous integration for your Arduino projects on the Arduino Forum.

Feedback is welcome! Please submit feature requests or bug reports to the issue trackers:

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