win32Arduino

win32Arduino is a Windows/Linux implementation of arduino functions. It allows a developer to unit test an arduino library outside of the arduino platform.

The library allows to easily unit test an arduino library using your testing framework of choice. For instance, the unit tests of win32Arduino library are executed using the Google Test framework.

Status

Build:

Service	Build	Tests
AppVeyor
Travis CI

Statistics:

AppVeyor	Travic CI

Features

The main features of the library are:

• Implements many arduino functions.
• Support all functions that reads or writes values to pins.
• Advanced time handling mechanism. Supports realtime, incremental or custom millis() and micros() functions to simulate time.
• Call history and logging support. Calls to the Serial class are also forwarded to the output log file.
• Attach function callbacks to any native arduino function.
• Attach function callbacks to millis() or macros() functions for time based event programming.
• Supports interrupts functions: attachInterrupt(), cli(), noInterrupts(), interrupts() and SREG registry.

Limitations:

• Pins specific functionality is disabled. In other words, all pins are identical and shall considered supporting analog and digital values.
• AVR, POWER, SERIAL, SPI, I2C is not supported.
• PWM is not supported. Simulating PWM changes over time on each PWM pins is hard.
• Pin resolution functions (analogReadResolution() and analogWriteResolution()) is not implemented. Pins values is always stored using a resolution of 10 bits.
• Shift functions (shiftIn() and shiftOut()) are not implemented.
• The following functions are also empty shells: tone(), noTone() and pulseIn().

Usage

The following instructions show how to use the library.

Testing your own library

Arduino library source code must be added to a win32/linux project to be compiled and tested outside of the arduino environment.

The following instructions show how to test your own library with win32Arduino.

1) Verify library prerequisites

To be compatible with the files provided by win32Arduino, an arduino library must implement the Arduino IDE 1.5: Library specification.

Source files must be stored in src/ directory.

Unit tests are expected to be written using the Google Test framework. This guide assumes that you are already familiar with the googletest API.

Unit test files must be stored in test/ directory.

2) Copy CMake template files to your library project

The win32Arduino expect your arduino library project to be compatible with the CMake build system. CMake build system is used to generate a platform-specific (Windows or Linux) build environment.

win32Arduino provides template files that must be copied from /usage/template/ directory into the arduino library project.

In case of conflict (if the copied files already exist or if your library is already using CMake), you must merge the files manually.

3) Build library unit tests

To generate the Windows or Linux project files, open a command prompt, browse to your arduino library directory and enter the following commands:

mkdir build
cd build
cmake ..

To build the project, enter the following command (based on your platform):

1. On Windows, run cmake --build . --config Release.
2. On Linux, run make command.

Troubleshooting

The CMakeLists.txt file is expecting to find your test files in the test/ directory and your library source files in the src/ directory.

Note that CMakeLists.txt file does not automatically search for dependencies. If the tested arduino library depends on another, you must manually edit the CMakeLists.txt file and add the required lines to resolve all dependencies and have a successful build.

Source code example

The following section shows an example of using win32Arduino.

Assume a developer needs to test the following library function:

bool waitForButtonPress(uint8_t buttonPin, uint32_t timeout) {
  uint32_t start = millis();
  while( millis() - start < timeout )
  {
    //look for button state
    int buttonValue = digitalRead(buttonPin);
    if (buttonValue == LOW)
      return true;
  }
  //timeout
  return false;
}

Using Google Test framework, one can write the following unit test to validate the behavior of the waitForButtonPress() function:

void simulatePinLowISR() {
  testarduino::setPinDigitalValue(2, LOW);
}
TEST(TestButtonLibrary, testWaitForButtonPressTimeout) {
  testarduino::reset();
  IncrementalClockStrategy & clock = IncrementalClockStrategy::getInstance();
  clock.setMicrosecondsCounter(0);
  clock.setMicrosecondsResolution(100); //increase simulated clock by 0.1ms for every calls to micros()
  static const uint8_t buttonPin = 2;
  static const uint32_t MAX_WAIT_TIME = 5000; //ms
  testarduino::setPinDigitalValue(buttonPin, HIGH); //simulate pin pull-up resistor

  //assert that false is returned if button is not pressed
  uint32_t time1 = millis();
  bool result = waitForButtonPress(buttonPin, MAX_WAIT_TIME);
  uint32_t time2 = millis();
  uint32_t elapsed = time2 - time1;
  ASSERT_FALSE(result);
  ASSERT_EQ(MAX_WAIT_TIME, elapsed);

  //configure win32Arduino library to push a button in 2000 ms.
  static const uint32_t BUTTON_DELAY_TIME = 2000; //ms
  uint32_t buttonPressTime = millis() + BUTTON_DELAY_TIME;
  attachMillisecondsCallback(buttonPressTime, simulatePinLowISR); //in 2000 ms, the button pin will go LOW

  //run the function again...
  //assert that function is interrupted when a button is pressed
  time1 = millis();
  result = waitForButtonPress(buttonPin, MAX_WAIT_TIME);
  time2 = millis();
  elapsed = time2 - time1;
  ASSERT_TRUE(result);
  ASSERT_EQ(BUTTON_DELAY_TIME, elapsed);
}

Build / Install / Testing

Please refer to file INSTALL.md for details on how installing/building the application.

Platforms

win32Arduino has been tested with the following platform:

• Linux x86/x64
• Windows x86/x64

Versioning

We use Semantic Versioning 2.0.0 for versioning. For the versions available, see the tags on this repository.

Authors

• Antoine Beauchamp - Initial work - end2endzone

See also the list of contributors who participated in this project.

License

This project is licensed under the MIT License - see the LICENSE file for details