Testing/Validation

Unit Testing Frameworks

Supported Testing Libraries

STM32CubeIDE projects can leverage several unit testing libraries tailored for embedded systems development. Commonly used frameworks include:

  • Unity: A lightweight and easy-to-use C unit testing framework designed for embedded environments.

  • Ceedling: A build system and test runner built on top of Unity, providing automation and test management features.

  • CppUTest: A C/C++ testing framework suitable for embedded systems with support for mocks and test doubles.

  • Google Test: While more common in desktop environments, it can be adapted for embedded testing with cross-compilation.

These libraries facilitate writing and running unit tests to validate individual modules and functions in isolation.

Writing and Running Unit Tests

To write effective unit tests:

  • Organize tests by module or functionality.

  • Use assertions provided by the testing framework to verify expected behavior.

  • Mock hardware dependencies to isolate logic under test.

  • Automate test execution using build scripts or test runners like Ceedling.

Running unit tests can be done:

  • Directly on the host machine using cross-compiled test binaries.

  • On the target hardware via debug probes or serial output.

  • Integrated into continuous integration pipelines for automated validation.

Integration and System Testing

Automated Test Execution

Automated test execution streamlines validation by running test suites without manual intervention. In VS Code, this can be configured using tasks or external scripts triggered after builds.

Key practices include:

  • Scheduling tests to run on code commits or nightly builds.

  • Collecting and reporting test results in standardized formats.

  • Integrating with continuous integration (CI) tools for end-to-end automation.

Test Coverage Analysis

Test coverage tools measure the extent to which your codebase is exercised by tests, identifying untested areas.

For STM32CubeIDE projects:

  • Use GCC’s –coverage flags ( -fprofile-arcs -ftest-coverage ) to instrument code.

  • Generate coverage reports with tools like gcov and lcov .

  • Analyze reports to improve test completeness and quality.

Hardware-in-the-Loop (HIL) Testing

Setting up HIL Environments

Hardware-in-the-Loop testing involves running your embedded software on real hardware connected to simulated environments that mimic real-world inputs and conditions.

To set up HIL testing:

  • Connect the STM32 target to simulation hardware or software simulators.

  • Configure interfaces such as UART, CAN, or GPIO for test signal exchange.

  • Develop test scenarios that stimulate hardware inputs and verify outputs.

  • Use tools like MATLAB/Simulink or dedicated HIL platforms for simulation control.

Debugging Test Failures

Debugging failures in testing requires systematic analysis:

  • Review test logs and output messages for error indications.

  • Use debug probes and breakpoints to step through failing code sections.

  • Verify hardware connections and signal integrity in HIL setups.

  • Isolate failures by running smaller test cases or unit tests.

  • Collaborate with hardware and software teams to resolve integration issues.