How To Test Your IoT Product Before Launch

IoT device designers and manufacturers face incredible pressure to launch devices while avoiding unnecessary cost, time, or complexity. Because embedded teams are often constrained by time and budget limitations, testing before product launch is even more critical for IoT companies. Inadequate testing can result in severe consequences, including reputation damage or product failure. Rigorous test coverage is vital as it ensures device reliability and performance and can help reduce the risk of bricked devices caused by faulty firmware updates. For device makers, comprehensive testing provides the crucial balance between swiftly getting a product to market and ensuring its quality and reliability. In this blog, we’ll discuss some basics of testing to help you get started today.

Defining Your Testing Objectives

Clearly defined testing goals provide a roadmap for your software testing efforts, ensuring that you focus on the most critical aspects of the project. To identify specific objectives for your product, follow these steps:

1. Understand the business context, including goals, constraints, and risks, to help align your metrics with larger business goals. 
2. Set SMART objectives - Specific, Measurable, Achievable, Relevant, and Time-bound goals to improve quality.
3. Choose the appropriate testing approach and techniques that best suit your project while considering available resources and critical development areas.
4. Consistently evaluate and improve the testing process through retrospectives for tighter alignment between evolving business needs and a more effective software testing strategy.

Building a Comprehensive Test Plan

A comprehensive test plan will involve critical testing components, a general template that can be followed, and several testing phases. 

Components of a robust test plan should:

• Cover individual software components, like filesystems, BLE and Wi-Fi stacks, data structures, and complex algorithms. 
• Outline procedures for stubbing, faking, and mocking low-level embedded software implementations. 
• Emphasize Test Driven Development (TDD) practices to ensure unit tests cover most code paths, argument bounds, and failure cases—ultimately leading to increased stability, reduced debugging time, and prevention of issues like deadlocks, HardFaults, and memory leaks.

Building a skilled and diverse testing team will bring various perspectives and insights, helping identify potential issues from multiple angles. Teams should leverage a template or framework for creating a test plan in embedded projects that should start with a clear understanding of the project's context, including goals, constraints, and risks. Considerations should include:

• Which testing approaches and techniques should be used (such as unit testing using frameworks like CppUTest 3.8).
• An outline for documenting, communicating, and revising the testing plan as the project evolves, ensuring consistency and transparency in testing activities.
• A plan for various testing phases to uncover issues early in the development cycle, prevent regressions, and maintain a well-structured and robust codebase.

Types of Testing (or Testing Phases)

Unit testing, integration testing, system testing, and end-to-end testing all work to verify the interactions between different components, ensure the overall system's functionality and reliability, and validate the software's behavior in real-world scenarios. 

Unit testing can be beneficial and easy after a brief introduction and a few test runs of writing your own tests. Projects that benefit from unit testing are those that require filesystems, BLE and Wi-Fi stacks, specialized data structures (both in-memory and in-flash), and complex algorithms like those interpreting gyroscope and accelerometer data. 

Integration testing is always conducted after unit testing when developers gradually integrate several components and test the interfacing between the inter-connected components as a combined entity to ensure that the different modules work correctly in the overall system. Integration testing is crucial to stay in compliance and eliminate issues not found during unit testing.  

System testing is then performed after integration testing to check the system as one for both functional and non-functional testing (usability, reliability, performance, etc). System testing helps identify system defects and ensures the system meets any specified requirements.

End-to-end (E2E) testing involves testing the entire process of using software from an end-user’s perspective, from the beginning to the end of the end-user experience. If your end product is a set of API endpoints, then your E2E tests should use the API endpoints directly with the standard authentication methods that your app expects.

Best Practices for Getting Started with the Right Testing Tools

Choosing the right testing tools is key. In complex and interdependent firmware code, best practices for unit testing involve breaking down tests into discrete paths or features within a module. To get started, here are a few basic best practices and tools:

1. Each test should execute quickly, ideally in just a few milliseconds, ensuring efficient testing. Unit tests should ideally include one real module implementation, with the rest being stubbed or fake versions of modules not under test. These stubs and fakes should be created early, reused, and shared to simplify testing. Stubs, fakes, and mocks are essential in this context, allowing developers to isolate specific module behaviors and interactions during testing.
   • Stubs serve as minimal implementations when specific functions' implementation or return values are irrelevant for testing. They are beneficial for fixing linker errors and should generally include only return statements, such as true, false, 0, or NULL, based on the context of the module.

• • Fakes are practical in situations where using the real implementation is impractical, such as when it relies on specific hardware. For example, a fake mutex module can check that all mutexes were correctly unlocked after testing.

• • Mocks are powerful tools that allow developers to specify each return value of a function, providing granular control over testing scenarios. They are particularly useful for testing every code path of the module under test by forcing functions to return specific error codes, NULL values, or invalid pointers.

Analyzing Test Results

Interpreting test results accurately is the cornerstone of a successful analysis. Examine test results meticulously, comparing actual outcomes with expected ones and recognizing recurring patterns or issues.

Swift issue identification and resolution are crucial for preventing escalations, cost-efficiency, and user satisfaction. Tailor your incident response to test outcomes based on the severity and nature of the issues:

• Minor Issues: For minor issues that don't affect functionality, consider addressing them in a post-launch OTA update.
• Critical Bugs: Critical issues that impact core functionality should be addressed immediately and may necessitate a delayed launch or a hotfix.
• Performance Optimization: If performance issues are identified, develop a plan to optimize the product's performance through updates.
• User Feedback: User feedback can provide valuable insights. Develop an action plan to address common user concerns and continually improve the product.

Why You Should Adopt an Iterative Approach 

Iterative testing is integral for continual product enhancement. By consistently collecting and analyzing data from embedded systems, developers can swiftly detect issues, optimize performance, and rectify software bugs in real-time. Using it enables embedded software and firmware to evolve and excel over time.

Elements of an iterative approach include:

• Prioritizing effective feedback loops as part of product development strategy. These loops facilitate the collection of invaluable insights from devices in the field, enabling companies to receive real-world feedback directly from users. 
• Actively soliciting customer input and integrating it into the development process.
• Embracing the principle of continuous improvement. Getting to launch used to be the whole ball game; now, it’s as important as ever to ensure that released products are reliable, secure, and regularly delivering value to end users. 

By building products with an iterative approach, teams can deploy ongoing monitoring, testing, and analysis of device performance and software behavior and refine and innovate even after a product has been launched. 

User Testing and Feedback

Beyond customers, an iterative approach requires engaging friendly, non-technical customers (friends, family, and co-workers) in beta testing to obtain diverse perspectives. To gather user feedback effectively, companies should consider:

• Building an in-app bug reporting system within IoT device applications to streamline communication between customers and developers, promoting real-time feedback collection and improving product stability. 
• Integrating data-retrieval methods that do not require user input, like a system that enables you to capture bug data automatically without user reports.
• Capturing device metrics, including battery life, CPU usage, and connectivity for thorough monitoring and analysis, aiding customer support and engineering teams in issue diagnosis and data-driven decision-making for future product enhancements. Memfault makes it easy to select custom metrics.

The days leading up to your product launch are critical. Before your IoT product goes live, ensure you've conducted all the tests listed above. Maintain a checklist that covers software updates and documentation, and ensure your customer support team is prepared. The final sign-off process is a pivotal step to declare product readiness. Prioritize comprehensive testing to secure a successful product launch.

For a real-world example of how a reliable testing solution can lead to a successful product launch, read more about Memfault’s customer, Diamond Kinetics, a leading sports technology provider. Diamond Kinetic’s experience showcases the power of strategic testing and the role of trusted partners in accelerating development and confidently bringing an IoT product to market.