Just like application software can benefit from TDD, embedded projects or projects that involve hardware interactions can also benefit from the TDD approach. Interestingly, embedded projects or products that involve hardware benefit more from TDD as they can test most part of their code without the hardware by isolating the hardware dependency. TDD helps reduce time to market as most part of the software can be tested by the team without waiting for the hardware. As most part of the code is already tested thoroughly without hardware, it helps avoid last-minute surprises or firefighting when the board bring-up happens. This is because most of the scenarios would have been tested thoroughly.

As per software engineering best practices, a good design is loosely coupled and strongly cohesive in nature. Though we all strive to write code that is loosely coupled, it isn't possible to write code that is absolutely independent all the time. Most times, the code has some type of dependency. In the case of application software, the dependency could be a database or a web server; in the case of embedded products, the dependency could be a piece of hardware. But using dependency inversion, code under test (CUT) can be isolated from its dependency, enabling us to test the code without its dependency, which is a powerful technique. So as long as we are open to refactoring the code to make it more modular and atomic, any type of code and project or product will benefit from the TDD approach.