In embedded system product development there are quite number of tools and framework for unit testing the C code. In this blog post I will explain about how to mock local variable in ceedling for unit testing. Ceedling is one of the widely used open source framework for your test driven product development (TDD) in embedded systems. What is Ceedling 'Ceedling' is open source framework used in unit testing, in our project which involves embedded system development we are using 'ceedling' framework. Ceedling works together with Unity and CMock. Both are are open source tools for testing C code. Ceedling has feature of automatic generation of mock. Read more about ceedling features in our previous blog post. Unit Testing Tools Unit