Ceedling is a build automation tool for C projects. It is especially adept at building and executing unit test suites — even for tricky embedded systems. Ceedling provides three core functions: [1] It packages up several tools including the C unit test framework Unity, the mock generation tool CMock, and other complementary frameworks and libraries. [2] It simplifies configuration for C toolchains. [3] It automates the running and reporting of test suites as well as release builds. Ceedling projects start with a YAML configuration file. A variety of conventions simplify assembling suites of unit test functions and producing release builds.