Building Tests

Frequently when developing device firmware, small test programs need to be made to ensure correct operation. These small programs may be useful for troubleshooting in the future or as examples on how to use certain components.


  • Only a single test should be compiled into the final image.
  • Tests should be selected out-of-tree (Using CMake options)
  • The image should always compile no matter what is configured


The operation relies on two cmake options, one boolean and one string. The first option, EMA_BUILD_TESTS controls whether tests are compiled at all. If set to ON, the TEST define will be included in your code. The second option, EMA_TEST, controls which test is actually used. See below on details on how to set EMA_TEST.

Making new tests

To make a new test, open the file “test/test.c”. Within this file is a large #ifdef/#elif structure. Just add a new #elif section in here and name the define similarly to the others. Keep the name you chose in mind, as this name is what you must set EMA_TEST to in order to use the new test.

Running Tests

NOTE: If you don’t have access to the cloud, the values will not print when running tests. You will have to place checkpoints in your test code and use the VS Code debugger to see values. Ensure you do not place too many checkpoints as this might prevent the code from building.

After setting up the firmware toolchain as per Device Firmware, you should have a working visual studio setup. From the command palette (Ctrl+Shift+p), select “Cmake: Edit Cmake Cache (ui)”. From here you can search for EMA_BUILD_TESTS and EMA_TEST in order to set them. When finished, press the button labeled “SAVE”.