| GPIO 2-Pin Test |
| ############### |
| |
| This application tests the GPIO subsystem using a hardware configuration |
| where two GPIOs are directly wired together. The test pins are |
| identified through a test-specific devicetree binding in the `dts/` |
| subdirectory, implemented for specific boards by overlay files in the |
| `boards/` directory. |
| |
| For some boards `src/main.c` may also need to be extended to configure |
| the selected pins for use as GPIOs. |
| |
| Only boards for which an overlay is present can pass this test. Boards |
| without an overlay, or for which the required wiring is not provided, |
| will fail with an error like this: |
| |
| Validate device GPIO_0 |
| Check GPIO_0 output 2 connected to input 3 |
| FATAL output pin not wired to input pin? (out high => in low) |
| |
| No special build options are required to make use of the overlay. |
