Testing GPIO functionality

The functionality of the GPIO pins can be tested in different ways.

• Input mode test – Driving external signal and reading corresponding pin status from nRF9160 registers.
• Output mode test – Setting pin high or low from nRF9160 and measuring signal level with external test equipment.
• Input leakage test – Disconnecting pins and measuring leakage current with and without voltage bias.

In most cases, application firmware is the most convenient way to control the GPIO pins state. It can be optimized to test only the needed pins or to run a dedicated test sequence with a test command.

The states of the GPIO pins can be controlled also with the Serial Wire Debug (SWD) debug interface. For more information, see Controlling GPIO pins with SWD.