gpio_interrupt example

Example use of the GPIO driver.

This example lets you verify the functionality of GPIO pin interrupts. The "gpio0" port is used. In the pinsBitmap bitmask of the CallBackContext interrupt context, the pins from exceptionPinArr array are marked as handled so that the example can properly terminate later. All pins other than those indicated in the exceptionPinArr array are switched to the PINS_MODE state. An interrupt handler will be registered for all pins other than those indicated in the exceptionPinArr array.

In an endless loop, the example checks whether the pinsBitmap bitmask from the CallBackContext interrupt context is equal to the DONE_BITMASK bitmask (which corresponds to the condition when an interrupt has occurred on each GPIO pin). Additionally, the handler function for the latest interrupted pin is removed in the loop. When a pin is interrupted for the first time, the handler function is called, which marks the corresponding pin in the pinsBitmap bitmask in the CallBackContext interrupt context. The handler function for this pin is removed later.

Keep in mind how the example may be affected by the initial state of the registers of pull-up resistors for each pin.

Interrupts for the GPIO_EVENT_LOW_LEVEL and GPIO_EVENT_HIGH_LEVEL events are not supported.

exceptionPinArr is an array of GPIO pin numbers that need to be excluded from the example. This may be necessary if some pins are already being used for other functions, e.g. if pins are being used for a UART connection during debugging.

If you build and run this example on QEMU, an error will occur. This is the expected behavior, because there is no GPIO driver for QEMU.

If you build and run this example on Raspberry Pi 4 B, an error will occur.

Example files

The code of the example and build scripts are available at the following path:

/opt/KasperskyOS-Community-Edition-<version>/examples/gpio_interrupt

Building and running example

See Building and running examples section.