Questions about example code in Github: gpio_example_main.c

[insanoff]

I am trying to understand ESP32 external interrupts so decided to test "gpio_example_main.c" example found on Github repository: https://github.com/espressif/esp-idf/bl ... ple_main.c
Some definitions are not clear to me:

• Is it necessary to disable the interrupt if the pin is output?

Code: Select all

64: io_conf.intr_type = GPIO_PIN_INTR_DISABLE;

• Why "GPIO_INPUT_IO_0" interrupt type is defined repeatedly on lines 77 and 87? Would not be sufficient to define it once?

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77: io_conf.intr_type = GPIO_PIN_INTR_POSEDGE;
87: gpio_set_intr_type(GPIO_INPUT_IO_0, GPIO_INTR_ANYEDGE);

• Why no interrupt type for "GPIO_INPUT_IO_1" is missing?

• Why ISR handler for "GPIO_INPUT_IO_0" added and then removed and added again?

Code: Select all

97: gpio_isr_handler_add(GPIO_INPUT_IO_0, gpio_isr_handler, (void*) GPIO_INPUT_IO_0);
102: gpio_isr_handler_remove(GPIO_INPUT_IO_0);
104: gpio_isr_handler_add(GPIO_INPUT_IO_0, gpio_isr_handler, (void*) GPIO_INPUT_IO_0);