Interrupt on falling edge

[aevznhw]

Hello community

In the pin_change_int example the following code is written:

    err_code = nrf_drv_gpiote_in_init(PIN_IN, &in_config, in_pin_handler);

So, this basically means: whenever PIN_IN goes from low to high, the 'in_pin_handler' is called.

Is there a quick and easy way to make it call the 'in_pin_handler' when PIN_IN goes from high to low (instead of low to high)? 

Thanks!

[Einar Thorsrud]

Hi,

The second parameter to nrf_drv_gpiote_in_init() is of type nrf_drv_gpiote_in_config_t, and this configures the the interrupt generation. You should configure it with one of three macros:

• GPIOTE_CONFIG_IN_SENSE_HITOLO to get an interrupt when the input goes from high to low (falling edge)
• GPIOTE_CONFIG_IN_SENSE_LOTOHI to get an interrupt when the input goes from low to high (rising edge)
• GPIOTE_CONFIG_IN_SENSE_TOGGLE to get interrupts on both edges.

So in practice, you just need to change your code to something similar to this:

    nrf_drv_gpiote_in_config_t config = GPIOTE_CONFIG_IN_SENSE_HITOLO(true);
    err_code = nrf_drv_gpiote_in_init(p_btn->pin_no, &config, gpiote_event_handler);
    VERIFY_SUCCESS(err_code);