How do I use an external interrupt?

RE: How do I use an external interrupt?

GunMin — Mon, 09 Feb 2015 09:31:20 GMT

Thank you, Action is well.

RE: How do I use an external interrupt?

Stian Røed Hafskjold — Mon, 02 Feb 2015 21:32:18 GMT

Well, does it work?

RE: How do I use an external interrupt?

GunMin — Mon, 02 Feb 2015 17:39:47 GMT

I'm doing this? Is that right?

static void gpio_init(void)

{

  nrf_gpio_cfg_input(Record, NRF_GPIO_PIN_PULLUP);
      nrf_gpio_cfg_input(Play, NRF_GPIO_PIN_PULLUP);
  nrf_gpio_cfg_input(Menu_Dw, NRF_GPIO_PIN_PULLUP);

      NVIC_DisableIRQ(GPIOTE_IRQn);
      NVIC_ClearPendingIRQ(GPIOTE_IRQn);

       NRF_GPIOTE->CONFIG[0] =  (GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos)
                   | (0x1C << GPIOTE_CONFIG_PSEL_Pos)   
                   | (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos);
                     NRF_GPIOTE->INTENSET  = GPIOTE_INTENSET_IN0_Set << GPIOTE_INTENSET_IN0_Pos;

       NRF_GPIOTE->CONFIG[0] =  (GPIOTE_CONFIG_POLARITY_HiToLo <<                          
                           GPIOTE_CONFIG_POLARITY_Pos)
                   | (0x1D << GPIOTE_CONFIG_PSEL_Pos)   
                   | (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos);
                     NRF_GPIOTE->INTENSET  = GPIOTE_INTENSET_IN1_Set << GPIOTE_INTENSET_IN1_Pos;

  	  __NOP();
      __NOP();
      __NOP();
 
				/* Clear the event that appears in some cases */
				NRF_GPIOTE->EVENTS_IN[0] = 0; 
				NRF_GPIOTE->EVENTS_IN[1] = 0; 

      NRF_GPIOTE->INTENSET = GPIOTE_INTENSET_IN0_Enabled << GPIOTE_INTENSET_IN0_Pos;
	NRF_GPIOTE->INTENSET = GPIOTE_INTENSET_IN1_Enabled << GPIOTE_INTENSET_IN1_Pos;
        NVIC_EnableIRQ(GPIOTE_IRQn);

}

void GPIOTE_IRQHandler(void)

{

if ((NRF_GPIOTE->EVENTS_IN[0] != 0))

{

     Record_Start = (!Record_Start) ;
     NRF_GPIOTE->EVENTS_IN[0] = 0;
 }

if ((NRF_GPIOTE->EVENTS_IN[1] != 0))

{

    Record_Play = (!Record_Play) ;
    NRF_GPIOTE->EVENTS_IN[1] = 0;
}

}

RE: How do I use an external interrupt?

Stian Røed Hafskjold — Mon, 02 Feb 2015 13:37:50 GMT

This line,

NRF_GPIOTE->CONFIG[0] =  (GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos)

will cause the interrupt to trigger both when you push the button and when you release it. In order to only trigger the interrupt when you push the button, change it to:

NRF_GPIOTE->CONFIG[0] =  (GPIOTE_CONFIG_POLARITY_HiToLo<< GPIOTE_CONFIG_POLARITY_Pos)

Also, you can not read the pin state when the GPIOTE module is configured to operate on it, as you do in the interrupt handler:

if (nrf_gpio_pin_read(Record) == 0) {Record_Start = (!Record_Start);}

But, since the GPIOTE channel is now configured to only trigger on a hi to low transition, the pin will of course be low, and you can just write:

Record_Start = (!Record_Start);