Handle more buttons than 4?

[mosi]

I'm trying to add more buttons to the nRF51 DK.

But I get an error.

I have found the NUMBER_OF_GPIO_TE define.

#define NUMBER_OF_GPIO_TE 4

How can I handle more buttons? I need at least 12 buttons. And my App must be able to wake up by pressing any one of them.

I found a solution in another question. I can do it like this:

void GPIOTE_IRQHandler(void)
    {
	// If PORT event has been called, clear event and do stuff
	if (NRF_GPIOTE->EVENTS_PORT)
	{
		uint32_t gpio_state = NRF_GPIO->IN;
		NRF_GPIOTE->EVENTS_PORT = 0;

		// Look at gpio_state to detect what buttons was pressed. Write code to 
        // use scheduler to transfer execution from the interrupt context to the main context 
	}
}


static void buttons_init(void)
{
	nrf_gpio_cfg_sense_input(PIN_BUTTON_X, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW);
	nrf_gpio_cfg_sense_input(PIN_BUTTON_Y, NRF_GPIO_PIN_PULLUP, NRF_GPIO_PIN_SENSE_LOW);
	NRF_GPIOTE->INTENSET = GPIOTE_INTENSET_PORT_Msk;
	NVIC_EnableIRQ(GPIOTE_IRQn);
}

I have tried this code in my application and it detects button presses and a bit in NRF_GPIOTE->EVENTS_PORT corresponding to the port number is set to zero.

I tried to find NRF_GPIOTE->EVENTS_PORT in the reference manual. I can't find any information about that register???

[John]

The reference manual just calls the register "PORT" and not "EVENTS_PORT". I think this is pretty much the norm for the manual vs. the code.