nrf_gpio_read_pin doesn't seem to be working

[LuGr]

I am trying to read if an input is 0 or 1 but for some reason it takes the first one its offered and then it does not change anymore.

int main(void)
{
   nrf_gpio_cfg_output(24);
        	
   nrf_gpio_cfg_input(26, NRF_GPIO_PIN_NOPULL);	

   for(;;)
   {      
      if(nrf_gpio_pin_read(26) == 1)
      {
         nrf_gpio_pin_toggle(24);
      }
   }
}

I've also tried to read the input into a variable like this in a while/for loop:

int value = nrf_gpio_pin_read(26);

But for some reason it keeps sticking to either the first value I stored in it or the direction of the pull up/down. I'm a bit at a loss at what to try as the problem seems wierd. I have tried multiple DKs and pins to ensure it wasn't faulty hardware.

EDIT: What i want to be able to do is make something happen depending on if the input is high or low at the moment I read this. It is connected to a comparator that puts either a digital 1 or 0 value on the pin I am using as input.

EDIT: After I thought it worked last time with the code that uses a button and led on the DK I gave the comperator another go but it starts acting up again that it sets the nrf_gpio_pin_read only once in a while/for loop. When I use the code below in combination with an external comperator and I hook the comperator up to a PSU it waits for the condition while(nrf_gpio_pin_read(26) > 0) once afterwards even if I lower the voltage so this is no longer true the blinky light remains.

nrf_gpio_cfg_output(21);
nrf_gpio_cfg_input(26, NRF_GPIO_PIN_NOPULL);

int main(void)
{
	nrf_gpio_pin_write(21, 0);
	nrf_delay_ms(5000);
	
	for(;;)
	{
		while(nrf_gpio_pin_read(26) > 0)
		{
			nrf_gpio_pin_toggle(21);
			nrf_delay_ms(500);
		}
		nrf_gpio_pin_toggle(24);
	}
}

[Einar Thorsrud]

I do not see a problem with your code. Have you verified with a debugger or in another way that you always read the same value? I did a small modification to your code in order to run the code on the nRF51 DK and this code works for me:

#define BUTTON_1 17
#define LED_1 21

int main(void)
{
   nrf_gpio_cfg_output(LED_1);

   nrf_gpio_cfg_input(BUTTON_1, NRF_GPIO_PIN_PULLUP); 

   for(;;)
   {      
      if(nrf_gpio_pin_read(BUTTON_1) == 0)
      {
         nrf_gpio_pin_toggle(LED_1);
      }
   }
}

The intensity of the LED will be a bit dimmed when button 1 is pressed down, as the duty cycle of the LED will be 50% due to the toggling. When the button is not pressed the LED will either be off or glowing at 100%.

[LuGr]

I had verified the error with the debugger and an oscilloscope but after loading a couple of example projects using the read function it started to work. I am not sure what solved the problem eventually.