Gpio configuration and usage

[JohnnyMcMan]

Hello,

I am using the chip nrf52840. I am trying to configure three pins (P0.09, P0.10 and P0.11) as output pins and I am trying to make set and reset functions for them. I used the gpio_toggle example to help me do it. However, I am not doing something right even though I pretty much just copied the example code into my own project and made a few adjustments. Can some please help find me the problem? No matter what I do, the voltage of the pins on P0.10 and P0.11 is low and on P0.09 is high. The short and simple code is listed below.  Best regards.

#include "nrf_drv_spi.h"
#include "app_util_platform.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "boards.h"
#include "app_error.h"
#include <string.h>
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define CS_FLASH_MEMORY_PIN (9UL)
#define HOLD_PIN (10UL)
#define WRITE_PROTECT_PIN (11UL)

void configure_pin_direction_as_output(unsigned long pin){

NRF_GPIO->PIN_CNF[pin] = (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos) |
                         (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
                         (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |
                         (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
                         (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);

}

void set_pin(unsigned long pin){

	 NRF_GPIO->OUTSET = (1UL << pin);

}

void reset_pin(unsigned long pin){

	 NRF_GPIO->OUTCLR = (1UL << pin);

}

void configure_chip_select_pin_of_the_flash_memory(void){

  configure_pin_direction_as_output(CS_FLASH_MEMORY_PIN);

}

void configure_hold_pin_of_the_flash_memory(void){

  configure_pin_direction_as_output(HOLD_PIN);

}

void configure_write_protect_pin_of_the_flash_memory(void){

  configure_pin_direction_as_output(WRITE_PROTECT_PIN);

}

void deactivate_chip_select_pin_of_the_flash_memory(void){

  set_pin(CS_FLASH_MEMORY_PIN);

}


void activate_chip_select_pin_of_the_flash_memory(void){

  reset_pin(CS_FLASH_MEMORY_PIN);

}

void deactivate_hold_pin(void){

	set_pin(HOLD_PIN);

}

void activate_hold_pin(void){

	reset_pin(HOLD_PIN);

}

void deactivate_write_protect_pin(void){

	set_pin(WRITE_PROTECT_PIN);

}

void activate_write_protect_pin(void){

	reset_pin(WRITE_PROTECT_PIN);

}

int main(void)
{	
    
	
		deactivate_chip_select_pin_of_the_flash_memory();
	    deactivate_hold_pin();
		deactivate_write_protect_pin();
	
    while (1)
    {

    }
}

[Simonr]

Hey,

The pins P0.09 and P0.10 are by default set as NFC pins on the nRF52840. To use them as GPIOs please see the documentation provided here.

Best regards,

Simon

[JohnnyMcMan]

Hello Simonr,

Thank you for the fast reply. First of all i'm sorry, in the previous code I didn't configure the pins as output in the main loop even though I made the functions to do it. Second, I changed the GPIO pins to pins P0.17, P0.18 and P0.19. However, I still can't seem to read high voltage on those pins. This is the new code, it has a very slight difference from the code above. I try to set and reset the three pins every 6 seconds. Any suggestions why it is still not working? I am checking the voltage using my multimeter. 

Best regards

#include "nrf_drv_spi.h"
#include "app_util_platform.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"
#include "boards.h"
#include "app_error.h"
#include <string.h>
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

#define CS_FLASH_MEMORY_PIN (17UL)
#define HOLD_PIN (18UL)
#define WRITE_PROTECT_PIN (19UL)

void configure_pin_direction_as_output(unsigned long pin){

NRF_GPIO->PIN_CNF[pin] = (GPIO_PIN_CNF_DIR_Output << GPIO_PIN_CNF_DIR_Pos) |
                         (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
                         (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |
                         (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
                         (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);

}

void set_pin(unsigned long pin){

	 NRF_GPIO->OUTSET = (1UL << pin);

}

void reset_pin(unsigned long pin){

	 NRF_GPIO->OUTCLR = (1UL << pin);

}

void configure_chip_select_pin_of_the_flash_memory(void){

  configure_pin_direction_as_output(CS_FLASH_MEMORY_PIN);

}

void configure_hold_pin_of_the_flash_memory(void){

  configure_pin_direction_as_output(HOLD_PIN);

}

void configure_write_protect_pin_of_the_flash_memory(void){

  configure_pin_direction_as_output(WRITE_PROTECT_PIN);

}

void deactivate_chip_select_pin_of_the_flash_memory(void){

  set_pin(CS_FLASH_MEMORY_PIN);

}


void activate_chip_select_pin_of_the_flash_memory(void){

  reset_pin(CS_FLASH_MEMORY_PIN);

}

void deactivate_hold_pin(void){

	set_pin(HOLD_PIN);

}

void activate_hold_pin(void){

	reset_pin(HOLD_PIN);

}

void deactivate_write_protect_pin(void){

	set_pin(WRITE_PROTECT_PIN);

}

void activate_write_protect_pin(void){

	reset_pin(WRITE_PROTECT_PIN);

}

void initialize_pin_configuration_of_the_flash_memory(void){

	configure_chip_select_pin_of_the_flash_memory();
	configure_hold_pin_of_the_flash_memory();
	configure_write_protect_pin_of_the_flash_memory();

}

int main(void)
{	
	initialize_pin_configuration_of_the_flash_memory();
	
    while (1)
    {
				deactivate_chip_select_pin_of_the_flash_memory();
				deactivate_hold_pin();
				deactivate_write_protect_pin();
			
				nrf_delay_ms(6000);
			
				activate_chip_select_pin_of_the_flash_memory();
				activate_hold_pin();
				activate_write_protect_pin();
			
				nrf_delay_ms(6000);
    }
}