Correct use of NRF_LOG for display on Termite

[JK0201]

#include <stdbool.h>    //Permite usar funciones booleanas de C++
#include <stdint.h>     //Permite usar funciones generales de C++

#include "nrf.h"
#include <stdbool.h>   
#include <stdint.h>   

#include "nrf.h"
#include "nordic_common.h"
#include "boards.h"
#include "nrf_gpio.h"
#include "nrf_delay.h"  
#include "nrf_log.h"   

/**
 * @brief Function for application main entry.
 */
int main(void)
{
   nrf_gpio_cfg_input(26, NRF_GPIO_PIN_PULLDOWN);

    while (true)
    { 
				NRF_LOG_INFO(26);
    }
}
/** @} */

Hello to everyone.

I have a doubt about the function of NRF_LOG library in nRF52 DK.
I´m trying to display the voltaje value from pin P0.26 on Termite, so I saw in this page that NRF_LOG_ENABLED and NRF_LOG_BACKEND_UART_ENABLED must be in 1 on sdk_config.h, so that´s ready.
Then I try to use NRF_LOG_INFO() to display the value but I found that NRF_LOG_INFO() it´s only for char parameters.
My question is, does NRF_LOG library has a function to be used with integer value or there´s a way to convert int values into char? (line 20).
This project is the "ble_app_blinky_pca10040_s132", so contains its sdk_config.h file, but I replaced the .c file with one mine.
I hope you can help me.

[Jørgen Holmefjord]

Hi,

If you want to get the state of the pin, you need to read the pin and store its value to a variable. You can then pass the variable to NRF_LOG:

uint32_t pin_state = nrf_gpio_pin_read(26);
NRF_LOG_INFO("Pin state: %d", pin_state);

NRF_LOG use printf format to format the strings.

Best regards,
Jørgen

[Jørgen Holmefjord]

I see that you have not initialized the log module in your application. You need to add this header file to the top of main.c:

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"

and these lines in start of main-loop:

uint32_t err_code = NRF_LOG_INIT(NULL);
APP_ERROR_CHECK(err_code);

NRF_LOG_DEFAULT_BACKENDS_INIT();

[JK0201]

int main(void)
{
    // Initialize.
    log_init();
    leds_init();
    timers_init();
    buttons_init();
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();
	
	nrf_gpio_cfg_input(26, NRF_GPIO_PIN_PULLDOWN);
	uint32_t pin_state = nrf_gpio_pin_read(26);

    // Start execution.
    NRF_LOG_INFO("Blinky example started.");
	NRF_LOG_INFO("Pin state: %d", pin_state);
    advertising_start();

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}

I´m actually cheking the code with "ble_app_blinky" example, because all the configurations to use LOG are already set, but I can´t make it work. I adjusted the original code with my own lines (16, 17, 21) and only prints the message "Pin state: 0", no matter if I introduce up to 1V of power.