read battery status using nfc with nrf52832

[pd@learner]

Hi,

I am not yet familiar with NFC.Is it possible to read battery data  from the NFC tag of the nRF52 to another device (for example a smartphone). I want to write simple application that reads battery status when the NFC tag is read by an NFC polling device, I want to write application using sdk 12.3.0 and sd132.

[Edvin]

Hello,

Yes. You can write whatever data you want to the NFC tag. Please check out the example:

SDK15.3.0\examples\nfc\record_text

Best regards,

Edvin

[pd@learner]

Thanks For quick response.

I have tried sdk12.3.0\examples\nfc\record_text. It reads 'Hello World' in three different languages. But when i am trying to read battery status every time it reads 0 value. 

[Edvin]

pd@learner said:

But when i am trying to read battery status every time it reads 0 value. 

 How exactly do you measure the battery level, and how do you pass on to the NFC?

[pd@learner]

uint8_t  percentage_batt_lvl;

void get_battery_status()
{
	saadc_init();
	nrf_drv_saadc_sample();
	nrf_delay_us(200);
	nrf_drv_saadc_uninit();
  
}
void sperNum(uint8_t sepNum, uint8_t num[])
{
   
   num[0] = sepNum%10+48;
   num[1] = (sepNum/10)%10+48;
   num[2] = (sepNum/100)+48;
   
   
}
static void en_record_add(nfc_ndef_msg_desc_t * p_ndef_msg_desc)
{
/** @snippet [NFC text usage_1] */
uint32_t err_code;

static const uint8_t en_code[] = {'e', 'n'};

uint8_t p[3];

sperNum(percentage_batt_lvl,p);

NFC_NDEF_TEXT_RECORD_DESC_DEF(en_text_rec,
UTF_8,
en_code,
sizeof(en_code),
p,
sizeof(p));
/** @snippet [NFC text usage_1] */

err_code = nfc_ndef_msg_record_add(p_ndef_msg_desc,
&NFC_NDEF_TEXT_RECORD_DESC(en_text_rec));
APP_ERROR_CHECK(err_code);

}

I have called get_battery_status function in main context  in for loop.

[Edvin]

Ok. Do you get the callback from the saadc? Does it have any values, or is it 0?

And en_text_rec, is it 0, or does it contain a value?

Have you tried debugging (turn off optimization in your project) to see where it fails?