Clarification on nPM1300 Current Measurements

RE: Clarification on nPM1300 Current Measurements

dani_martin — Tue, 04 Mar 2025 07:24:27 GMT

created devzone.nordicsemi.com/.../npm1300-ibat-0-and-adcibatmeasstatus-00

RE: Clarification on nPM1300 Current Measurements

runsiv — Mon, 03 Mar 2025 09:49:22 GMT

Hi,

please create a new ticket and we can take it there

Regards

Runar

RE: Clarification on nPM1300 Current Measurements

jimharris — Fri, 28 Feb 2025 20:20:35 GMT

I am using the code below to measure the voltage and current. Note the two second delay. It could be reduced to one second. The calls to movingAverage and get_battery_percent are not pertinent.

int npm1300_vbat_measure()

{

uint8_t temp1, temp2, temp3, temp4, temp5, temp6, temp7, temp8, temp9;

uint16_t temp16, temp17;

uint16_t lookup_value;

npm1300_write_byte(ADCCONFIG, 1); // 1 second auto measurement updates

npm1300_write_byte(TASKIBATMEASURE, 1); // 1 second auto measurement updates for IBAT

npm1300_write_byte(ADCIBATMEASEN, 1); // enable IBAT measurements

npm1300_write_byte(TASKVBATMEASURE, 1); // 1 second auto measurement updates for VBAT

npm1300_toggle_led(); // 2 second delay - mandatory

npm1300_read_byte(EVENTSADCSET, &temp3);

if (temp3) npm1300_write_byte(EVENTSADCSET,0);

npm1300_read_byte(ADCVBATRESULTMSB, &temp1);

npm1300_read_byte(ADCVBAT2RESULTMSB, &temp4);

npm1300_read_byte(ADCGP1RESULTLSBS, &temp2);

npm1300_read_byte(ADCIBATMEASSTATUS, &temp5);

npm1300_read_byte(BCHGISETMSB, &temp6);

npm1300_read_byte(BCHGISETLSB, &temp7);

npm1300_read_byte(BCHGISETDISCHARGEMSB, &temp8); // discharging current limit MSB, default is 1340mA, get MSB, LSB and multiply by 3.23

npm1300_read_byte(BCHGISETDISCHARGELSB, &temp9); // discharging current limit LSB, default is 1340mA

temp16 = temp1;

lookup_value = ((temp16 << 2)|(temp2 & 3)) << 6; // make it a 16-bit value

float vbat = lookup_value;

vbat *= 5.0;

vbat /= 1023.0;

vbat /= 64.0;

// DEBUG_PRINTF("NPM1300: VBAT MEAS: %4.2fV Lookup Value: %d Percent Remaining: %d IBAT: %04X\n", vbat, lookup_value, get_battery_percent(lookup_value), (temp4 << 1) + ((temp2 & 0x4)>> 2));

int percent = get_battery_percent(lookup_value);

temp16 = temp8; temp16 <<= 1; temp16 += temp9 & 1;

temp17 = temp4; temp17 <<= 2; temp17 += (temp2 & 0x0300) >> 8;

float ibat = temp16 * temp17;

ibat /= 1023;

float aibat = movingAverage(ibat, ibat_index);

if (ibat_index > IBAT_WINDOW_SIZE) ibat_index = IBAT_WINDOW_SIZE;

ibat_index++;

DEBUG_PRINTF("%d,%d,%02X,%02X,%02X,%02X,%4.2f,%4.2f,%4.2f\n", xTaskGetTickCount(), percent, temp1, temp4, temp2, temp5, vbat, ibat, aibat);

npm1300_write_byte(EVENTSADCCLR, 0x41);

return percent;

}

RE: Clarification on nPM1300 Current Measurements

dani_martin — Fri, 28 Feb 2025 16:00:36 GMT

Hey, I'm in a similar situation. With a npm1300 I'm able to charge (for instance, the LED showing charging status is on, BCHGCHARGESTATUS is reporting the different steps..... ) but the battery current reporting is not working properly: IBAT always 0, and ADCIBATMEASSTATUS is 00 (it should be 01 or 11).

Could you elaborate a little bit more about "f you read 00 it means that the charger is either in reset or in softstart"

Thanks!

RE: Clarification on nPM1300 Current Measurements

runsiv — Mon, 02 Dec 2024 10:21:30 GMT

Point 1 is correct

You are correct in that the current documentation do not allow you to decode the current measurement. Point 2 is correct

Point 3 is correct.

Regarding the full scale battery discharge current limit and current measurement full-scales are related but not the same. We have not provided this information the product specification. It might be possible to read out from the driver implementation but i'm not sure.

For point 4.

Can you provide all the 8 bit register that you read? We need to verify the result. If you read 00 it means that the charger is either in reset or in softstart.

Regards

Runar

RE: Clarification on nPM1300 Current Measurements

runsiv — Fri, 29 Nov 2024 11:59:34 GMT

Hi Badr

I'm looking into the issue and will need to ask internally so I will get back to you over the weekend

Regards

Runar