nPM1300: Fuel gauge

The Fuel gauge sample demonstrates how to calculate the state of charge of a development kit battery using nPM1300 and the nRF Fuel Gauge library.

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Board target

nRF9160 DK

PCA10090

nrf9160dk

nrf9160dk/nrf9160

nRF5340 DK

PCA10095

nrf5340dk

nrf5340dk/nrf5340/cpuapp

nRF52 DK

PCA10040

nrf52dk

nrf52dk/nrf52832

nRF52840 DK

PCA10056

nrf52840dk

nrf52840dk/nrf52840

The sample also requires an nPM1300 EK that you need to connect to the development kit as described in Wiring.

Overview

This sample allows to calculate the state of charge, time to empty, and time to full information from a battery on the development kit connected to the nPM1300 PMIC.

Wiring

To connect your DK to the nPM1300 EK, complete the following steps:

  1. Connect the TWI interface between the chosen DK and the nPM1300 EK as in the following table:

    nPM1300 EK connections.

    nPM1300 EK pins

    nRF52 DK pins

    nRF52840 DK pins

    nRF5340 DK pins

    nRF9160 DK pins

    SDA

    P0.26

    P0.26

    P1.02

    P0.30

    SCL

    P0.27

    P0.27

    P1.03

    P0.31

    VDDIO

    VDD

    VDD

    VDD

    VDD

    GND

    GND

    GND

    GND

    GND

  2. Make the following connections on the nPM1300 EK:

    • Connect a USB power supply to the J3 connector.

    • Connect a suitable battery to the J2 connector.

    • On the P2 pin header, connect VBAT and VBATIN pins with a jumper.

    • On the P17 pin header, connect all LEDs with jumpers.

    • On the P13 pin header, connect RSET1 and VSET1 pins with a jumper.

    • On the P14 pin header, connect RSET2 and VSET2 pins with a jumper.

Building and running

This sample can be found under samples/pmic/native/npm1300_fuel_gauge in the nRF Connect SDK folder structure.

To build the sample, follow the instructions in Configuring and building an application for your preferred building environment. See also Programming an application for programming steps and Testing and optimization for general information about testing and debugging in the nRF Connect SDK.

Note

When building repository applications in the SDK repositories, building with sysbuild is enabled by default. If you work with out-of-tree freestanding applications, you need to manually pass the --sysbuild parameter to every build command or configure west to always use it.

Testing

After programming the sample to your development kit, complete the following steps to test it:

  1. Connect the kit to the computer using a USB cable. The kit is assigned a COM port (Windows) or ttyACM device (Linux), which is visible in the Device Manager.

  2. Connect to the kit with a terminal emulator (for example, nRF Connect Serial Terminal). See Testing and optimization for the required settings and steps.

If the initialization was successful, the terminal displays the following message with status information:

PMIC device ok
V: 4.101, I: 0.000, T: 23.06, SoC: 93.09, TTE: nan, TTF: nan

Symbol

Description

Units

V

Battery voltage

Volts

I

Current

Amps (negative for charge, positive for discharge)

T

Temperature

Degrees C

SoC

State of Charge

Percent

TTE

Time to Empty

Seconds (may be NaN)

TTF

Time to Full

Seconds (may be NaN)

Dependencies

The sample uses the following sdk-nrfxlib library:

In addition, it uses the following Zephyr libraries: