samples: shields: npm2100_ek sample

A sample show-casing the core functionalities of the nPM2100 PMIC using
the nPM2100 EK as a shield.

Signed-off-by: Sergei Ovchinnikov <sergei.ovchinnikov@nordicsemi.no>

boards/shields/npm2100_ek/npm2100_ek.overlay

@@ -43,13 +43,15 @@
 
 		npm2100_buttons: buttons {
 			compatible = "gpio-keys";
+
 			pmic_button0: pmic_button_0 {
-				gpios = < &npm2100_gpio 0 GPIO_ACTIVE_LOW>;
+				gpios = <&npm2100_gpio 0 GPIO_ACTIVE_LOW>;
 				label = "Pmic button switch 0";
 				zephyr,code = <INPUT_KEY_0>;
 			};
+
 			pmic_button1: pmic_button_1 {
-				gpios = < &npm2100_gpio 1 GPIO_ACTIVE_LOW>;
+				gpios = <&npm2100_gpio 1 GPIO_ACTIVE_LOW>;
 				label = "Pmic button switch 1";
 				zephyr,code = <INPUT_KEY_1>;
 			};

samples/shields/npm2100_ek/CMakeLists.txt

@@ -0,0 +1,12 @@
+# Copyright (c) 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+set(SHIELD npm2100_ek)
+set(EXTRA_DTC_OVERLAY_FILE npm2100_ek_buttons.overlay)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+
+project(npm2100_ek)
+target_sources(app PRIVATE src/main.c)

samples/shields/npm2100_ek/boards/nrf52840dk_nrf52840.overlay

@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&i2c0_default {
+	group1 {
+		bias-pull-up;
+	};
+};

samples/shields/npm2100_ek/boards/nrf5340dk_nrf5340_cpuapp.overlay

@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&i2c1_default {
+	group1 {
+		bias-pull-up;
+	};
+};

samples/shields/npm2100_ek/doc/index.rst

@@ -0,0 +1,147 @@
+.. zephyr:code-sample:: npm2100_ek
+   :name: nPM2100 EK
+
+   Interact with the nPM2100 PMIC using the EK buttons and the shell interface.
+
+Overview
+********
+
+This sample is provided for evaluation of the :ref:`npm2100_ek`.
+It is an example of how the nPM2100 GPIO pins and the shell
+interface can be used to control the following features:
+
+   - Regulators (BOOST, LDOSW)
+   - GPIO
+
+Requirements
+************
+
+The sample supports the following boards: :zephyr:board:`nrf52840dk`, :zephyr:board:`nrf5340dk`
+
+The sample also requires an nPM2100 Evaluation Kit (EK) that you need to connect to the
+development kit as described in `Wiring`_.
+
+Wiring
+******
+
+With this configuration, the nPM2100 EK is wired to supply power to the DK.
+This ensures that the TWI communication is at compatible voltage level, and represents a realistic use case for the nPM2100 PMIC.
+
+.. note::
+
+   To prevent leakage currents and program the DK, do not remove the USB connection.
+
+   Unplug the battery from the nPM2100 EK and set the DK power switch to "OFF" while
+   applying the wiring.
+   If you have issues communicating with the DK or programming it after applying the wiring, try to power cycle the DK and EK.
+
+To connect your DK to the nPM2100 EK, complete the following steps:
+
+#. Prepare the DK for being powered by the nPM2100 EK:
+
+   - Set switch **SW9** ("nRF power source") to position "VDD".
+   - Set switch **SW10** ("VEXT -> VnRF") to position "ON".
+
+#. Connect the TWI interface and power supply between the chosen DK and the nPM2100 EK
+   as described in the following table:
+
+   +------------------+-------+-------+-----------------------+-----+
+   | nPM2100 EK pins  |  SDA  |  SCL  |         VOUT          | GND |
+   +------------------+-------+-------+-----------------------+-----+
+   | nRF52840 DK pins | P0.26 | P0.27 | P21 External supply + | GND |
+   +------------------+-------+-------+-----------------------+-----+
+   | nRF5340 DK pins  | P1.02 | P1.03 | P21 External supply + | GND |
+   +------------------+-------+-------+-----------------------+-----+
+
+#. Make the following connections on the nPM2100 EK:
+
+   - Remove the USB power supply from the **J4** connector.
+   - On the **P6** pin header, connect pins 1 and 2 with a jumper.
+   - On the **BOOTMON** pin header, select **OFF** with a jumper.
+   - On the **VSET** pin header, select **3.0V** with a jumper.
+   - On the **VBAT SEL** switch, select **VBAT** position.
+   - Connect a battery board to the **BATTERY INPUT** connector.
+
+Building and Running
+********************
+
+To build the sample use the following command:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/shields/npm2100_ek
+   :board: nrf52840dk/nrf52840
+   :goals: build
+   :compact:
+
+.. note::
+   This sample automatically sets the ``SHIELD`` to ``npm2100_ek``.
+   Once you have flashed the software to your device, boot into the shell interface.
+   Use the ``regulator`` command to test the PMIC.
+   See the following section for details on the subcommands.
+
+Regulator control
+*****************
+
+If the initialization was successful, the terminal displays the following message
+with status information:
+
+.. code-block:: console
+
+   PMIC device ok
+
+The sample also reports the battery and boost output voltages as well as the die
+temperature measured every two seconds.
+
+Use the buttons on the EK to control the regulators as follows:
+
++---------------------------+----------------------------------+
+| Operation                 | Outcome                          |
++---------------------------+----------------------------------+
+| Button **GPIO0** pressed  | BOOST output forced into HP mode |
++---------------------------+----------------------------------+
+| Button **GPIO0** released | BOOST output operates in LP mode |
++---------------------------+----------------------------------+
+| Button **GPIO1** pressed  | Load Switch on                   |
++---------------------------+----------------------------------+
+| Button **GPIO1** released | Load Switch off                  |
++---------------------------+----------------------------------+
+
+The ``regulator`` shell interface provides several subcommand to test
+the regulators embedded in the PMIC.
+
+To list all supported voltages for a regulator, run the following command:
+
+.. code-block:: console
+
+   uart:~$ regulator vlist BOOST
+   1.800000 V
+   1.850000 V
+   ...
+
+To enable or disable a regulator, run the following commands:
+
+.. code-block:: console
+
+   uart:~$ regulator enable LDOSW
+   uart:~$ regulator disable LDOSW
+
+.. note::
+   The BOOST regulator is always enabled.
+
+To set the output voltage of a regulator, run the following command:
+
+.. code-block:: console
+
+   uart:~$ regulator vset BOOST 2.5v
+   uart:~$ regulator vget BOOST
+   2.500000 V
+
+.. note::
+   The BOOST regulator cannot provide a voltage lower than the battery voltage.
+
+To get the GPIO status, run the following command:
+
+.. code-block:: console
+
+   uart:~$ gpio get npm2100_gpio 0
+   0

samples/shields/npm2100_ek/npm2100_ek_buttons.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* Set GPIO pins as inputs controlling features of the respective regulators */
+
+&npm2100_boost {
+	mode-gpios = <&npm2100_gpio 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
+};
+
+&npm2100_ldosw {
+	mode-gpios = <&npm2100_gpio 1 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
+};

samples/shields/npm2100_ek/prj.conf

@@ -0,0 +1,17 @@
+# Copyright (c) 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+CONFIG_SHELL=y
+CONFIG_LOG=y
+CONFIG_LOG_CMDS=y
+CONFIG_GPIO=y
+CONFIG_GPIO_SHELL=y
+CONFIG_REGULATOR=y
+CONFIG_REGULATOR_SHELL=y
+CONFIG_WATCHDOG=y
+CONFIG_WDT_SHELL=y
+CONFIG_SENSOR=y
+CONFIG_SENSOR_SHELL=y
+CONFIG_I2C=y
+CONFIG_I2C_SHELL=y
+CONFIG_I2C_LOG_LEVEL_WRN=y

samples/shields/npm2100_ek/sample.yaml

@@ -0,0 +1,10 @@
+# Copyright (c) 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+sample:
+  name: nPM2100 EK
+tests:
+  sample.shields.npm2100_ek:
+    harness: shield
+    tags: shield
+    depends_on: arduino_i2c

samples/shields/npm2100_ek/src/main.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/regulator.h>
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/dt-bindings/regulator/npm2100.h>
+
+#define UPDATE_TIME_MS 2000
+
+static const struct device *boost = DEVICE_DT_GET(DT_NODELABEL(npm2100_boost));
+static const struct device *ldosw = DEVICE_DT_GET(DT_NODELABEL(npm2100_ldosw));
+static const struct device *vbat = DEVICE_DT_GET(DT_NODELABEL(npm2100_vbat));
+
+int setup_regulators(void)
+{
+	int err;
+
+	/* boost to operate in Low Power mode by default, force High Power on GPIO0 active */
+	err = regulator_set_mode(boost, NPM2100_REG_OPER_LP | NPM2100_REG_FORCE_HP);
+	if (err != 0) {
+		return err;
+	}
+
+	/* LDOSW to operate as a Load Switch: off by default, on when GPIO1 active */
+	err = regulator_set_mode(ldosw,
+				 NPM2100_REG_OPER_OFF | NPM2100_REG_FORCE_HP | NPM2100_REG_LDSW_EN);
+	if (err != 0) {
+		return err;
+	}
+
+	return regulator_enable(ldosw);
+}
+
+void display_sensor_values(void)
+{
+	struct sensor_value v_battery;
+	struct sensor_value v_out;
+	struct sensor_value temp;
+
+	sensor_sample_fetch(vbat);
+	sensor_channel_get(vbat, SENSOR_CHAN_GAUGE_VOLTAGE, &v_battery);
+	sensor_channel_get(vbat, SENSOR_CHAN_VOLTAGE, &v_out);
+	sensor_channel_get(vbat, SENSOR_CHAN_DIE_TEMP, &temp);
+
+	printk("VBat: %d.%03d ", v_battery.val1, v_battery.val2 / 1000);
+	printk("VOut: %d.%03d ", v_out.val1, v_out.val2 / 1000);
+	printk("T: %s%d.%02d\n", ((temp.val1 < 0) || (temp.val2 < 0)) ? "-" : "", abs(temp.val1),
+	       abs(temp.val2) / 10000);
+}
+
+int main(void)
+{
+	int err;
+
+	if (!device_is_ready(ldosw)) {
+		printk("Error: LDOSW device is not ready\n");
+		return -ENODEV;
+	}
+
+	if (!device_is_ready(boost)) {
+		printk("Error: BOOST device is not ready\n");
+		return -ENODEV;
+	}
+
+	if (!device_is_ready(vbat)) {
+		printk("Error: vbat device is not ready\n");
+		return -ENODEV;
+	}
+
+	err = setup_regulators();
+	if (err != 0) {
+		printk("Error: failed to set regulator modes\n");
+		return err;
+	}
+
+	printk("PMIC device ok\n");
+
+	while (1) {
+		display_sensor_values();
+		k_msleep(UPDATE_TIME_MS);
+	}
+}