Battery Monitoring System

soc/nordic/nrf54l/CMakeLists.txt

@@ -7,6 +7,8 @@ zephyr_library_sources(
   )
 zephyr_include_directories(.)
 
+add_subdirectory_ifdef(CONFIG_SOC_HEALTH_MONITORING health_monitoring_nrfx)
+
 dt_nodelabel(kmu_push_area_node NODELABEL nrf_kmu_reserved_push_area)
 
 # We need a buffer in memory in a static location which can be used by

soc/nordic/nrf54l/Kconfig

@@ -128,4 +128,12 @@ config SOC_NRF54L05_DEVELOP_IN_NRF54L15
 	  This symbol needs to be considered by certain system initialization functionality
 	  residing in system_nrf54l.c and SoC erratas.
 
+config VBAT_MONITOR_ENABLE
+	bool "Enable VBAT monitoring"
+	select  SOC_HEALTH_MONITORING
+
+config VINTERNAL_MONITOR_ENABLE
+	bool "Enable VInternal monitoring"
+	select  SOC_HEALTH_MONITORING
+
 endif # SOC_SERIES_NRF54L

soc/nordic/nrf54l/Kconfig.defconfig

@@ -6,6 +6,7 @@
 if SOC_SERIES_NRF54L
 
 rsource "Kconfig.defconfig.nrf54l*"
+rsource "health_monitoring_nrfx/Kconfig"
 
 if ARM
 

soc/nordic/nrf54l/health_monitoring_nrfx/CMakeLists.txt

@@ -0,0 +1,18 @@
+# Copyright (c) 2026 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+zephyr_library_sources(health_monitoring.c
+                      battery_monitor.c
+                      temperature_monitor.c)
+
+zephyr_include_directories(.)
+
+# TODO Currently this does not cause an error when enabled from Kconfig
+if (CONFIG_ADC)
+  message(FATAL_ERROR
+          "Health Monitoring feautre can not be used in conjunction with other ADC measurements,
+          see sample XXXX to implement an alternative, disabling this feature may have
+          adverse effects on performance over temperature")
+endif()

soc/nordic/nrf54l/health_monitoring_nrfx/Kconfig

@@ -0,0 +1,87 @@
+# Nordic Semiconductor nRF71 MCU line
+
+# Copyright (c) 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+config VBAT_MONITOR_ENABLE
+	bool "Enable VBAT monitoring"
+	select  SOC_HEALTH_MONITORING
+	select NRFX_SAADC
+	# select ADC # TODO: Only enable to verify error in CMakelists.txt
+
+config DIE_TEMP_MONITOR_ENABLE
+	bool "Enable die temperature monitoring"
+	select SOC_HEALTH_MONITORING
+	select SENSOR
+	select CONFIG_TEMP_NRF5
+
+config VINTERNAL_MONITOR_ENABLE
+	bool "Enable VInternal monitoring"
+	select  SOC_HEALTH_MONITORING
+
+config SOC_HEALTH_MONITORING
+	bool "Enable health monitoring system"
+	default n
+	select SOC_LATE_INIT_HOOK
+	# Debug
+	select SHELL
+	select KERNEL_SHELL
+	select LOG
+	help
+		Enable periodic VBAT voltage monitoring using SAADC.
+		When enabled, the application will periodically measure
+		the battery voltage and trigger a callback if it falls
+		below the configured threshold.
+
+if VBAT_MONITOR_ENABLE
+
+config VBAT_MONITOR_INTERVAL_MS
+	int "VBAT measurement interval (milliseconds)"
+	default 5000
+	range 100 3600000
+	help
+	  Interval between VBAT measurements in milliseconds.
+	  Minimum: 100 ms
+	  Maximum: 3600000 ms (1 hour)
+
+config VBAT_MONITOR_LOWER_THRESHOLD_MV
+	int "VBAT low threshold (millivolts)"
+	default 50
+	range 50 5000
+	help
+	  Battery voltage threshold in millivolts. When the measured
+	  voltage falls below this value, the low battery callback
+	  will be triggered.
+# TODO: Set default and voltage range to expected
+
+endif # VBAT_MONITOR_ENABLE
+
+if DIE_TEMP_MONITOR_ENABLE
+
+config DIE_TEMP_MONITOR_INTERVAL_MS
+	int "Die temperature measurement interval (milliseconds)"
+	default 3000
+	range 100 3600000
+	help
+	  Interval between die temperature measurements in milliseconds.
+	  Minimum: 100 ms
+	  Maximum: 3600000 ms (1 hour)
+
+endif # DIE_TEMP_MONITOR_ENABLE
+
+if SOC_HEALTH_MONITORING
+
+#TODO: Align this with style used elsewhere
+config HEALTH_MONITOR_LOG_LEVEL
+	int "VBAT monitor log level"
+	default 3
+	range 0 4
+	help
+	  Log level for VBAT monitor module:
+	  0 = OFF
+	  1 = ERROR
+	  2 = WARN
+	  3 = INFO
+	  4 = DEBUG
+
+endif # VBAT_MONITOR_ENABLE

soc/nordic/nrf54l/health_monitoring_nrfx/battery_monitor.c

@@ -0,0 +1,176 @@
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/logging/log.h>
+#include <nrfx_saadc.h>
+#include "battery_monitor.h"
+
+LOG_MODULE_REGISTER(battery_monitoring, CONFIG_HEALTH_MONITOR_LOG_LEVEL);
+
+#define BATTERY_CHANNEL_ID 	0
+#define VDD_VOLTAGE 		900
+/* TOOD: Map Raw value from mv and gain / resolution */
+#define VBAT_MONITOR_LOWER_THRESHOLD_RAW CONFIG_VBAT_MONITOR_LOWER_THRESHOLD_MV
+
+/** @brief global variable to store battery voltage */
+static atomic_t battery_voltage_raw;
+
+
+const nrf_saadc_channel_config_t channel_config = {.gain = NRF_SAADC_GAIN1_4,
+						   .reference = NRF_SAADC_REFERENCE_INTERNAL,
+						   .acq_time = NRFX_SAADC_DEFAULT_ACQTIME,
+						   .mode = NRF_SAADC_MODE_SINGLE_ENDED,
+						   .burst = NRF_SAADC_BURST_DISABLED};
+
+/** @brief SAADC channel to measure battery level */
+const nrfx_saadc_channel_t m_multiple_channels[] = {
+	{/* TODO: If def around for measure battery and temp ADC
+	  * Need to update to correct pins.
+	  * Also need to set Channel to measure batt (instead of external pin),
+	  * gain and divider must also be set
+	  */
+		.channel_index 	= BATTERY_CHANNEL_ID,
+		.pin_n = NRFX_ANALOG_INPUT_DISABLED,
+		.pin_p = NRFX_ANALOG_EXTERNAL_AIN4,
+		.channel_config = channel_config },
+};
+#define CHANNEL_COUNT NRFX_ARRAY_SIZE(m_multiple_channels)
+
+/** @brief Samples buffer defined with the size of @ref CHANNEL_COUNT
+ * symbol to store values from each channel ( @ref m_multiple_channels).
+ */
+static nrf_saadc_value_t m_samples_buffer[CHANNEL_COUNT];
+
+static void battery_voltage_work_handler(struct k_work *work);
+
+K_WORK_DELAYABLE_DEFINE(get_battery_voltage, battery_voltage_work_handler);
+
+/**
+ * @brief Function for getting pointer to vbatt.
+ *
+ * @return Pointer to atomic variable holding battery voltage
+ */
+atomic_t *get_battery_voltage_pointer(void)
+{
+	return &battery_voltage_raw;
+}
+
+/**
+ * @brief Function in the event battery voltage is below minimum threshold
+ *
+ */
+__weak void battery_below_threshold(void)
+{
+	LOG_WRN("IRQ LIMITL triggered on battery voltage");
+	LOG_WRN("Placeholder -  customer should implement their own requirements");
+}
+
+/**
+ * @brief Function for handling SAADC driver events.
+ *
+ * @param[in] p_event Pointer to an SAADC driver event.
+ */
+static void saadc_handler(nrfx_saadc_evt_t const *p_event)
+{
+int status;
+	uint16_t samples_number;
+	/* Temp value allows observability of functionality for reading data */
+	static int32_t voltage_temp;
+
+	switch (p_event->type) {
+	case NRFX_SAADC_EVT_DONE:
+		LOG_INF("SAADC event: DONE");
+		samples_number = p_event->data.done.size;
+		for (uint16_t i = 0; i < samples_number; i++) {
+			atomic_set(&battery_voltage_raw, 
+				NRFX_SAADC_SAMPLE_GET(p_event->data.done.p_buffer, i));
+			LOG_INF("[Raw %d] value == %ld", i, atomic_get(&battery_voltage_raw));
+			/* TODO: Map values using resolution and gain not magic numbers */
+			int battery_voltage_mv = ((VDD_VOLTAGE*4) * 
+			atomic_get(&battery_voltage_raw)) / ((1<<12));
+
+			LOG_INF("[Voltage %d] value == %d mV", i, battery_voltage_mv);
+		}
+		atomic_set(&battery_voltage_raw, voltage_temp);
+		voltage_temp++;
+		k_work_schedule(&get_battery_voltage,
+			K_MSEC(CONFIG_VBAT_MONITOR_INTERVAL_MS));
+		break;
+
+	case NRFX_SAADC_EVT_CALIBRATEDONE:
+		LOG_INF("SAADC event: CALIBRATEDONE");
+		status = nrfx_saadc_mode_trigger();
+		NRFX_ASSERT(status == 0);
+		break;
+
+	case NRFX_SAADC_EVT_LIMIT:
+		if (p_event->data.limit.limit_type == NRF_SAADC_LIMIT_LOW) {
+			if (p_event->data.limit.channel == BATTERY_CHANNEL_ID) {
+				battery_below_threshold();
+			}
+		} else {
+			LOG_WRN("Undefined Threshold event triggered");
+		}
+		break;
+
+	default:
+		break;
+	}
+}
+
+int battery_monitoring_setup(void)
+{
+	int err = 0;
+
+	// TODO: This should cause error from CMakeLists.txt
+	IRQ_CONNECT(NRFX_IRQ_NUMBER_GET(NRF_SAADC), IRQ_PRIO_LOWEST, nrfx_saadc_irq_handler, 0, 0);
+
+	err = nrfx_saadc_init(NRFX_SAADC_DEFAULT_CONFIG_IRQ_PRIORITY);
+	if (err != 0) {
+		LOG_ERR("SAADC init failed");
+		return err;
+	}
+
+	err = nrfx_saadc_channels_config(m_multiple_channels, CHANNEL_COUNT);
+	if (err != 0) {
+		LOG_ERR("SAADC channel config failed");
+		return err;
+	}
+
+	err = nrfx_saadc_simple_mode_set(nrfx_saadc_channels_configured_get(),
+					 NRF_SAADC_RESOLUTION_12BIT, NRF_SAADC_OVERSAMPLE_DISABLED,
+					 saadc_handler);
+	if (err != 0) {
+		LOG_ERR("SAADC mode setting failed");
+		return err;
+	}
+
+	err = nrfx_saadc_buffer_set(m_samples_buffer, CHANNEL_COUNT);
+	if (err != 0) {
+		LOG_ERR("Setting SAADC buffer failed");
+		return err;
+	}
+
+	err = nrfx_saadc_limits_set(BATTERY_CHANNEL_ID, VBAT_MONITOR_LOWER_THRESHOLD_RAW,
+				    INT16_MAX);
+	if (err != 0) {
+		LOG_ERR("Setting voltage limits failed failed");
+		return err;
+	}
+
+	LOG_INF("SAADC Configured");
+	k_work_schedule(&get_battery_voltage, K_MSEC(CONFIG_VBAT_MONITOR_INTERVAL_MS));
+	return err;
+}
+
+static void battery_voltage_work_handler(struct k_work *work)
+{
+	int err;
+
+	(void)work;
+
+	err = nrfx_saadc_offset_calibrate(saadc_handler);
+	if (err != 0) {
+		LOG_ERR("Offset calibration failed");
+	}
+	LOG_INF("Calibration Requested");
+}

soc/nordic/nrf54l/health_monitoring_nrfx/battery_monitor.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _BATTERY_MONITOR_H_
+#define _BATTERY_MONITOR_H_
+
+#include <zephyr/sys/atomic.h>
+
+int battery_monitoring_setup(void);
+atomic_t *get_battery_voltage_pointer(void);
+void battery_below_threshold(void);
+
+#endif /* _BATTERY_MONITOR_H_ */

soc/nordic/nrf54l/health_monitoring_nrfx/health_monitoring.c

@@ -0,0 +1,45 @@
+#include <stdlib.h>
+#include <zephyr/kernel.h>
+#include <zephyr/sys/atomic.h>
+#include <zephyr/logging/log.h>
+#include "battery_monitor.h"
+#include "temperature_monitor.h"
+
+LOG_MODULE_REGISTER(health_monitoring, CONFIG_HEALTH_MONITOR_LOG_LEVEL);
+
+typedef struct {
+	atomic_t *g_vbatt_value;
+	atomic_t *g_die_temp_value;
+} health_metrics_t;
+
+static health_metrics_t health_metrics = {};
+
+int health_monitoring_setup(void)
+{
+	int err;
+	err = battery_monitoring_setup();
+
+	if (err != 0) {
+		LOG_ERR("Battery Monitoring Setup Failed");
+		return err;
+	}
+	health_metrics.g_vbatt_value = get_battery_voltage_pointer();
+
+	err = die_temperature_monitoring_setup();
+	if (err != 0) {
+		LOG_ERR("Die Temperature Monitoring Setup Failed");
+		return err;
+	}
+	health_metrics.g_die_temp_value = get_die_temperature_pointer();
+
+//Here for now to demonstrate functionality
+	for (;;) {
+		k_sleep(K_SECONDS(2));
+		// uint32_t voltage = atomic_get(g_vbatt_value);
+		printk("Global ADC: %ld mV\n", *health_metrics.g_vbatt_value);
+		printk("Global die temp: %ld.%02u\n", *health_metrics.g_die_temp_value / 100,
+		       abs(*health_metrics.g_die_temp_value) % 100);
+	}
+
+	return 0;
+}

soc/nordic/nrf54l/health_monitoring_nrfx/health_monitoring.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef _HEALTH_MONITORING_H_
+#define _HEALTH_MONITORING_H_
+
+int health_monitoring_setup(void);
+
+#endif /* _HEALTH_MONITORING_H_ */