Battery measurement, basic version

firmware/VERSION

@@ -1,6 +1,6 @@
 VERSION_MAJOR = 0
 VERSION_MINOR = 0
-PATCHLEVEL = 6
+PATCHLEVEL = 13
 VERSION_TWEAK = 0
 #if (IS_ENABLED(CONFIG_LOG))
 EXTRAVERSION = debug

firmware/boards/iten/buzzy/buzzy.dts

@@ -54,7 +54,7 @@
 	charger_status {
 		compatible = "gpio-keys";
 		chg_status: chg_status {
-			gpios = <&gpio0 13 GPIO_ACTIVE_HIGH>;
+			gpios = <&gpio0 13 (GPIO_ACTIVE_HIGH | GPIO_PULL_UP)>;
 			label = "ETA6003_CHG_STATUS";
 		};
 	};

firmware/build_output.txt

@@ -0,0 +1,2 @@
+ERROR: Build directory /Users/edi/nrf_playground/buzzer_2/firmware/build targets board buzzy/nrf52840, but board {self.args.board} was specified. (Clean the directory, use --pristine, or use --build-dir to specify a different one.)
+FATAL ERROR: refusing to proceed without --force due to above error

firmware/debug.conf

@@ -8,8 +8,16 @@ CONFIG_DEBUG_OPTIMIZATIONS=y
 CONFIG_INIT_STACKS=y
 CONFIG_THREAD_STACK_INFO=y
 
-### Bluetooth subsystem logging (reduced noise)
+### Lib logging levels
-CONFIG_BT_LOG_LEVEL_WRN=y
+CONFIG_BATT_MGMT_LOG_LEVEL_DBG=y
+CONFIG_USB_MGMT_LOG_LEVEL_DBG=y
+
+### Bluetooth
+CONFIG_BLE_MGMT=n
+CONFIG_BT_LOG_LEVEL_WRN=n
+
+### Audio
+CONFIG_BUZZ_AUDIO=n
 
 ### Shell features shared by all debug variants
 CONFIG_SHELL=y

firmware/libs/CMakeLists.txt

@@ -5,3 +5,5 @@ add_subdirectory(ble_mgmt)
 add_subdirectory(buzz_proto)
 add_subdirectory(audio)
 add_subdirectory(event_mgmt)
+add_subdirectory(batt_mgmt)
+add_subdirectory(usb_mgmt)

firmware/libs/Kconfig

@@ -5,3 +5,5 @@ rsource "ble_mgmt/Kconfig"
 rsource "buzz_proto/Kconfig"
 rsource "audio/Kconfig"
 rsource "event_mgmt/Kconfig"
+rsource "batt_mgmt/Kconfig"
+rsource "usb_mgmt/Kconfig"

firmware/libs/batt_mgmt/CMakeLists.txt

@@ -0,0 +1,5 @@
+if(CONFIG_BATT_MGMT)
+  zephyr_library()
+  zephyr_library_sources(src/batt_mgmt.c)
+  zephyr_include_directories(include)
+endif()

firmware/libs/batt_mgmt/Kconfig

@@ -0,0 +1,63 @@
+menuconfig BATT_MGMT
+    bool "Battery Management"
+    default y
+    select ADC
+    select GPIO
+    select USB_MGMT
+    help
+      Library for initializing and managing the battery subsystem.
+
+if BATT_MGMT
+    config BATT_MGMT_FULL_THRESHOLD
+        int "Battery Full Voltage (mV)"
+        default 3980
+        help
+          Set the voltage level (in millivolts) that represents a full battery. Default is 3980 mV.
+    
+    config BATT_MGMT_80P_THRESHOLD
+        int "Battery 80% Voltage (mV)"
+        default 3820
+        help
+          Set the voltage level (in millivolts) that represents 80% battery. Default is 3820 mV.
+    
+    config BATT_MGMT_50P_THRESHOLD
+        int "Battery 50% Voltage (mV)"
+        default 3720
+        help
+          Set the voltage level (in millivolts) that represents 50% battery. Default is 3720 mV.
+
+    config BATT_MGMT_20P_THRESHOLD
+        int "Battery 20% Voltage (mV)"
+        default 3620
+        help
+          Set the voltage level (in millivolts) that represents 20% battery. Default is 3620 mV.
+
+    config BATT_MGMT_CHG_BLINKING_WINDOW_MS
+        int "Charger blinking detection window (ms)"
+        default 700
+        help
+          Time window to detect charger pin blinking (state changes). If the pin state
+          changes within this window, it's considered blinking (error state).
+
+    config BATT_MGMT_MONITOR_THREAD_STACK_SIZE
+        int "Battery monitor thread stack size"
+        default 1024
+        help
+          Stack size for the USB-triggered charger status monitor thread.
+
+    config BATT_MGMT_MONITOR_THREAD_PRIORITY
+        int "Battery monitor thread priority"
+        default 7
+        help
+          Cooperative priority for the monitor thread (lower number = higher priority).
+
+    config BATT_MGMT_BLINK_INTERVAL_LOGGING
+        bool "Enable logging of charger pin blinking intervals"
+        default n
+        help
+          If enabled, logs the time intervals between charger pin state changes, which can help diagnose charger connection issues.
+
+    module = BATT_MGMT
+    module-str = batt_mgmt
+    source "subsys/logging/Kconfig.template.log_config"
+endif # BATT_MGMT

firmware/libs/batt_mgmt/include/batt_mgmt.h

@@ -0,0 +1,52 @@
+#ifndef BATT_MGMT_H
+#define BATT_MGMT_H
+
+#include <zephyr/types.h>
+#include <stdbool.h>
+
+#define BATT_MGMT_OVERSAMPLING_8X 8U
+#define BATT_MGMT_OVERSAMPLING_16X 16U
+
+typedef enum {
+	BATT_STATE_DISCHARGING = 0,
+	BATT_STATE_FULL,
+	BATT_STATE_CHARGING,
+	BATT_STATE_ERROR,
+	BATT_STATE_UNKNOWN,
+} batt_mgmt_state_t;
+
+/**
+ * @brief Measure battery VDDH voltage.
+ *
+ * @param oversampling Oversampling factor (BATT_MGMT_OVERSAMPLING_8X or BATT_MGMT_OVERSAMPLING_16X).
+ * @param vddh_mv Pointer to store the result in millivolts.
+ * @return 0 on success, negative errno on failure.
+ */
+int batt_mgmt_measure_vddh_mv(uint8_t oversampling, int32_t *vddh_mv);
+
+/**
+ * @brief Get raw charger status (GPIO level).
+ *
+ * Returns the current logic level of the charger status pin (typically from ETA6003).
+ * This is the **raw GPIO status**, not a processed state machine result.
+ *
+ * @return true if charger pin is high (e.g., battery is "full"), false if low.
+ */
+bool batt_mgmt_get_charger_status(void);
+
+/**
+ * @brief Get processed battery state with blinking detection.
+ *
+ * Returns a derived state based on:
+ * - USB VBUS presence (from usb_mgmt)
+ * - Charger status GPIO level (from batt_mgmt_get_charger_status)
+ * - Blinking detection (state changes within CONFIG_BATT_MGMT_CHG_BLINKING_WINDOW_MS)
+ *
+ * Note: This differs from batt_mgmt_get_charger_status() which returns the **raw** GPIO level.
+ *
+ * @return Battery state enum (DISCHARGING, FULL, CHARGING, or ERROR if blinking detected).
+ */
+batt_mgmt_state_t batt_mgmt_get_battery_state(void);
+
+#endif
+

firmware/libs/batt_mgmt/src/batt_mgmt.c

@@ -0,0 +1,313 @@
+#include <zephyr/device.h>
+#include <zephyr/drivers/adc.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/init.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+#include <errno.h>
+#include <stdbool.h>
+
+#include "batt_mgmt.h"
+#include "usb_mgmt.h"
+
+LOG_MODULE_REGISTER(batt_mgmt, CONFIG_BATT_MGMT_LOG_LEVEL);
+
+#define BATT_VDDH_DIVIDER_FACTOR 5
+
+#define BATT_VDDH_ADC_NODE DT_PATH(zephyr_user)
+static const struct adc_dt_spec batt_vddh_adc = ADC_DT_SPEC_GET_BY_NAME(BATT_VDDH_ADC_NODE, vddh);
+
+#define BATT_CHG_STATUS_NODE DT_ALIAS(chg_status)
+static const struct gpio_dt_spec batt_chg_status = GPIO_DT_SPEC_GET(BATT_CHG_STATUS_NODE, gpios);
+
+static bool batt_mgmt_ready;
+static int64_t batt_mgmt_last_chg_change_ms;
+static bool batt_mgmt_chg_interrupt_enabled;
+static K_THREAD_STACK_DEFINE(batt_monitor_stack, CONFIG_BATT_MGMT_MONITOR_THREAD_STACK_SIZE);
+static struct k_thread batt_monitor_thread_data;
+
+static int batt_mgmt_to_adc_oversampling(uint8_t oversampling, uint8_t *adc_oversampling)
+{
+	if (adc_oversampling == NULL)
+	{
+		return -EINVAL;
+	}
+
+	switch (oversampling)
+	{
+	case BATT_MGMT_OVERSAMPLING_8X:
+		*adc_oversampling = 3U;
+		return 0;
+	case BATT_MGMT_OVERSAMPLING_16X:
+		*adc_oversampling = 4U;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+int batt_mgmt_measure_vddh_mv(uint8_t oversampling, int32_t *vddh_mv)
+{
+	int rc;
+	uint8_t adc_oversampling;
+	int16_t raw_sample;
+	int32_t input_mv;
+	struct adc_sequence sequence = {
+		.buffer = &raw_sample,
+		.buffer_size = sizeof(raw_sample),
+	};
+
+	if (vddh_mv == NULL)
+	{
+		return -EINVAL;
+	}
+
+	if (!batt_mgmt_ready)
+	{
+		return -EAGAIN;
+	}
+
+	rc = batt_mgmt_to_adc_oversampling(oversampling, &adc_oversampling);
+	if (rc < 0)
+	{
+		return rc;
+	}
+
+	rc = adc_sequence_init_dt(&batt_vddh_adc, &sequence);
+	if (rc < 0)
+	{
+		return rc;
+	}
+
+	sequence.oversampling = adc_oversampling;
+
+	rc = adc_read_dt(&batt_vddh_adc, &sequence);
+	if (rc < 0)
+	{
+		return rc;
+	}
+
+	input_mv = raw_sample;
+	rc = adc_raw_to_millivolts_dt(&batt_vddh_adc, &input_mv);
+	if (rc < 0)
+	{
+		return rc;
+	}
+
+	*vddh_mv = input_mv * BATT_VDDH_DIVIDER_FACTOR;
+
+	LOG_DBG("Battery VDDH: %d mV (raw=%d, os=%ux)", *vddh_mv, raw_sample, oversampling);
+	return 0;
+}
+
+static void batt_mgmt_chg_interrupt_handler(const struct device *dev,
+											struct gpio_callback *cb,
+											uint32_t pins)
+{
+	int64_t now_ms = k_uptime_get();
+	int64_t delta_ms = now_ms - batt_mgmt_last_chg_change_ms;
+
+#ifdef CONFIG_BATT_MGMT_BLINK_INTERVAL_LOGGING
+	LOG_DBG("CHG interrupt: delta=%lld ms", delta_ms);
+#endif
+
+	batt_mgmt_last_chg_change_ms = now_ms;
+}
+
+static int batt_mgmt_enable_chg_interrupt(void)
+{
+	int rc;
+	static struct gpio_callback batt_chg_cb;
+
+	if (batt_mgmt_chg_interrupt_enabled)
+	{
+		return 0;
+	}
+
+	if (!gpio_is_ready_dt(&batt_chg_status))
+	{
+		LOG_ERR("CHG GPIO device not ready");
+		return -ENODEV;
+	}
+
+	rc = gpio_pin_configure_dt(&batt_chg_status, GPIO_INPUT);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to configure CHG GPIO: %d", rc);
+		return rc;
+	}
+
+	gpio_init_callback(&batt_chg_cb, batt_mgmt_chg_interrupt_handler, BIT(batt_chg_status.pin));
+	rc = gpio_add_callback(batt_chg_status.port, &batt_chg_cb);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to add CHG callback: %d", rc);
+		return rc;
+	}
+
+	rc = gpio_pin_interrupt_configure_dt(&batt_chg_status, GPIO_INT_EDGE_BOTH);
+	if (rc < 0)
+	{
+		LOG_ERR("Failed to configure CHG interrupt: %d", rc);
+		return rc;
+	}
+
+	batt_mgmt_chg_interrupt_enabled = true;
+	batt_mgmt_last_chg_change_ms = k_uptime_get();
+	LOG_INF("CHG interrupt enabled");
+
+	return 0;
+}
+
+static int batt_mgmt_disable_chg_interrupt(void)
+{
+	int rc;
+
+	if (!batt_mgmt_chg_interrupt_enabled)
+	{
+		return 0;
+	}
+
+	rc = gpio_pin_interrupt_configure_dt(&batt_chg_status, GPIO_INT_DISABLE);
+	if (rc < 0)
+	{
+		LOG_WRN("Failed to disable CHG interrupt: %d", rc);
+		return rc;
+	}
+
+	rc = gpio_pin_configure(batt_chg_status.port, batt_chg_status.pin, GPIO_DISCONNECTED);
+	if (rc < 0)
+	{
+		LOG_WRN("Failed to disconnect CHG GPIO: %d", rc);
+		return rc;
+	}
+
+	batt_mgmt_chg_interrupt_enabled = false;
+	LOG_DBG("CHG interrupt disabled");
+
+	return 0;
+}
+
+bool batt_mgmt_get_charger_status(void)
+{
+	if (!batt_mgmt_chg_interrupt_enabled)
+	{
+		return false;
+	}
+
+	return gpio_pin_get_dt(&batt_chg_status);
+}
+
+batt_mgmt_state_t batt_mgmt_get_battery_state(void)
+{
+	int64_t now_ms = k_uptime_get();
+	int64_t delta_ms = now_ms - batt_mgmt_last_chg_change_ms;
+	bool chg_high = batt_mgmt_get_charger_status();
+	bool usb_present = usb_mgmt_is_vbus_present();
+
+	/* Blinking detection: state change within window */
+	if (delta_ms < CONFIG_BATT_MGMT_CHG_BLINKING_WINDOW_MS)
+	{
+		LOG_DBG("Blinking detected (delta=%lld ms)", delta_ms);
+		return BATT_STATE_ERROR;
+	}
+
+	/* Stable states */
+	if (chg_high)
+	{
+		return BATT_STATE_CHARGING;
+	}
+
+	if (usb_present)
+	{
+		return BATT_STATE_FULL;
+	}
+
+	return BATT_STATE_DISCHARGING;
+}
+
+static void batt_mgmt_monitor_thread(void *unused1, void *unused2, void *unused3)
+{
+	(void)unused1;
+	(void)unused2;
+	(void)unused3;
+
+	if (!usb_mgmt_wait_ready(K_SECONDS(2)))
+	{
+		LOG_WRN("usb_mgmt not ready after timeout; using current VBUS state");
+	}
+
+	/* Sync initial state in case VBUS was already present before this thread started. */
+	bool vbus_present = usb_mgmt_is_vbus_present();
+
+	if (vbus_present)
+	{
+		(void)batt_mgmt_enable_chg_interrupt();
+	}
+	else
+	{
+		(void)batt_mgmt_disable_chg_interrupt();
+	}
+
+	while (1)
+	{
+		uint32_t events = k_event_wait(&usb_mgmt_events,
+									   USB_MGMT_VBUS_CONNECTED | USB_MGMT_VBUS_DISCONNECTED,
+									   false, K_FOREVER);
+
+		if (events & USB_MGMT_VBUS_CONNECTED)
+		{
+			(void)batt_mgmt_enable_chg_interrupt();
+		}
+
+		if (events & USB_MGMT_VBUS_DISCONNECTED)
+		{
+			(void)batt_mgmt_disable_chg_interrupt();
+		}
+
+		k_event_clear(&usb_mgmt_events, USB_MGMT_VBUS_CONNECTED | USB_MGMT_VBUS_DISCONNECTED);
+	}
+}
+
+static int batt_mgmt_init(void)
+{
+	int32_t boot_vddh_mv;
+	int rc;
+
+	if (!adc_is_ready_dt(&batt_vddh_adc))
+	{
+		LOG_ERR("VDDH ADC device not ready");
+		return -ENODEV;
+	}
+
+	rc = adc_channel_setup_dt(&batt_vddh_adc);
+	if (rc < 0)
+	{
+		LOG_ERR("VDDH ADC channel setup failed: %d", rc);
+		return rc;
+	}
+
+	batt_mgmt_ready = true;
+
+	rc = batt_mgmt_measure_vddh_mv(BATT_MGMT_OVERSAMPLING_16X, &boot_vddh_mv);
+	if (rc < 0)
+	{
+		LOG_WRN("Initial battery measurement failed: %d", rc);
+		return 0;
+	}
+
+	LOG_DBG("Initial battery VDDH: %d mV", boot_vddh_mv);
+
+	k_thread_create(&batt_monitor_thread_data,
+					batt_monitor_stack,
+					K_THREAD_STACK_SIZEOF(batt_monitor_stack),
+					batt_mgmt_monitor_thread,
+					NULL, NULL, NULL,
+					K_PRIO_COOP(CONFIG_BATT_MGMT_MONITOR_THREAD_PRIORITY),
+					0, K_NO_WAIT);
+
+	return 0;
+}
+
+SYS_INIT(batt_mgmt_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);

firmware/libs/settings_mgmt/src/settings_mgmt.c

@@ -27,7 +27,11 @@ LOG_MODULE_REGISTER(settings_mgmt, LOG_LEVEL_INF);
 
 /* The "Source of Truth" in RAM */
 struct app_settings_t app_cfg = {
+#ifdef CONFIG_BLE_MGMT_DEFAULT_DEVICE_NAME
     .dev_name = CONFIG_BLE_MGMT_DEFAULT_DEVICE_NAME,
+#else
+    .dev_name = CONFIG_BOARD, /* Default to board name if no explicit default set */
+#endif
     .vol = 100,               /* 0-100 % */
     .shuffle_mode = 0,
     .ble_timeout = 0xFFFFFFFF,

firmware/libs/usb_mgmt/CMakeLists.txt

@@ -0,0 +1,5 @@
+if(CONFIG_USB_MGMT)
+  zephyr_library()
+  zephyr_library_sources(src/usb_mgmt.c)
+  zephyr_include_directories(include)
+endif()

firmware/libs/usb_mgmt/Kconfig

@@ -0,0 +1,13 @@
+menuconfig USB_MGMT
+    bool "USB Management"
+    default y
+    select NRFX_POWER
+    help
+      Library for USB-related queries, e.g. VBUS presence detection
+      via the nRF52840 POWER peripheral.
+
+if USB_MGMT
+    module = USB_MGMT
+    module-str = usb_mgmt
+    source "subsys/logging/Kconfig.template.log_config"
+endif # USB_MGMT

firmware/libs/usb_mgmt/include/usb_mgmt.h

@@ -0,0 +1,30 @@
+#ifndef USB_MGMT_H
+#define USB_MGMT_H
+
+#include <stdbool.h>
+#include <zephyr/kernel.h>
+
+#define USB_MGMT_VBUS_CONNECTED BIT(0)
+#define USB_MGMT_VBUS_DISCONNECTED BIT(1)
+
+extern struct k_event usb_mgmt_events;
+
+/**
+ * @brief Wait until usb_mgmt has completed initialization.
+ *
+ * @param timeout Timeout for waiting.
+ *
+ * @retval true usb_mgmt is ready.
+ * @retval false timeout occurred.
+ */
+bool usb_mgmt_wait_ready(k_timeout_t timeout);
+
+/**
+ * @brief Returns true when VBUS (USB 5 V) is present.
+ *
+ * Reads the USBREGSTATUS.VBUSDETECT bit in the nRF52840 POWER peripheral.
+ * No USB stack needs to be enabled.
+ */
+bool usb_mgmt_is_vbus_present(void);
+
+#endif /* USB_MGMT_H */

firmware/libs/usb_mgmt/src/usb_mgmt.c

@@ -0,0 +1,65 @@
+#include <hal/nrf_power.h>
+#include <nrfx_power.h>
+#include <errno.h>
+#include <zephyr/logging/log.h>
+
+#include "usb_mgmt.h"
+
+LOG_MODULE_REGISTER(usb_mgmt, CONFIG_USB_MGMT_LOG_LEVEL);
+
+K_EVENT_DEFINE(usb_mgmt_events);
+K_SEM_DEFINE(usb_mgmt_ready_sem, 0, 1);
+
+static bool usb_mgmt_last_vbus_state;
+static bool usb_mgmt_ready;
+
+static void usb_mgmt_power_handler(nrfx_power_usb_evt_t event)
+{
+	bool is_present = (event == NRFX_POWER_USB_EVT_DETECTED);
+
+	LOG_INF("VBUS %s (event=%u)", is_present ? "connected" : "disconnected", event);
+
+	if (is_present != usb_mgmt_last_vbus_state) {
+		usb_mgmt_last_vbus_state = is_present;
+		k_event_post(&usb_mgmt_events,
+			     is_present ? USB_MGMT_VBUS_CONNECTED : USB_MGMT_VBUS_DISCONNECTED);
+	}
+}
+
+static int usb_mgmt_init(void)
+{
+	usb_mgmt_last_vbus_state = nrf_power_usbregstatus_vbusdet_get(NRF_POWER);
+	LOG_DBG("Boot VBUS state: %s", usb_mgmt_last_vbus_state ? "present" : "absent");
+	k_event_post(&usb_mgmt_events,
+		     usb_mgmt_last_vbus_state ? USB_MGMT_VBUS_CONNECTED : USB_MGMT_VBUS_DISCONNECTED);
+
+	nrfx_power_config_t config = { 0 };
+	nrfx_power_usbevt_config_t usb_config = {
+		.handler = usb_mgmt_power_handler,
+	};
+
+	nrfx_power_init(&config);
+	nrfx_power_usbevt_init(&usb_config);
+	nrfx_power_usbevt_enable();
+
+	usb_mgmt_ready = true;
+	k_sem_give(&usb_mgmt_ready_sem);
+
+	return 0;
+}
+
+SYS_INIT(usb_mgmt_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);
+
+bool usb_mgmt_is_vbus_present(void)
+{
+	return usb_mgmt_last_vbus_state;
+}
+
+bool usb_mgmt_wait_ready(k_timeout_t timeout)
+{
+	if (usb_mgmt_ready) {
+		return true;
+	}
+
+	return k_sem_take(&usb_mgmt_ready_sem, timeout) == 0;
+}

firmware/output.txt

@@ -0,0 +1,2 @@
+ERROR: Build directory /Users/edi/nrf_playground/buzzer_2/firmware/build targets board buzzy/nrf52840, but board {self.args.board} was specified. (Clean the directory, use --pristine, or use --build-dir to specify a different one.)
+FATAL ERROR: refusing to proceed without --force due to above error

firmware/prj.conf

@@ -1,9 +1,3 @@
-### Bluetooth
-CONFIG_BLE_MGMT=y
-
-### Audio
-CONFIG_BUZZ_AUDIO=n
-
 ### Error handling
 CONFIG_HW_STACK_PROTECTION=y
 CONFIG_RESET_ON_FATAL_ERROR=y
@@ -11,6 +5,9 @@ CONFIG_RESET_ON_FATAL_ERROR=y
 ### Power management
 CONFIG_PM_DEVICE=y
 
+### Boot banner
+CONFIG_NCS_APPLICATION_BOOT_BANNER_STRING="Edis Buzzer"
+
 ### Stack
 CONFIG_MAIN_STACK_SIZE=2048
 CONFIG_BT_RX_STACK_SIZE=4096

firmware/rtt_script.jlink

@@ -0,0 +1,5 @@
+connect
+rtt start
+sleep 3000
+rtt stop
+exit

firmware/src/main.c

@@ -4,11 +4,28 @@
 
 #include "buzz_proto.h"
 #include "settings_mgmt.h"
+#include "batt_mgmt.h"
 // #include "fw_mgmt.h"
 // #include "audio.h"
 
 LOG_MODULE_REGISTER(main);
 
+static const char *battery_state_to_str(batt_mgmt_state_t state)
+{
+    switch (state) {
+    case BATT_STATE_DISCHARGING:
+        return "discharging";
+    case BATT_STATE_FULL:
+        return "full";
+    case BATT_STATE_CHARGING:
+        return "charging";
+    case BATT_STATE_ERROR:
+        return "error";
+    default:
+        return "unknown";
+    }
+}
+
 #if IS_ENABLED(CONFIG_BLE_MGMT)
 #include "ble_mgmt.h"
 void ble_rx_cb(const uint8_t *data, uint16_t len)
@@ -49,6 +66,7 @@ void ble_rx_cb(const uint8_t *data, uint16_t len)
 
 int main(void)
 {
+
 #if IS_ENABLED(CONFIG_BLE_MGMT)
     /* BLE-Subsystem initialisieren und RX-Callback registrieren */
     int rc = ble_mgmt_init(ble_rx_cb, app_cfg.dev_name);
@@ -56,17 +74,25 @@ int main(void)
         LOG_ERR("Failed to initialize BLE management: %d", rc);
         return rc;
     }
-    LOG_WRN("After BLE init");
 #else
     LOG_WRN("BLE not enabled");
 #endif
 
-    LOG_WRN("Main park loop active");
 
-    // k_sleep(K_MSEC(500));
+#if IS_ENABLED(CONFIG_BATT_MGMT)
-    // LOG_INF("Playing test audio files...");
+    k_sleep(K_MSEC(100));
-    // audio_queue_play("/lfs/sys/update", false);
+    int32_t batt_mv;
-    // audio_queue_play("/lfs/sys/confirm", false);
+    int batt_rc = batt_mgmt_measure_vddh_mv(BATT_MGMT_OVERSAMPLING_16X, &batt_mv);
+    if (batt_rc == 0) {
+        LOG_INF("Battery after boot: %d mV", batt_mv);
+    } else {
+        LOG_WRN("Battery measurement after boot failed: %d", batt_rc);
+    }
+
+	k_sleep(K_SECONDS(1));
+	batt_mgmt_state_t batt_state = batt_mgmt_get_battery_state();
+	LOG_INF("Battery state after 1s: %s (%d)", battery_state_to_str(batt_state), batt_state);
+#endif
     for (;;) {
         int32_t rem_ms = k_sleep(K_FOREVER);
         LOG_WRN("main woke unexpectedly (remaining=%d ms)", rem_ms);