src: modules: Use relative timestamps

simensrostad · simensrostad · commit 996585c5cd22 · 2025-12-22T17:57:15.000+01:00
Use relative timestamps captured at the time of measurement for
environmental and location data.

Signed-off-by: Simen S. Røstad &lt;simen.rostad@nordicsemi.no&gt;
diff --git a/app/src/modules/cloud/cloud.c b/app/src/modules/cloud/cloud.c
@@ -341,15 +341,23 @@ static void handle_network_data_message(const struct network_msg *msg)
 {
 	int err;
 	bool confirmable = IS_ENABLED(CONFIG_APP_CLOUD_CONFIRMABLE_MESSAGES);
+	int64_t timestamp_ms = NRF_CLOUD_NO_TIMESTAMP;
 
 	if (msg->type != NETWORK_QUALITY_SAMPLE_RESPONSE) {
 		return;
 	}
 
+	/* Convert uptime to unix time */
+	timestamp_ms = msg->uptime;
+	err = date_time_uptime_to_unix_time_ms(&timestamp_ms);
+	if (err) {
+		LOG_ERR("date_time_uptime_to_unix_time_ms, error: %d", err);
+	}
+
 	err = nrf_cloud_coap_sensor_send(CUSTOM_JSON_APPID_VAL_CONEVAL,
-					msg->conn_eval_params.energy_estimate,
-					NRF_CLOUD_NO_TIMESTAMP,
-					confirmable);
+				msg->conn_eval_params.energy_estimate,
+				timestamp_ms,
+				confirmable);
 	if (err) {
 		LOG_ERR("nrf_cloud_coap_sensor_send, error: %d", err);
 		send_request_failed();
@@ -358,9 +366,9 @@ static void handle_network_data_message(const struct network_msg *msg)
 	}
 
 	err = nrf_cloud_coap_sensor_send(NRF_CLOUD_JSON_APPID_VAL_RSRP,
-					msg->conn_eval_params.rsrp,
-					NRF_CLOUD_NO_TIMESTAMP,
-					confirmable);
+				msg->conn_eval_params.rsrp,
+				timestamp_ms,
+				confirmable);
 	if (err) {
 		LOG_ERR("nrf_cloud_coap_sensor_send, error: %d", err);
 		send_request_failed();
@@ -375,27 +383,27 @@ static int send_storage_data_to_cloud(const struct storage_data_item *item)
 	int64_t timestamp_ms = NRF_CLOUD_NO_TIMESTAMP;
 	const bool confirmable = IS_ENABLED(CONFIG_APP_CLOUD_CONFIRMABLE_MESSAGES);
 
-	/* Get current timestamp */
-	err = date_time_now(&timestamp_ms);
-	if (err) {
-		LOG_WRN("Failed to get current time, using no timestamp");
-		timestamp_ms = NRF_CLOUD_NO_TIMESTAMP;
-	}
-
 #if defined(CONFIG_APP_POWER)
 	if (item->type == STORAGE_TYPE_BATTERY) {
-		double battery_percentage = item->data.BATTERY;
+		const struct power_msg *power = &item->data.BATTERY;
+
+		/* Convert uptime to unix time */
+		timestamp_ms = power->uptime;
+		err = date_time_uptime_to_unix_time_ms(&timestamp_ms);
+		if (err) {
+			LOG_ERR("date_time_uptime_to_unix_time_ms, error: %d", err);
+		}
 
 		err = nrf_cloud_coap_sensor_send(CUSTOM_JSON_APPID_VAL_BATTERY,
-						 battery_percentage,
+						 power->percentage,
 						 timestamp_ms,
 						 confirmable);
 		if (err) {
 			LOG_ERR("Failed to send battery data to cloud, error: %d", err);
 			return err;
 		}
 
-		LOG_DBG("Battery data sent to cloud: %.1f%%", battery_percentage);
+		LOG_DBG("Battery data sent to cloud: %.1f%%", power->percentage);
 
 		/* Unused variable if no other sources compiled in */
 		(void)confirmable;
@@ -408,6 +416,13 @@ static int send_storage_data_to_cloud(const struct storage_data_item *item)
 	if (item->type == STORAGE_TYPE_ENVIRONMENTAL) {
 		const struct environmental_msg *env = &item->data.ENVIRONMENTAL;
 
+		/* Convert uptime to unix time */
+		timestamp_ms = env->uptime;
+		err = date_time_uptime_to_unix_time_ms(&timestamp_ms);
+		if (err) {
+			LOG_ERR("date_time_uptime_to_unix_time_ms, error: %d", err);
+		}
+
 		return cloud_environmental_send(env, timestamp_ms, confirmable);
 	}
 #endif /* CONFIG_APP_ENVIRONMENTAL */
@@ -432,8 +447,9 @@ static int send_storage_data_to_cloud(const struct storage_data_item *item)
 
 	LOG_WRN("Unknown storage data type: %d", item->type);
 
-	/* Unused variable if no data sources are enabled */
+	/* Unused variables if no data sources are enabled */
 	(void)confirmable;
+	(void)timestamp_ms;
 
 	return -ENOTSUP;
 }
diff --git a/app/src/modules/cloud/cloud_location.c b/app/src/modules/cloud/cloud_location.c
@@ -255,11 +255,20 @@ static void handle_agnss_request(const struct nrf_modem_gnss_agnss_data_frame *r
 
 #if defined(CONFIG_LOCATION_METHOD_GNSS)
 /* Handle GNSS location data from the location module */
-static void handle_gnss_location_data(const struct location_data *location_data)
+static void handle_gnss_location_data(const struct location_msg *location_msg)
 {
 	int err;
 	int64_t timestamp_ms = NRF_CLOUD_NO_TIMESTAMP;
 	bool confirmable = IS_ENABLED(CONFIG_APP_CLOUD_CONFIRMABLE_MESSAGES);
+	const struct location_data *location_data = &location_msg->gnss_data;
+
+	/* Convert uptime to unix time */
+	timestamp_ms = location_msg->uptime;
+	err = date_time_uptime_to_unix_time_ms(&timestamp_ms);
+	if (err) {
+		LOG_ERR("date_time_uptime_to_unix_time_ms, error: %d", err);
+	}
+
 	struct nrf_cloud_gnss_data gnss_data = {
 		.type = NRF_CLOUD_GNSS_TYPE_PVT,
 		.ts_ms = timestamp_ms,
@@ -275,16 +284,6 @@ static void handle_gnss_location_data(const struct location_data *location_data)
 		(double)location_data->longitude,
 		(double)location_data->accuracy);
 
-	/* Get current timestamp */
-	err = date_time_now(&timestamp_ms);
-	if (err) {
-		LOG_WRN("Failed to get current time");
-
-		timestamp_ms = NRF_CLOUD_NO_TIMESTAMP;
-	}
-
-	gnss_data.ts_ms = timestamp_ms;
-
 #if defined(CONFIG_LOCATION_DATA_DETAILS)
 #define CLOUD_GNSS_HEADING_ACC_LIMIT (float)60.0
 
@@ -333,7 +332,7 @@ void cloud_location_handle_message(const struct location_msg *msg)
 #if defined(CONFIG_LOCATION_METHOD_GNSS)
 	case LOCATION_GNSS_DATA:
 		LOG_DBG("GNSS location data received");
-		handle_gnss_location_data(&msg->gnss_data);
+		handle_gnss_location_data(msg);
 		break;
 #endif /* CONFIG_LOCATION_METHOD_GNSS */
 
diff --git a/app/src/modules/environmental/Kconfig.environmental b/app/src/modules/environmental/Kconfig.environmental
@@ -28,15 +28,6 @@ config APP_ENVIRONMENTAL_WATCHDOG_TIMEOUT_SECONDS
 	  A small difference between the two can mean more frequent watchdog feeds, which increases
 	  power consumption.
 
-config APP_ENVIRONMENTAL_TIMESTAMP
-	bool "Include timestamp in environmental message"
-	depends on DATE_TIME
-	default y
-	help
-	  Include a timestamp in the environmental message of ENVIRONMENTAL_SENSOR_SAMPLE_RESPONSE
-	  type.
-	  The timestamp is the current time in milliseconds since epoch.
-
 config APP_ENVIRONMENTAL_MSG_PROCESSING_TIMEOUT_SECONDS
 	int "Maximum message processing time"
 	default 3
diff --git a/app/src/modules/environmental/environmental.c b/app/src/modules/environmental/environmental.c
@@ -11,10 +11,6 @@
 #include <zephyr/task_wdt/task_wdt.h>
 #include <zephyr/smf.h>
 
-#if defined(CONFIG_APP_ENVIRONMENTAL_TIMESTAMP)
-#include <date_time.h>
-#endif
-
 #include "app_common.h"
 #include "environmental.h"
 
@@ -122,15 +118,9 @@ static void sample_sensors(const struct device *const bme680)
 		.temperature = sensor_value_to_double(&temp),
 		.pressure = sensor_value_to_double(&press),
 		.humidity = sensor_value_to_double(&humidity),
+		.uptime = k_uptime_get(),
 	};
 
-#if defined(CONFIG_APP_ENVIRONMENTAL_TIMESTAMP)
-	err = date_time_now(&msg.timestamp);
-	if (err) {
-		LOG_ERR("date_time_now() failed, error: %d, using 0", err);
-	}
-#endif /* CONFIG_APP_ENVIRONMENTAL_TIMESTAMP */
-
 	/* Log the environmental values and limit to 2 decimals */
 	LOG_DBG("Temperature: %.2f C, Pressure: %.2f Pa, Humidity: %.2f %%",
 		msg.temperature, msg.pressure, msg.humidity);
diff --git a/app/src/modules/environmental/environmental.h b/app/src/modules/environmental/environmental.h
@@ -48,8 +48,11 @@ struct environmental_msg {
 	/** Contains the current pressure in Pa. */
 	double pressure;
 
-	/** Timestamp of the sample in milliseconds since epoch. */
-	int64_t timestamp;
+	/** Uptime when the sample was taken in milliseconds.
+	 *  Use date_time_uptime_to_unix_time_ms() to convert to unix time before sending to cloud.
+	 *  Only valid for ENVIRONMENTAL_SENSOR_SAMPLE_RESPONSE events.
+	 */
+	int64_t uptime;
 };
 
 #define MSG_TO_ENVIRONMENTAL_MSG(_msg)	(*(const struct environmental_msg *)_msg)
diff --git a/app/src/modules/location/location.c b/app/src/modules/location/location.c
@@ -228,7 +228,8 @@ static void gnss_location_send(const struct location_data *location_data)
 	int err;
 	struct location_msg location_msg = {
 		.type = LOCATION_GNSS_DATA,
-		.gnss_data = *location_data
+		.gnss_data = *location_data,
+		.uptime = k_uptime_get()
 	};
 
 	err = zbus_chan_pub(&LOCATION_CHAN, &location_msg, K_SECONDS(1));
diff --git a/app/src/modules/location/location.h b/app/src/modules/location/location.h
@@ -183,6 +183,12 @@ struct location_msg {
 		 */
 		struct location_data gnss_data;
 	};
+
+	/** Uptime when the location was obtained in milliseconds.
+	 *  Use date_time_uptime_to_unix_time_ms() to convert to unix time before sending to cloud.
+	 *  Only valid for LOCATION_GNSS_DATA events.
+	 */
+	int64_t uptime;
 };
 
 #define MSG_TO_LOCATION_TYPE(_msg)	(((const struct location_msg *)_msg)->type)
diff --git a/app/src/modules/network/network.c b/app/src/modules/network/network.c
@@ -258,6 +258,7 @@ static void sample_network_quality(void)
 	int ret;
 	struct network_msg msg = {
 		.type = NETWORK_QUALITY_SAMPLE_RESPONSE,
+		.uptime = k_uptime_get()
 	};
 
 	ret = lte_lc_conn_eval_params_get(&msg.conn_eval_params);
diff --git a/app/src/modules/network/network.h b/app/src/modules/network/network.h
@@ -141,6 +141,12 @@ struct network_msg {
 		IF_ENABLED(CONFIG_LTE_LC_CONN_EVAL_MODULE,
 			   (struct lte_lc_conn_eval_params conn_eval_params));
 	};
+
+	/** Uptime when the sample was taken in milliseconds.
+	 *  Use date_time_uptime_to_unix_time_ms() to convert to unix time before sending to cloud.
+	 *  Only valid for NETWORK_QUALITY_SAMPLE_RESPONSE events.
+	 */
+	int64_t uptime;
 };
 
 #define MSG_TO_NETWORK_MSG(_msg)	(*(const struct network_msg *)_msg)
diff --git a/app/src/modules/power/Kconfig.power b/app/src/modules/power/Kconfig.power
@@ -52,15 +52,6 @@ config APP_POWER_MSG_PROCESSING_TIMEOUT_SECONDS
 	  Maximum time allowed for processing a single message in the module's state machine.
 	  The value must be smaller than CONFIG_APP_POWER_WATCHDOG_TIMEOUT_SECONDS.
 
-config APP_POWER_TIMESTAMP
-	bool "Include timestamp in power message"
-	depends on DATE_TIME
-	default y
-	help
-	  Include a timestamp in the power message of POWER_BATTERY_PERCENTAGE_SAMPLE_RESPONSE
-	  type.
-	  The timestamp is the current time in milliseconds since epoch.
-
 module = APP_POWER
 module-str = Power
 source "subsys/logging/Kconfig.template.log_config"
diff --git a/app/src/modules/power/power.c b/app/src/modules/power/power.c
@@ -14,7 +14,6 @@
 #include <zephyr/drivers/mfd/npm13xx.h>
 #include <zephyr/sys/util.h>
 #include <nrf_fuel_gauge.h>
-#include <date_time.h>
 #include <math.h>
 #include <zephyr/task_wdt/task_wdt.h>
 #include <zephyr/smf.h>
@@ -400,15 +399,9 @@ static void sample(int64_t *ref_time)
 		.percentage = (double)roundf(state_of_charge),
 		.charging = charging,
 		.voltage = (double)voltage,
+		.uptime = k_uptime_get()
 	};
 
-#if defined(CONFIG_APP_POWER_TIMESTAMP)
-	err = date_time_now(&msg.timestamp);
-	if (err) {
-		LOG_ERR("date_time_now() failed, error: %d, using 0", err);
-	}
-#endif /* CONFIG_APP_POWER_TIMESTAMP */
-
 	err = zbus_chan_pub(&POWER_CHAN, &msg, K_NO_WAIT);
 	if (err) {
 		LOG_ERR("zbus_chan_pub, error: %d", err);
diff --git a/app/src/modules/power/power.h b/app/src/modules/power/power.h
@@ -41,14 +41,17 @@ struct power_msg {
 	/** Contains the current charge of the battery in percentage. */
 	double percentage;
 
-	/** Timestamp of the sample in milliseconds since epoch. */
-	int64_t timestamp;
-
 	/** True if the battery is charging, false otherwise. */
 	bool charging;
 
 	/** Voltage in volts. */
 	double voltage;
+
+	/** Uptime when the sample was taken in milliseconds.
+	 *  Use date_time_uptime_to_unix_time_ms() to convert to unix time before sending to cloud.
+	 *  Only valid for POWER_BATTERY_PERCENTAGE_SAMPLE_RESPONSE events.
+	 */
+	int64_t uptime;
 };
 
 #define MSG_TO_POWER_MSG(_msg)	(*(const struct power_msg *)_msg)
diff --git a/app/src/modules/storage/storage_data_types.c b/app/src/modules/storage/storage_data_types.c
@@ -51,9 +51,9 @@ bool battery_check(const struct power_msg *msg)
 	return msg->type == POWER_BATTERY_PERCENTAGE_SAMPLE_RESPONSE;
 }
 
-void battery_extract(const struct power_msg *msg, double *data)
+void battery_extract(const struct power_msg *msg, struct power_msg *data)
 {
-	*data = msg->percentage;
+	*data = *msg;
 }
 #endif /* CONFIG_APP_POWER */
 
diff --git a/app/src/modules/storage/storage_data_types.h b/app/src/modules/storage/storage_data_types.h
@@ -62,7 +62,7 @@
  */
 #define DATA_SOURCE_LIST(X)									\
 	IF_ENABLED(CONFIG_APP_POWER,								\
-		   (X(BATTERY, POWER_CHAN, struct power_msg, double,				\
+		   (X(BATTERY, POWER_CHAN, struct power_msg, struct power_msg,			\
 		      battery_check, battery_extract)))						\
 	IF_ENABLED(CONFIG_APP_ENVIRONMENTAL,							\
 		   (X(ENVIRONMENTAL, ENVIRONMENTAL_CHAN,					\
diff --git a/docs/common/architecture.md b/docs/common/architecture.md
@@ -287,3 +287,11 @@ smf_set_state(SMF_CTX(state_object), &states[NEW_STATE]);
 
 A transition to another state has to be the last thing happening in a state handler. This is to ensure correct order of execution of parent state handlers.
 SMF automatically handles the execution of exit and entry functions for all states along the path to the new state.
+
+## Timestamp Pattern for Sampled Data
+
+Modules that sample data (environmental, power, location, network) follow a consistent timestamp pattern to ensure accurate time information for cloud transmission:
+
+- **At sampling time**: Modules capture the system uptime using `k_uptime_get()` and store it in an `int64_t uptime` field within the message structure. This represents the relative time in milliseconds when the sample was taken.
+
+- **Before cloud transmission**: The cloud module converts the uptime to Unix timestamp using `date_time_uptime_to_unix_time_ms()` immediately before sending data to the cloud. This ensures that the timestamp reflects the actual sampling time, not the transmission time.
diff --git a/tests/module/cloud/src/cloud_module_test.c b/tests/module/cloud/src/cloud_module_test.c
diff --git a/tests/module/environmental/CMakeLists.txt b/tests/module/environmental/CMakeLists.txt
diff --git a/tests/module/environmental/src/environmental_module_test.c b/tests/module/environmental/src/environmental_module_test.c
diff --git a/tests/module/power/CMakeLists.txt b/tests/module/power/CMakeLists.txt
diff --git a/tests/module/power/src/power_module_test.c b/tests/module/power/src/power_module_test.c
diff --git a/tests/module/storage/src/storage_module_test.c b/tests/module/storage/src/storage_module_test.c
