modules: sensor: add configurable UTC timestamps to sensor data

Add CONFIG_SENSOR_MODULE_TIMESTAMP option to conditionally include UTC epoch
timestamps in sensor messages using date_time_now() instead of k_uptime_get().
Update controller logging to display human-readable timestamp format.

Refs: #21

Signed-off-by: Natalia Pluta <pluta.natalia.m@gmail.com>

Author: nmpluta

app/src/modules/controller/controller_module.c

@@ -359,7 +359,10 @@ static void log_sensor_data(const struct sensor_msg *msg)
 	LOG_INF("SEN0466: CO: %d ppm, Temp: %d.%06d C", msg->co.val1, msg->temperature_sen0466.val1,
 		msg->temperature_sen0466.val2);
 
-	LOG_INF("Sensor data timestamp: %lld ms", msg->timestamp);
+#if defined(CONFIG_SENSOR_MODULE_TIMESTAMP)
+	/* Log timestamp if enabled */
+	LOG_INF("Sensor data timestamp: %lld seconds since epoch (UTC)", msg->timestamp);
+#endif
 }
 
 /* Helper function to set state and keep current_state field in sync */

app/src/modules/sensor/Kconfig.sensor

@@ -44,6 +44,15 @@ config SENSOR_MODULE_MAX_RETRIES
 	help
 	  Maximum number of recovery attempts before giving up.
 
+config SENSOR_MODULE_TIMESTAMP
+	bool "Include timestamps in sensor data"
+	depends on DATE_TIME
+	default y
+	help
+	  Enable inclusion of timestamps in sensor messages sent via the sensor_chan ZBUS channel.
+	  The timestamp format is UTC, which is seconds since the epoch (January 1, 1970, 00:00:00 UTC),
+	  as provided by date_time_now().
+
 # Sensor-specific warmup configurations
 config SENSOR_MODULE_WARMUP_ENABLE
 	bool "Enable sensor warmup periods"

app/src/modules/sensor/sensor_module.c

@@ -9,6 +9,10 @@
 #include <zephyr/logging/log.h>
 #include <zephyr/smf.h>
 
+#if defined(CONFIG_SENSOR_MODULE_TIMESTAMP)
+#include <date_time.h>
+#endif
+
 LOG_MODULE_REGISTER(sensor_module, CONFIG_SENSOR_MODULE_LOG_LEVEL);
 
 /* Macro to validate sensor type enum values */
@@ -311,8 +315,15 @@ static void sensor_state_reading_run(void *obj)
 
 	/* Initialize response */
 	ctx->current_data.type = SENSOR_SAMPLE_RESPONSE;
-	ctx->current_data.timestamp = k_uptime_get();
-	ctx->last_read_time = ctx->current_data.timestamp;
+	ctx->last_read_time = k_uptime_get();
+#if defined(CONFIG_SENSOR_MODULE_TIMESTAMP)
+	ret = date_time_now(&ctx->current_data.timestamp);
+	if (ret < 0) {
+		LOG_ERR("Sensor SM: Failed to get current timestamp (%d)", ret);
+		LOG_WRN("Sensor SM: Setting timestamp to 0");
+		ctx->current_data.timestamp = 0;
+	}
+#endif
 
 	int successful_reads = 0;
 

app/src/modules/sensor/sensor_module.h

@@ -69,8 +69,10 @@ struct sensor_msg {
 	struct sensor_value co;
 	struct sensor_value temperature_sen0466;
 
+#if defined(CONFIG_SENSOR_MODULE_TIMESTAMP)
 	/* Timestamp - only valid for SENSOR_SAMPLE_RESPONSE */
 	int64_t timestamp;
+#endif
 };
 
 /* ZBUS channel declaration */