app: Remove support for nRF Cloud MQTT

Use more lightweight CoAP protocol instead of MQTT.

Signed-off-by: Juha Ylinen <juha.ylinen@nordicsemi.no>

Author: juhaylinen

app/Kconfig

@@ -253,7 +253,16 @@ config SM_NRF_CLOUD
 config SM_NRF_CLOUD_LOCATION
 	bool "nRF Cloud Location support"
 	depends on SM_NRF_CLOUD
-	select NRF_CLOUD_LOCATION if NRF_CLOUD_MQTT
+	help
+	  Enable the nRF Cloud Location service for cloud-assisted geolocation.
+	  Supports A-GNSS, P-GPS, and Wi-Fi positioning:
+
+	  - A-GNSS: Reduces GNSS time-to-first-fix by downloading assistance data from nRF Cloud.
+	  - P-GPS: Enables predicted GPS ephemerides for offline or intermittent connectivity scenarios.
+	  - Wi-Fi: Uses Wi-Fi access point scanning for positioning without GNSS.
+
+	  A-GNSS and P-GPS data are sourced from the modem's GNSS subsystem; Wi-Fi data from the Wi-Fi scanner.
+	  A-GNSS and P-GPS can be enabled independently at compile time using NRF_CLOUD_AGNSS and NRF_CLOUD_PGPS.
 
 config SM_MQTTC
 	bool "MQTT client support"

app/overlay-nrf_cloud-coap.conf

@@ -92,7 +92,8 @@ CONFIG_NVS=y
 # nRF Cloud
 CONFIG_SM_NRF_CLOUD_LOCATION=y
 CONFIG_NRF_CLOUD=y
-CONFIG_NRF_CLOUD_MQTT=y
+CONFIG_NRF_CLOUD_COAP=y
+CONFIG_NRF_CLOUD_COAP_DOWNLOADS=n
 CONFIG_NRF_CLOUD_FOTA=n
 CONFIG_NRF_CLOUD_AGNSS=y
 CONFIG_NRF_CLOUD_AGNSS_FILTERED=n
@@ -105,6 +106,12 @@ CONFIG_DATE_TIME=y
 CONFIG_MODEM_INFO=y
 CONFIG_MODEM_INFO_ADD_DATE_TIME=n
 
+# CoAP client settings
+CONFIG_COAP_CLIENT_BLOCK_SIZE=1024
+CONFIG_COAP_CLIENT_THREAD_PRIORITY=0
+CONFIG_COAP_EXTENDED_OPTIONS_LEN_VALUE=96
+CONFIG_COAP_CLIENT_STACK_SIZE=2048
+
 # UUID and JWT
 CONFIG_MODEM_JWT=y
 

app/prj.conf

@@ -61,11 +61,9 @@ static struct k_work agnss_req_work;
 #endif
 #if defined(CONFIG_NRF_CLOUD_PGPS)
 static struct k_work pgps_req_work;
-#if defined(CONFIG_NRF_CLOUD_COAP)
 static struct k_work pgps_coap_req_work;
 static struct gps_pgps_request pgps_coap_request;
 #endif
-#endif
 
 #endif /* CONFIG_SM_NRF_CLOUD */
 
@@ -320,31 +318,17 @@ static void agnss_requestor(struct k_work *)
 {
 	int err;
 	struct nrf_modem_gnss_agnss_data_frame req;
+	static char agnss_rest_data_buf[NRF_CLOUD_AGNSS_MAX_DATA_SIZE];
+	struct nrf_cloud_rest_agnss_request request = {
+		NRF_CLOUD_REST_AGNSS_REQ_CUSTOM,
+		&req,
+	};
 
 	err = read_agnss_req(&req);
 	if (err) {
 		LOG_ERR("Failed to read A-GNSS request (%d).", err);
 		return;
 	}
-#if defined(CONFIG_NRF_CLOUD_MQTT)
-	err = nrf_cloud_agnss_request(&req);
-	if (err) {
-		LOG_ERR("Failed to request A-GNSS data (%d).", err);
-	} else {
-		LOG_INF("A-GNSS data requested.");
-		/* When A-GNSS data is received it gets injected in the background by
-		 * nrf_cloud_agnss_process() without notification. In the case where
-		 * CONFIG_NRF_CLOUD_PGPS=y, nrf_cloud_pgps_inject() (called on PGPS_EVT_AVAILABLE)
-		 * plays a role as A-GNSS expects P-GPS to process some of the data.
-		 */
-	}
-#endif
-#if defined(CONFIG_NRF_CLOUD_COAP)
-	static char agnss_rest_data_buf[NRF_CLOUD_AGNSS_MAX_DATA_SIZE];
-	struct nrf_cloud_rest_agnss_request request = {
-		NRF_CLOUD_REST_AGNSS_REQ_CUSTOM,
-		&req,
-	};
 
 	struct nrf_cloud_rest_agnss_result result = {agnss_rest_data_buf,
 						     sizeof(agnss_rest_data_buf), 0};
@@ -369,7 +353,6 @@ static void agnss_requestor(struct k_work *)
 		return;
 	}
 	LOG_INF("A-GNSS data received via CoAP.");
-#endif
 }
 #endif /* CONFIG_NRF_CLOUD_AGNSS */
 
@@ -387,7 +370,6 @@ static void pgps_requestor(struct k_work *)
 	}
 }
 
-#if defined(CONFIG_NRF_CLOUD_COAP)
 static void pgps_coap_requestor(struct k_work *)
 {
 	int err;
@@ -428,7 +410,6 @@ static void pgps_coap_requestor(struct k_work *)
 
 	LOG_INF("P-GPS predictions requested");
 }
-#endif
 
 static void pgps_event_handler(struct nrf_cloud_pgps_event *event)
 {
@@ -481,10 +462,8 @@ static void pgps_event_handler(struct nrf_cloud_pgps_event *event)
 		break;
 	case PGPS_EVT_REQUEST:
 		LOG_INF("PGPS_EVT_REQUEST");
-#if defined(CONFIG_NRF_CLOUD_COAP)
 		memcpy(&pgps_coap_request, event->request, sizeof(pgps_coap_request));
 		k_work_submit_to_queue(&sm_work_q, &pgps_coap_req_work);
-#endif
 		break;
 	}
 }
@@ -540,24 +519,11 @@ static int do_cloud_send_obj(struct nrf_cloud_obj *const obj)
 {
 	int err;
 
-#if defined(CONFIG_NRF_CLOUD_MQTT)
-	struct nrf_cloud_tx_data msg = {
-		.obj = obj,
-		.topic_type = NRF_CLOUD_TOPIC_MESSAGE,
-		.qos = MQTT_QOS_0_AT_MOST_ONCE
-	};
-
-	err = nrf_cloud_send(&msg);
-	if (err) {
-		LOG_ERR("nrf_cloud_send failed, error: %d", err);
-	}
-#endif
-#if defined(CONFIG_NRF_CLOUD_COAP)
 	err = nrf_cloud_coap_obj_send(obj, false);
 	if (err) {
 		LOG_ERR("nrf_cloud_send failed, error: %d", err);
 	}
-#endif
+
 	(void)nrf_cloud_obj_free(obj);
 
 	return err;
@@ -567,12 +533,27 @@ static void send_location(struct nrf_modem_gnss_pvt_data_frame * const pvt_data)
 {
 	static int64_t last_ts_ms = NRF_CLOUD_NO_TIMESTAMP;
 	int err;
+
+	/* Map modem PVT data to nRF Cloud PVT structure */
+	struct nrf_cloud_gnss_pvt pvt = {
+		.lat        = pvt_data->latitude,
+		.lon        = pvt_data->longitude,
+		.accuracy   = pvt_data->accuracy,
+		.alt        = pvt_data->altitude,
+		.has_alt    = 1,
+		.speed      = pvt_data->speed,
+		.has_speed  = 1,
+		.heading    = pvt_data->heading,
+		.has_heading = 1,
+	};
+
 	struct nrf_cloud_gnss_data gnss = {
 		.ts_ms = NRF_CLOUD_NO_TIMESTAMP,
-		.type = NRF_CLOUD_GNSS_TYPE_MODEM_PVT,
-		.mdm_pvt = pvt_data
+		.type = NRF_CLOUD_GNSS_TYPE_PVT,
+		.pvt = pvt,
 	};
-	NRF_CLOUD_OBJ_JSON_DEFINE(msg_obj);
+
+	NRF_CLOUD_OBJ_COAP_CBOR_DEFINE(msg_obj);
 	/* On failure, NRF_CLOUD_NO_TIMESTAMP is used and the timestamp is omitted */
 	(void)date_time_now(&gnss.ts_ms);
 
@@ -903,9 +884,7 @@ static int sm_at_gnss_init(void)
 #endif
 #if defined(CONFIG_NRF_CLOUD_PGPS)
 	k_work_init(&pgps_req_work, pgps_requestor);
-#if defined(CONFIG_NRF_CLOUD_COAP)
 	k_work_init(&pgps_coap_req_work, pgps_coap_requestor);
-#endif
 #endif /* CONFIG_NRF_CLOUD_PGPS */
 #endif /* CONFIG_SM_NRF_CLOUD */
 	k_work_init(&gnss_fix_send_work, gnss_fix_sender);