How do you subscribe multiple topics on nRF9160?

[Yusuke]

I want to subscribe two topics. How do you implement it?

static int subscribe(void)
{
	struct mqtt_topic subscribe_topic_1 = {
		.topic = {
			.utf8 = CONFIG_MQTT_SUB_TOPIC_1,
			.size = strlen(CONFIG_MQTT_SUB_TOPIC_1)
		},
		.qos = MQTT_QOS_1_AT_LEAST_ONCE
	};

	struct mqtt_topic subscribe_topic_2 = {
		.topic = {
			.utf8 = CONFIG_MQTT_SUB_TOPIC_2,
			.size = strlen(CONFIG_MQTT_SUB_TOPIC_2)
		},
		.qos = MQTT_QOS_1_AT_LEAST_ONCE
	};

	const struct mqtt_subscription_list subscription_list = {
		.list = &subscribe_topic, // TODO HOW DO YOU SET TWO TPICS?
		.list_count = 2,
		.message_id = 1234
	};

	printk("Subscribing to: %s len %u\n", CONFIG_MQTT_SUB_TOPIC,
		(unsigned int)strlen(CONFIG_MQTT_SUB_TOPIC));

	return mqtt_subscribe(&client, &subscription_list);
}

[Jan Tore Guggedal]

Hi,

To subscribe to multiple topics, you can do the following:

static int subscribe(void)
{
	struct mqtt_topic subscribe_topics[] = {
		{
		    .topic = {
			    .utf8 = CONFIG_MQTT_SUB_TOPIC_1,
			    .size = strlen(CONFIG_MQTT_SUB_TOPIC_1)
		    },
		    .qos = MQTT_QOS_1_AT_LEAST_ONCE
		},
        	{
		    .topic = {
			    .utf8 = CONFIG_MQTT_SUB_TOPIC_2,
			    .size = strlen(CONFIG_MQTT_SUB_TOPIC_2)
		    },
		    .qos = MQTT_QOS_1_AT_LEAST_ONCE
		}
	};

	const struct mqtt_subscription_list subscription_list = {
		.list = subscribe_topics,
		.list_count = ARRAY_SIZE(subscribe_topics),
		.message_id = 1234
	};

	printk("Subscribing to: %s len %u\n", CONFIG_MQTT_SUB_TOPIC,
		(unsigned int)strlen(CONFIG_MQTT_SUB_TOPIC));

	return mqtt_subscribe(&client, &subscription_list);
}

Best regards,

Jan Tore

[Yusuke]

GREAT!