MQTT on 54L15

Hi all,

Has anyone implemented an MQTT client on an 54L15 before? I have been searching the web and I have not seen a sample program or anyone talking about MQTT with 54L15 only. I would appreciate any sample programs, it doesn't need to be complicated, I just want to verify that we can indeed implement the callback functions and its functionalities on 54L15. Thanks.

0 Allan-led 1 hour ago

Here is the code that I have attempted to create as a simple sample program, but I receive connect error: -12.

Here is my main.c:

#include <zephyr/kernel.h>
#include <zephyr/net/mqtt.h>
#include <zephyr/net/socket.h>
#include <stdio.h>

#define MQTT_BROKER_HOSTNAME "192.168.3.153"
#define MQTT_BROKER_PORT 1883
#define MQTT_CLIENT_ID "nrf54l15_subscriber"
#define MQTT_TOPIC_SUBSCRIBE "test/54L15"

static struct mqtt_client client;
static struct sockaddr_storage broker;

/* MQTT event handler */
void mqtt_evt_handler(struct mqtt_client *const client,
                     const struct mqtt_evt *evt)
{
    switch (evt->type) {
    case MQTT_EVT_CONNACK:
        if (evt->result != 0) {
            printk("Connection failed: %d\n", evt->result);
            return;
        }
        
        printk("Connected to broker\n");
        
        /* Subscribe to topic */
        struct mqtt_topic subscribe_topic = {
            .topic.utf8 = MQTT_TOPIC_SUBSCRIBE,
            .topic.size = strlen(MQTT_TOPIC_SUBSCRIBE)
        };
        
        const struct mqtt_subscription_list sub_list = {
            .list = &subscribe_topic,
            .list_count = 1,
            .message_id = 1
        };
        
        mqtt_subscribe(client, &sub_list);
        break;
        
    case MQTT_EVT_PUBLISH:
        /* Handle incoming messages */
        printk("Received: %.*s\n",
               evt->param.publish.message.payload.len,
               evt->param.publish.message.payload.data);
        break;
        
    case MQTT_EVT_DISCONNECT:
        printk("Disconnected from broker\n");
        break;

    default: 
        break;
    }
    
}

void connect_to_broker(void)
{
    int err;
    
    /* Initialize client */
    mqtt_client_init(&client);
    
    /* Set callback */
    client.evt_cb = mqtt_evt_handler;
    client.client_id.utf8 = MQTT_CLIENT_ID;
    client.client_id.size = strlen(MQTT_CLIENT_ID);
    
    /* Configure broker address */
    struct sockaddr_in *broker4 = (struct sockaddr_in *)&broker;
    broker4->sin_family = AF_INET;
    broker4->sin_port = htons(MQTT_BROKER_PORT);
    inet_pton(AF_INET, MQTT_BROKER_HOSTNAME, &broker4->sin_addr.s_addr);
    
    /* Configure transport */
    client.transport.type = MQTT_TRANSPORT_NON_SECURE;
    client.broker = (struct sockaddr *)&broker;
    
    printk("Client parameters: \n");
        printk("  Client ID: %s\n", client.client_id.utf8);
        printk("  Broker: %s:%d\n", MQTT_BROKER_HOSTNAME, MQTT_BROKER_PORT);
        printk("  Topic: %s\n", MQTT_TOPIC_SUBSCRIBE);
        printk("  Transport: %s\n", client.transport.type == MQTT_TRANSPORT_NON_SECURE ? "Non-secure" : "Secure");
        


    /* Connect to broker */
    err = mqtt_connect(&client);
    if (err != 0) {
        printk("Connect error: %d\n", err);
    }
}

int main(void)
{
    printk("Starting MQTT subscriber\n");
    connect_to_broker();
    
    while (1) {
        k_sleep(K_SECONDS(1));
    }
}

Here is my prj.conf:

CONFIG_NETWORKING=y
CONFIG_MQTT_LIB=y
CONFIG_MQTT_LIB_TLS=n
CONFIG_NET_SOCKETS=y
CONFIG_NET_SOCKETS_POSIX_NAMES=y
CONFIG_NET_IPV6=y
CONFIG_NET_TCP=y
CONFIG_NET_UDP=y
CONFIG_NET_DHCPV6=n
CONFIG_NET_MGMT=y
CONFIG_NET_MGMT_EVENT=y
CONFIG_LOG=y


CONFIG_SHELL=y
CONFIG_OPENTHREAD_SHELL=y
CONFIG_SHELL_ARGC_MAX=26
CONFIG_SHELL_CMD_BUFF_SIZE=416
CONFIG_OPENTHREAD_NORDIC_LIBRARY_MASTER=y
CONFIG_NET_L2_OPENTHREAD=y
CONFIG_SETTINGS_ZMS=y
CONFIG_ZMS=y
CONFIG_NVS=n
CONFIG_FLASH=y
CONFIG_FLASH_MAP=y
CONFIG_SPI_NOR=n 


CONFIG_MAIN_STACK_SIZE=6144
CONFIG_SHELL_STACK_SIZE=5120