Problem -116 error using mqtt protocal to connect EMQX broker server(GCP) in nRF9151 board

[Junyoung Jeon]

Hi,

I'm trying to connect to the EMQX(what I made on GCP) using mqtt protocal. I'm using the sample code that nordic provides in lesson. Based on the Exercise4 code which is l4_el_sol.

I successfully connected with a test server which is mqtt.nordicsemi.academy. So I changed hostname to EMQX host IP. And it doesn't work. I just changed the client->username, password

Fullscreen prj.conf setting.txt Download

# Logging
CONFIG_LOG=y
 
# Button and LED support
CONFIG_DK_LIBRARY=y
 
# Newlib
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y
# Networking
CONFIG_NETWORKING=y
CONFIG_NET_NATIVE=n
CONFIG_NET_SOCKETS_OFFLOAD=y
CONFIG_NET_SOCKETS=y
CONFIG_POSIX_API=y
 
# Memory
CONFIG_MAIN_STACK_SIZE=4096
CONFIG_HEAP_MEM_POOL_SIZE=2048
 
# Modem library
CONFIG_NRF_MODEM_LIB=y
 
# LTE link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT=y
 
# MQTT
# STEP 2.1 - Enable and configure the MQTT library
CONFIG_MQTT_LIB=y
CONFIG_MQTT_CLEAN_SESSION=y
 
# Application
# STEP 2.2 - Configure the broker name, TCP port, topic names, and message
CONFIG_MQTT_PUB_TOPIC="zephyr/test"
CONFIG_MQTT_SUB_TOPIC="devacademy/subscribe/topic"
CONFIG_MQTT_BROKER_HOSTNAME="34.46.65.84"
CONFIG_MQTT_BROKER_PORT=1883
 
 
 
#i2c configuration
CONFIG_I2C=y            # i2c function add
CONFIG_I2C_NRFX=y
 
CONFIG_NRFX_TWIM0=n
CONFIG_NRFX_TWIM1=n
CONFIG_NRFX_TWIM2=y
CONFIG_NRFX_TWIM3=n
 
CONFIG_PRINTK=y      
CONFIG_CONSOLE=y          
CONFIG_UART_CONSOLE=y
CONFIG_SERIAL=y          
 
 
 
CONFIG_ASSERT=y
CONFIG_I2C_LOG_LEVEL_DBG=y
CONFIG_LOG_MODE_IMMEDIATE=y
 
 
CONFIG_CBPRINTF_FP_SUPPORT=y   # float %f
CONFIG_MQTT_KEEPALIVE=120
 
CONFIG_MQTT_CLIENT_ID="JunyoungJeon"
CONFIG_MQTT_MESSAGE_BUFFER_SIZE=1024
 
CONFIG_NET_IPV4=y

Fullscreen 4721.mainc.txt Download

#include <stdio.h>
#include <ncs_version.h>
#include <zephyr/kernel.h>
#include <zephyr/net/socket.h>
 
#include <zephyr/logging/log.h>
#include <modem/nrf_modem_lib.h>
#include <modem/lte_lc.h>
/* Include the header file for the MQTT Library*/
#include <zephyr/net/mqtt.h>
 
#include "mqtt_connection.h"
 
/* I2C Headers */
#include <zephyr/sys/printk.h>
#include <zephyr/drivers/i2c.h>
 
 
#define SEN66_NODE DT_NODELABEL(sen66)
#define Measure 100
#define REMEASURE 30
#define STARTING_TIME 60
#define WATING_TIME 100
#define Exucution_Time 1500
 
 
 
 
/* I2C Function */
 
int read_measurement(const struct i2c_dt_spec *dev, uint8_t *buf, size_t len)
{
    int ret;
    uint8_t cmd_read[] = {0x03, 0x00};
 
    ret = i2c_write(dev->bus, cmd_read, sizeof(cmd_read), dev->addr);
    if (ret != 0) {
        printk("[SEN] Failed to send read command: %d\r\n", ret);
        return ret;
    }
 
    k_sleep(K_SECONDS(2));  // 센서가 데이터 준비할 시간
 
    ret = i2c_read(dev->bus, buf, len, dev->addr);
    if (ret != 0) {
        printk("[SEN] Failed to read measurement: %d\r\n", ret);
        return ret;
    }
 
    k_sleep(K_SECONDS(2));  // 처리 여유 시간 (필요 없다면 줄일 수 있음)
     
    return 0;  
}
 
 
uint16_t read_u16(uint8_t msb, uint8_t lsb) {
    return ((uint16_t)msb << 8) | lsb;
}
 
int16_t read_s16(uint8_t msb, uint8_t lsb) {
    return (int16_t)(((uint16_t)msb << 8) | lsb);  // - value possible
}
 
 
 
/* THE MQTT CONNECTION FOUNCTION */
static struct mqtt_client client;
 
/* File descriptor */
static struct pollfd fds;
 
static K_SEM_DEFINE(lte_connected, 0, 1);
 
LOG_MODULE_REGISTER(DRI, LOG_LEVEL_INF);
 
static void lte_handler(const struct lte_lc_evt *const evt)
{
     switch (evt->type) {
     case LTE_LC_EVT_NW_REG_STATUS:
        if ((evt->nw_reg_status != LTE_LC_NW_REG_REGISTERED_HOME) &&
            (evt->nw_reg_status != LTE_LC_NW_REG_REGISTERED_ROAMING)) {
            break;
        }
        printk("Network registration status: %s",
                evt->nw_reg_status == LTE_LC_NW_REG_REGISTERED_HOME ?
                "Connected - home network" : "Connected - roaming");
        k_sem_give(&lte_connected);
        break;
    // case LTE_LC_EVT_RRC_UPDATE:
    //   static enum lte_lc_rrc_mode prev_rrc_mode = -1;
 
    //     if (prev_rrc_mode != evt->rrc_mode) {
    //     printk("[RRC] Mode changed: %s \r\n", evt->rrc_mode == LTE_LC_RRC_MODE_CONNECTED ? "Connected" : "Idle");
    //     prev_rrc_mode = evt->rrc_mode;
    // }
    // break;
     default:
             break;
     }
}
 
static int modem_configure(void)
{
    int err;
 
    printk("Initializing modem library");
    err = nrf_modem_lib_init();
    if (err) {
        LOG_ERR("Failed to initialize the modem library, error: %d \r\n", err);
        return err;
    }
   
    printk("Connecting to LTE network\r\n");
    err = lte_lc_connect_async(lte_handler);
    if (err) {
        LOG_ERR("Error in lte_lc_connect_async, error: %d", err);
        return err;
    }
 
    k_sem_take(&lte_connected, K_FOREVER);
    printk("Connected to LTE network\r\n");
 
    return 0;
}
 
int publish_sensor_data(float pm1, float pm25, float pm4, float pm10,
                        float rh, float temp, float voc, float nox, float co2)
{
    char payload[128];
    int len = snprintf(payload, sizeof(payload),
        "{\"pm1\":%.2f,\"pm25\":%.2f,\"pm4\":%.2f,\"pm10\":%.2f,"
        "\"rh\":%.2f,\"temp\":%.2f,\"voc\":%.2f,\"nox\":%.2f,\"co2\":%.2f}",
        pm1, pm25, pm4, pm10,
        rh, temp, voc, nox, co2);
 
    return data_publish(&client,
                        MQTT_QOS_1_AT_LEAST_ONCE,
                        (const uint8_t *)payload,
                        len);
}
 
static void maintain_mqtt(void)
{
    // 소켓에 들어온 데이터(응답)가 있는지 확인
    int rc = poll(&fds, 1, 0);
    if (rc < 0) {
        LOG_ERR("poll 에러: %d", errno);
        return;
    }
    // 응답이 있으면 가져와서 처리
    if (rc > 0) {
        mqtt_input(&client);
    }
    // PINGREQ 보내고 내부 재전송 등 유지 작업 수행
    rc = mqtt_live(&client);
    if (rc && rc != -EAGAIN) {
        LOG_ERR("mqtt_live 에러: %d", rc);
    }
}
 
 
 
/* MAIN CODE START POINT */
 
void main(void)
{
    int err;
    int ret;
    float pm1_array[5];
    float pm25_array[5];
    float pm4_array[5];
    float pm10_array[5];
    float Humidity_array[5];
    float Temp_array[5];
    float VOC__array_Index[5];
    float NOx__array_Index[5];
    uint8_t co2_array[5];
    uint8_t data_buf[30];
    float sum = 0.0;
    uint32_t connect_attempt = 0;
 
 
    printk("[SEN] Sensor will be started \r\n");
 
    k_sleep(K_MSEC(WATING_TIME));
 
    const struct i2c_dt_spec sen66 = I2C_DT_SPEC_GET(SEN66_NODE);
 
    if (!device_is_ready(sen66.bus)) {
    LOG_ERR("[SEN] I2C bus %s is not ready!\r\n",sen66.bus->name);
   
    } else {
    printk("[SEN] I2C bus %s is ready \r\n", sen66.bus->name);
    }
 
    uint8_t cmd_start[] = {0x00, 0x21};
    ret = i2c_write_dt(&sen66, cmd_start, sizeof(cmd_start));
    if (ret == 0) {
        printk("[SEN] I2C Measurement is starting \r\n");
    } else {
        printk("[SEN] I2C MEASUREMENT IS FAILED : %d \r\n", ret);
       
    }
 
    k_sleep(K_MSEC(STARTING_TIME));
 
 
 
    //--------------------------------------------------------------------------//
 
 
    err = modem_configure();
    if (err) {
        LOG_ERR("Failed to configure the modem");
       
    }
 
    err = client_init(&client);
    if (err) {
        LOG_ERR("Failed to initialize MQTT client: %d", err);
       
    }
 
do_connect:
    if (connect_attempt++ > 0) {
        LOG_INF("Reconnecting in %d seconds...",
            CONFIG_MQTT_RECONNECT_DELAY_S);
        k_sleep(K_SECONDS(CONFIG_MQTT_RECONNECT_DELAY_S));
    }
 
    err = mqtt_connect(&client);
    if (err) {
        LOG_ERR("Error in mqtt_connect: %d", err);
        goto do_connect;
    }
 
    err = fds_init(&client,&fds);
    if (err) {
        LOG_ERR("Error in fds_init: %d", err);
    }
 
  int i;
   
 
 
 
  K_SEM_DEFINE(mqtt_connected, 0, 1);
 
void mqtt_evt_handler(struct mqtt_client *const c, const struct mqtt_evt *evt)
{
    switch (evt->type) {
    case MQTT_EVT_CONNACK:
        if (evt->result != 0) {
            LOG_ERR("MQTT connect failed: %d", evt->result);
            break;
        }
        LOG_INF("MQTT connected successfully");
        k_sem_give(&mqtt_connected); // 연결 성공 시 세마포어 give
        break;
 
    case MQTT_EVT_DISCONNECT:
        LOG_INF("MQTT disconnected: %d", evt->result);
        break;
 
    default:
        break;
    }
}
 
 
 
 
 
 
 
   
 
while (1) {
    sum=0.0;
 
    for ( i = 0; i <5; i++){
   
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    uint16_t pm1_raw = read_u16(data_buf[0], data_buf[1]);
    float pm1 = pm1_raw / 10.0f;
    pm1_array[i] = pm1;
    sum += pm1;
    printk("[SEN] pm1_array[%d]= %.2f ug/m3 \r\n", i , pm1_array[i] );
    k_sleep(K_MSEC(REMEASURE));
    maintain_mqtt();
 
 }
    float avg_pm1 = sum / 5.0f;
    printk("[SEN] sum %.2f \n\r",sum);
    printk("\r\n");
    printk(" -- PM25_Array Values -- \r\n");
    sum = 0.0f;
 
 
    for ( i = 0; i <5; i++){
    maintain_mqtt();
     
     ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
     uint16_t pm25_raw = read_u16(data_buf[3], data_buf[4]);
    float pm25 = pm25_raw / 10.0f;
    pm25_array[i] = pm25;
    sum += pm25;
    printk("[SEN] pm25_array[%d]= %.2f ug/m3 \r\n", i , pm25 );
    k_sleep(K_MSEC(REMEASURE));
    maintain_mqtt();
}
   
    float avg_pm25 = sum /5.0f;
    printk("[SEN] sum %.2f",sum);
   
    printk("\r\n");
    printk(" -- PM4_Array Values -- \r\n");
    sum = 0.0f;
for ( i = 0; i <5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    uint16_t pm4_raw = read_u16(data_buf[6], data_buf[7]);
    float pm4 = pm4_raw / 10.0f;
    pm4_array[i] = pm4;
    sum += pm4;
    printk("[SEN] pm4_array[%d]= %.2f ug/m3 \r\n", i , pm4 );
    k_sleep(K_MSEC(REMEASURE));
   maintain_mqtt();
 
}
   
    float avg_pm4 = sum /5.0f;
    printk("[SEN] sum %.2f",sum);
 
    printk("\r\n");
    printk(" -- PM10_Array Values -- \r\n");
    sum = 0.0f;
for ( i = 0; i <5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    uint16_t pm10_raw = read_u16(data_buf[9], data_buf[10]);
    float pm10 = pm10_raw / 10.0f;
    pm10_array[i] = pm10;
    sum += pm10;
    printk("[SEN] pm10_array[%d]= %.2f ug/m3 \r\n", i , pm10 );
    k_sleep(K_MSEC(REMEASURE));
    maintain_mqtt();
}
 
    float avg_pm10 = sum /5.0f;
    printk("[SEN] sum %.2f",sum);
   
    printk("\r\n");
    printk(" -- Humidity_Array Values -- \r\n");
    sum = 0.0f;
for(i=0; i<5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    int16_t Humidity_raw = read_s16(data_buf[12], data_buf[13]);
    float Humidity = Humidity_raw / 100.0f;
    Humidity_array[i] = Humidity;
    sum += Humidity;
    printk("[SEN] Humidity_array[%d]= %.2f ug/m3 \r\n", i ,Humidity  );
    k_sleep(K_MSEC(REMEASURE));
    maintain_mqtt();
}
 
    float avg_Humidity = sum /5.0f;
    printk("[SEN] sum %.2f",sum);
   
    printk("\r\n");
    printk(" -- Temp_Array Values -- \r\n");
    sum = 0.0f;
for(i=0; i<5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    int16_t Temp_raw = read_s16(data_buf[15], data_buf[16]);
    float Temp = Temp_raw  / 200.0f;
    Temp_array[i] = Temp;
    sum += Temp;
    printk("[SEN] Temp_array[%d]= %.2f T[C] \r\n", i , Temp );
    k_sleep(K_MSEC(REMEASURE));
    maintain_mqtt();
    }
 
    float avg_Temp = sum /5.0f;
    printk("[SEN] sum %.2f",sum);
   
    printk("\r\n");
    printk(" -- VOC_Array Values -- \r\n");
    sum = 0.0f;
for(i=0; i<5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    int16_t VOC_Index_raw = read_u16(data_buf[18], data_buf[19]);
    float VOC_Index = VOC_Index_raw  / 10.0f;
    VOC__array_Index[i] = VOC_Index;
    sum += VOC_Index;
    printk("[SEN] VOC_array[%d]= %.2f ug/m3 \r\n", i , VOC_Index  );
    k_sleep(K_MSEC(REMEASURE));
   maintain_mqtt();
}
    float avg_VOC_Index = sum /5.0f;
    printk("[SEN] sum %.2f",sum);
 
    printk("\r\n");
    printk(" -- Nox_Array Values -- \r\n");
    sum = 0.0f;    
for(i=0; i<5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    int16_t NOx_Index_raw = read_u16(data_buf[21], data_buf[22]);
    float NOx_Index = NOx_Index_raw  / 10.0f;
    NOx__array_Index[i] = NOx_Index;
    sum +=NOx_Index;
    printk("[SEN] NOx_array[%d]= %.2f ug/m3 \r\n", i , NOx_Index );
    k_sleep(K_MSEC(REMEASURE));
   maintain_mqtt();
}
    float avg_NOx_Index = sum / 5.0f;
    printk("[SEN] sum %.2f",sum);
 
    printk("\r\n");
    printk(" -- co2 values -- \r\n");
    sum = 0.0f;
for(i=0; i<5; i++){
    maintain_mqtt();
    ret = read_measurement(&sen66, data_buf, sizeof(data_buf));
 
    uint16_t co2 = read_u16(data_buf[24], data_buf[25]);
    co2_array[i] =  co2;
    sum += co2;
    printk("[SEN] co2_array[%d]= %u ppm \r\n", i , co2  );
    k_sleep(K_MSEC(REMEASURE));
   
    maintain_mqtt();
}
 
    uint16_t avg_co2 = sum / 5.0f;
    printk("[SEN] sum %.2f",sum);
    printk("\r\n");
    printk(" -- Average values -- \r\n");
 
    k_sleep(K_SECONDS(5));
 
     // 5. Print values
    printk("[SEN] PM1.0     : %.2f ug/m3\r\n",avg_pm1);
    printk("[SEN] PM2.5     : %.2f ug/m3\r\n",avg_pm25);
    printk("[SEN] PM4.0     : %.2f ug/m3\r\n",avg_pm4);
    printk("[SEN] PM10.0    : %.2f ug/m3\r\n",avg_pm10);
    printk("[SEN] RH [%%]   : %.2f ug/m3  \n",avg_Humidity);
    printk("[SEN] T[C]      : %.2f T[C]\r\n" ,avg_Temp);
    printk("[SEN] VOC Index : %.2f ppb\r\n",avg_VOC_Index);
    printk("[SEN] NOx Index : %.2f ppb\r\n",avg_NOx_Index );
    printk("[SEN] CO2       : %u   ppm\r\n",avg_co2);  
 
    printk("\r\n");
    printk(" -- Measurements are done -- \r\n");
    printk("\r\n");
   
 
    maintain_mqtt();
 
 
        // MQTT Sending
    err = publish_sensor_data(avg_pm1,avg_pm25,avg_pm4,avg_pm10,avg_Humidity,avg_Temp,avg_VOC_Index,avg_NOx_Index,avg_co2);
    if (err) printk("MQTT sending is failed: %d\n", err);
    else printk("MQTT Sending is success\n");
 
 
       
    maintain_mqtt();
 
   
    }
 
    printk("Disconnecting MQTT client");
 
    err = mqtt_disconnect(&client, NULL);
    if (err) {
        LOG_ERR("Could not disconnect MQTT client: %d", err);
    }
    goto do_connect;
 
    k_sleep(K_SECONDS(60));
}

if you can find what problem is, please let me know. 

-ps connection.c and connection.h is exactly same as a l4_le_sol sample file

[Øyvind]

Hello, 

So I changed hostname to EMQX host IP.

Are you able to access this IP from your computer? I.e. can you use Mosquitto to send message from your computer to this MQTT broker?

Kind regards,
Øyvind

[Junyoung Jeon]

Hello,

Thank you for reply. Yes I can send the datas from my computer to "mqtt.nordicsemi.academy" which is the address Nordic provides. Should I try using Mosquitto? and do you know why it says -12 or -116? I changed a liittle bit in broker_init() now it says -12 error

Best regards,

Jeon

[Øyvind]

Junyoung Jeon said:

Yes I can send the datas from my computer to "mqtt.nordicsemi.academy"

If this works, then the issue sounds to be with the EMQX host IP, and not an issue with the nRF9151

Junyoung Jeon said:

Should I try using Mosquitto?

The reason for why I suggest this is to verify that you are able to connect to the EMQX host IP and if the issue is on the broker side or on the nRF9151 side. 

Junyoung Jeon said:

do you know why it says -12 or -116? I changed a liittle bit in broker_init() now it says -12 error

These error codes are found in e.g. nrfxlib/nrf_modem/include/nrf_errno.h.

#define NRF_ETIMEDOUT 116 /**< Connection timed out */

#define NRF_ENOMEM 12 /**< Not enough space */

Not enough space could indicate that the EMQX broker needs certificates that are larger than 2k, part of the limitation of the device:

*** Limitations
***************
- TLS and DTLS
    - Secure socket buffer size is 2kB.
    - Maximum length of DTLS datagram is 1kB.
    - One TLS handshake at a time is supported.
    - Concurrent secure connections
        - Maximum server certificate chain size has a limit of 4kB.
        - Two active connections are supported when serialized DTLS connection exists.
        - Two active connections are supported when any client certificate size is over 1kB.
        - Two active connections are supported when GNSS acquisition is active.
        - Three active connections are supported when client certificate sizes are 1kB or less.
        - Four serialized DTLS connections are supported.
    - Server certificate expiry time is not verified.
    - pkcs#8 is not supported.
    - Maximum number of supported credentials is 32. The actual amount depends on the size of
      credentials as the memory area reserved for credentials may be a limiting factor as well.
    - TLS is not supported when the socket is configured in TCP server mode.
- IP fragmentation and reassembly are not supported.
- It is recommended to free the modem resources by closing unused network sockets and by undefining
  unused PDN connections with AT+CGDCONT.
- Maximum number of raw sockets is 4.
- User plane data is supported in Cat M1 mode only.
- Non-IP Data Delivery (NIDD) feature is verified only for NB-IoT. NIDD for LTE-M is not supported.
- The number of ownership keys is restricted to one. Multiple instances are not allowed.

Perhaps the MQTT sample would be a better starting point for more advanced MQTT connections.

Kind regards,
Øyvind