Not able to connect to local mosquito broker instance

Libraries
1

I am trying demo (FreeRTOSv202012.00\FreeRTOS-Plus\Demo\coreMQTT_Windows_Simulator\MQTT_Plain_Text) on my windows PC.
I am able to connect with test.mosquito.org but not with local installed mosquito broker.
Getting timeout error (116) with freertos_connect().
What settings required to be done?

2

You need to edit mosquitto.conf to set the network interface and port number Mosquitto will listen on. Here is an exert from the file on my machine. Note I set a high port number because otherwise the firewall blocks the connection:

#bind the default listener to. If not
# given, the default listener will not be bound to a specific
# address and so will be accessible to all network interfaces.
# bind_address ip-address/host name
bind_address 192.168.0.28

# Port to use for the default listener.
# port 1883
port 50000

Then you need to set the same information in the demo_config.h file within the FreeRTOS project.

/**
 * @brief MQTT broker end point to connect to.
 *
 * @note If you would like to setup an MQTT broker for running this demo,
 * please see `mqtt_broker_setup.txt`.
 *
 * #define democonfigMQTT_BROKER_ENDPOINT				"192.168.0.28"
 */


/**
 * @brief The port to use for the demo.
 *
 * #define democonfigMQTT_BROKER_PORT					50000
 */
3

Note we are also working on some examples that use an MQTT agent to provide full multithreading within this repo: https://github.com/FreeRTOS/Lab-Project-coreMQTT-Agent

4

Thanks for the reply.
I tried the same but still getting errors.
Below is the log.

The interface that will be opened is set by “configNETWORK_INTERFACE_TO_USE”, which
should be defined in FreeRTOSConfig.h
Attempting to open interface number 7.
Successfully opened interface number 7.
0 348 [IP-task] vDHCPProcess: offer 192.168.0.105
vDHCPProcess: offer 192.168.0.105
1 668 [IP-task] [INFO] [MQTTDemo] [vApplicationIPNetworkEventHook:190] ---------STARTING DEMO---------

2 668 [IP-task] [INFO] [MQTTDemo] [vApplicationIPNetworkEventHook:199]

IP Address: 192.168.0.105

3 668 [IP-task] [INFO] [MQTTDemo] [vApplicationIPNetworkEventHook:202] Subnet Mask: 255.255.255.0

4 668 [IP-task] [INFO] [MQTTDemo] [vApplicationIPNetworkEventHook:205] Gateway Address: 192.168.0.1

5 668 [IP-task] [INFO] [MQTTDemo] [vApplicationIPNetworkEventHook:208] DNS Server Address: 192.168.0.1

6 668 [DemoTask] [INFO] [MQTTDemo] [prvConnectToServerWithBackoffRetries:514] Create a TCP connection to 192.168.0.107:56000.
7 5668 [DemoTask] [ERROR] [Sockets] [Sockets_Connect:102] Failed to connect to server: FreeRTOS_Connect failed: ReturnCode=-116, Hostname=192.168.0.107, Port=56000.
8 5668 [DemoTask] [ERROR] [Sockets] [Plaintext_FreeRTOS_Connect:93] Failed to connect to 192.168.0.107 with error -116.
9 5668 [DemoTask] [WARN] [MQTTDemo] [prvConnectToServerWithBackoffRetries:537] Connection to the broker failed. Retrying connection with backoff and jitter.

5

So the connection is timing out.

I know some people have problems connecting to echo servers that are running on the same machine as the FreeRTOS app - maybe this is the same issue (which I don’t have myself). Can you try running Mosquitto on a different computer on the same network?

6

Another tip is to try using a third party MQTT client to try the connection first to make sure that can connect successfully. I use https://mqttfx.jensd.de/