MQTT Client on RB


This guide describes the testing method of mqtt client for the Rugged Board A5d2x.



  • Rugged Board A5d2x
  • ubuntu pc


  • Not Require


Step 1: Add the below additional packages in yocto and use compiled rootfs.
  • mosquitto
  • tcpdump
Step 2: Download the source from below link and cross compile it.
$ git clone
$ cd paho.mqtt.c/
$ git reset --hard 7e9b814bfb81d1edc32d8cef3594d5265ffb2395
→ Run the toolchain of rugged board a5d2x to cross compile the application source.
Step 3: Edit the publish and subscribe files of mqtt applications as below
$ vi src/samples/MQTTClient_publish.c +22
→ Here give the ip address of board as below and save the file.
#define ADDRESS "tcp://"
→ Same for subscribe file too
$ vi src/samples/MQTTClient_subscribe.c +22
→ Here give the ip address of board as below
#define ADDRESS "tcp://"
Step 4: Save and compile using below commands
$ make clean
$ make
Step 5: After compilation, copy the libraries from below path to usr/lib in the board
$ build/output/libpaho-mqtt3*
→ Copy the these two applications with name of "MQTTClient_subscribe", "MQTTClient_publish" from below path to "home/root" of the board.
$ build/output/samples/
Step 6: Edit the mosquitto configuration file as below in the board
$ vi /etc/mosquitto/mosquitto.conf
→ Add below lines in and save the file.
# Place your local configuration in /etc/mosquitto/conf.d/
# A full description of the configuration file is at
# /usr/share/doc/mosquitto/examples/mosquitto.conf.example
listener 1883
Note: here 1883 is port and is board ip address.
Step 7: Run the below command in the board.
$ mosquitto -c /etc/mosquitto/mosquitto.conf &
→ ssh to the board ip address as "ssh [email protected]" from your PC.
→ And run the below binary to get the data
→ Then run the below binary to sent the data in other terminal(do ssh to the board)

Below are the test logs for above commands:

Output logs of ./MQTTClient_subscribe:
root@rugged-board-a5d2x-sd1:~# ./MQTTClient_subscribe
Subscribing to topic MQTT Examples
for client ExampleClientSub using QoS1
Press Q<Enter> to quit
Message arrived
topic: MQTT Examples
message: Hello World!
Output logs for ./MQTTClient_publish:
root@rugged-board-a5d2x-sd1:~# ./MQTTClient_publish
Waiting for up to 10 seconds for publication of Hello World!
on topic MQTT Examples for client with ClientID: ExampleClientPub
Message with delivery token 1 delivered
Output logs of mosquitto -c /etc/mosquitto/mosquitto.conf command:
root@rugged-board-a5d2x-sd1:~# mosquitto -c /etc/mosquitto/mosquitto.conf
1325381603: mosquitto version 1.4.14 (build date 2020-11-04 14:08:01+0000) starting
1325381603: Config loaded from /etc/mosquitto/mosquitto.conf.
1325381603: Opening ipv4 listen socket on port 1883.
1325381610: New connection from on port 1883.
1325381610: New client connected from as ExampleClientPub (c1, k20).
1325381611: Client ExampleClientPub disconnected.