Mobile App, MQTT Client, IoT Exercise

 

MQTT Exercise with Mobile App, without Security

In the previous process, MQTT was tested using only a PC.

Here, we test by adding a mobile app to the mqtt client device while maintaining the previous test settings.

 

 

 

 

1. Test system configuration

♦ Run MQTT broker on PC.

♦ Set the first client to subscribe to the topic /momo, and the second client to subscribe to the topic /toto.

♦ The third client is executed to publish the message “Hi, MOMO” to the topic /momo.

♦ The last client is the app on the mobile phone, → first try to subscribe to the topic called /momo → then try to publish a message to the topic /momo.

 

 

 

 

 

 

 

 

2.  MQTT PC Test test procedure

 

Step1. Open a windows cmd window and check the IP address of the PC to be used as a broker.

any path> ipconfig

 

 

 

Step2. Run MQTT broker/server in windows cmd window.

~ mosquitto>mosquitto -v

 

 

 

 

Step3. Open a new windows cmd window and run the client subscribing to /momo.

~/mosquitto>mosquitto_sub -h 192.168.0.4 -t /momo

 

 

 

 

Step4. Open a new windows cmd window and run the client subscribing to /soso.

~/mosquitto>mosquitto_sub -h 192.168.0.4 -t /momo

 

 

 

 

 

Step5. Run the mobile app to run the client subscribing to /momo.

Install the MQTT client in Google Player and set it as shown on the right. You can use your favorite app.

 

 

 

 

Step6. Open a new windows cmd window and try to publish the message “Hi, MOMO” to the topic /momo.

~/mosquitto>mosquitto_pub -h 192.168.0.4 -t /momo -m “Hi, MOMO”

 

 

 

 

Step7. In the mobile client (App), try to publish the message “Hello, momo” to /soso.

 

 

 

 

 

 

3. MQTT PC Test Result

The final result screen of this test is shown in the figure below.

This time, because of the mobile app, the client subscribing to /soso finally gets the message.