【Jihai APM32F407 Tiny Board】rt-thread stdudio Play with mqtt (10)

damiaa

【Jihai APM32F407 Tiny Board】rt-thread stdudio Play with mqtt (10) [Copy link]

 

【Jihai APM32F407 Tiny Board】rt-thread stdudio Play with mqtt (10)

[Jihai APM32F407 Tiny Board] Unboxing Review: Installation Environment and Lighting

[Jihai APM32F407 Tiny Board] Ethernet running example

[Jihai APM32F407 Tiny Board] Run a serial port example USART_Polling

[Jihai APM32F407 Tiny Board] Run a serial port example USART_Interrupt

[Jihai APM32F407 Tiny Board] Play with FreeRTOS

【Jihai APM32F407 Tiny Board】Start rt-thread

[Jihai APM32F407 Tiny Board] Play with FreeRTOS two message queues, keyboard and LED

[Jihai APM32F407 Tiny Board] rt-thread studio uses button and LED driver package

APM32F407 Tiny Board】RT-thread stdudio adc usage (9)

I recently played with the APM32F407 Tiny board and found that rt-thread studio is pretty good. After a few days of exploration, I found that I could play with mqtt .

1. Create a new chip-based project

The serial port uses version V1, otherwise an error will occur

2. Save, build, and download, and a hellworld project will appear.

3. Configure eth

Enable lwip and network interface devices as follows:

Use static IP as follows:

Add the definition BSP_USE_ETH PHY_USING_LAN8720A

to board.h as shown below

Write an empty phy_reset() function, because the reset leg is directly connected to the reset, and the CPU io reset is not used.

Remove main.c LOG_D("Hello RT-Thread!");

4, Save, Build, Download, Test: There is a problem, timeout, the computer can ping it.

Found that the computer firewall was not turned on:

That’s it, the network is connected:

5. Add the mqtt component. Here, select pahomqtt, which is used by many people.

Configure it:

6. Save and build, and find several problems: modify them and let it compile.

7. Build, download, test: it works, MQTT is running.

Here I use my own local mqtt broker. Remember to make sure the IP address is in the same network segment. Ping it before the experiment. Make sure you do not make mistakes with the broker IP address, username, password, and topic.

Thank you for watching.

caizhiwei

The host is awesome, mqtt is really a good thing

damiaa

caizhiwei posted on 2023-6-23 22:40 The OP is awesome, MQTT is indeed a good thing

Thanks for the encouragement!

freebsder

Boss, which qos setting is better for client and server?

damiaa

freebsder posted on 2023-6-24 22:36 Boss, which qos setting is better for the client and server?

It depends on the situation. If qos0 is used, it will be faster, but it is not guaranteed to be delivered accurately every time. For example, if you check the temperature, it will be done every few seconds. If it is not delivered, you can check it next time.

If it must be delivered every time without error, use qos1 or qos2.

According to my experience, qos0 is also relatively reliable. It is rare that it cannot be delivered (it is rare to encounter).

MQTT defines three QoS levels:

QoS 0, at most once delivery.
QoS 1, at least once delivery.
QoS 2, only once delivery.
Among them, using QoS 0 may lose messages, using QoS 1 can ensure that messages are received, but messages may be duplicated, and using QoS 2 can ensure that messages are neither lost nor duplicated. QoS levels from low to high not only mean the improvement of message reliability, but also the improvement of transmission complexity.

damiaa

freebsder posted on 2023-6-24 22:36 Big Mi, which qos setting is better for the client and server?

There are some good articles on csdn https://blog.csdn.net/emqx_broker/article/details/128659357