Design of intelligent weighing system based on Huawei cloud IOT (STM32) [II] there is information at the end

3.5 Topic subscription and Publishing

  adopt MQTT Client software simulation report test ：

View the console page , The data has been uploaded successfully .

3.6 Application side development

In order to display equipment data more conveniently , Interact with the device , We also need to develop a supporting host computer , The official provides the application side development API Interface 、SDK Interface , For convenience and versatility , I'm using API Interface to complete data interaction , The upper computer software adopts QT Development .

Help document address : https://support.huaweicloud.com/api-iothub/iot_06_v5_0034.html

The device attribute is the sensor status data information uploaded by the device , The application side provides API Interface , It can actively send request instructions to the device end ; After receiving the instruction, the device needs to report the data according to the agreed data format ; therefore , To realize the data interaction between the application layer and the device side , It needs the cooperation between the application layer and the device end to complete .

When using interfaces , It's best to use Huawei's own debugging interface to test .https://apiexplorer.developer.huaweicloud.com/apiexplorer/doc?product=IoTDA&api=ListProperties

The upper computer software adopts Qt framework design ,Qt It's a cross platform C++ GUI application framework .Qt It's a 1991 Year by year Qt Company Cross platform development C++ GUI application development framework . It can develop GUI Program , It can also be used to develop non GUI Program , For example, console tools and servers . Simply speaking ,QT It can easily help you make software with interface , It doesn't even require you to put a lot of energy .

QT Official website :https://www.qt.io/

4. STM32 Device side development

4.1 Program download

4.2 Schematic diagram

4.3 Hardware wiring

 

4.4 MQTT Connection code

MQTT The protocol connects Huawei cloud IOT Source project : https://download.csdn.net/download/xiaolong1126626497/81993720

 

 

 4.5 ESP8266 Code

 

 

 

 

 

 

 

 

 【 Learning exchange group 611386401】

【 Network disk free information package , Need to collect by yourself 】：

Embedded Internet of things 22 individual STM32 project 、 Competition works ,【 Huaqing vision issued the information package 】http://makerschool.mikecrm.com/f4wjYBB