Stm32f1+bc20+mqtt+freertos system is connected to Alibaba cloud to transmit temperature and humidity and control LED lights

One 、 Material preparation
Prepare the following materials


Two 、 Device to connect
2.1、 Insert IOT network card
take BC20 Unplug the core board from the motherboard , Insert the card in the IOT card according to the instructions BC20 Core board . Plug in the IOT network card , Re BC20 Replace the core board with the main board

2.2、 Connect the temperature and humidity sensor
Find... On the motherboard JP2, take DHT11 The temperature and humidity sensor is connected , Pay attention to the positive and negative poles , Don't answer it backwards , After connection DHT11 The light of temperature and humidity sensor is on

2.3、 Access the emulator
Access the emulator , For downloading programs . The blue line is redundant

2.4、 Access to computer
Connect the board with the computer USB Serial cable connection , Switch on USB It's about , a main board LED5 Light up ,ST-LINK The emulator is also plugged into the computer

3、 ... and 、 Alibaba cloud Internet of things platform to create products 、 equipment
3.1、 Account registration 、 Log in
Alibaba cloud ：
https://cn.aliyun.com/

If you have an account number , Log in directly . If there is no account number , Then register according to the official prompt .
Log in after registration

Follow the prompts to enter the Internet of things platform interface



3.2、 Create products
In the Internet of things platform , There are products in equipment management 、 Equipment etc. , The product is equivalent to Xiaomi Bracelet , The device is similar to a bracelet A. Next, create a new product . In the Internet of things platform , Click on product , Create

Follow the prompts to fill in the relevant information

Product creation complete

3.3、 Create device
Follow the prompts to create the device

Fill in the information as prompted

The creation is complete

3.4、 Add product attributes
Follow the prompts to add product attributes


Add temperature attribute , Note that identifiers should be consistent ！！！

Add humidity attribute , Note that identifiers should be consistent ！！！

Add to complete

Click publish online

Four 、 Code changes 、 Program download 、 To configure
4.1、 To configure ST-Link Emulator
Open the code , Click Configure emulator






4.2、 Modify the code
Follow the instructions to get TopicPost

Follow the instructions to get Topic

Follow the instructions to get ProductKey、DeviceName、DeviceSecret

Follow the prompts to modify the code
Be careful ：Topic、TopicPost Medium ${deviceName} Need to replace with DeviceName！！！

4.3、 Download program


5、 ... and 、 View the data 、 Issue command to control relay
5.1、 View the uploaded temperature and humidity data
As can be seen from the figure, our temperature and humidity data have been uploaded to Alibaba cloud's Internet of things platform in real time

5.2、 Issue instructions to control LED The lamp
Follow the prompts to issue instructions

Input instruction ：OpenDevice, open LED The lamp

After sending , On the board LED The indicator lights up

Input instruction ：CloseDevice, close LED

After sending , On the board LED The indicator light goes out