Chapter I use of DHT11 temperature and humidity sensor

Among the ten Bi design works , At least four devices will use temperature and humidity sensors , So this article first teaches you how to use DHT11 Temperature and humidity sensor . Enter... On Taobao “DHT11” You can find this sensor directly , The price is cheaper .

Here's the picture ,DHT11 The temperature and humidity sensor has four pins , But in practice, we only use three pins , They are connection 3.3V or 5V Of 1 Pin 、 Responsible for data communication 2 Pins and connections GND Of 4 Pin , and 3 Pin No. is named NC, It means empty pin , There's no practical use . Many students found three pins on Taobao DHT11 sensor , Those three pins are in the picture 1、2、4 Pin , So don't worry about whether the temperature and humidity sensor you buy is different from the temperature and humidity sensor introduced in this chapter .

          Let's talk about STM32F103C8T6 And DHT11 Communication code , Follow the official account at the bottom of the article , There is a code download link at the bottom of the corresponding tweet section of the official account , After downloading the materials , According to the wiring diagram in the data , DuPont line STM32F103C8T6 And DHT11 Connect the temperature and humidity sensors , Re pass Jlink or STlink Burn the code into STM32 Then you can .

         wendu[ ] and shidu[ ] These two arrays store DHT11 Temperature and humidity data transmitted by the sensor .

        delay_init( )  Initialization delay function , After executing this statement ,28 Yes delay_ms（1000） The delay effect will be accurate .

        14 Row sum 16 Line is only related to serial port printing , among NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2) Is to set interrupt priority grouping ,uart_init(9600) Responsible for initializing the serial port 1, The baud rate is 9600. Deleting these two lines of code will not affect STM32 Acquisition of temperature and humidity data .

        DHT11_INIT( )  DHT11 Initialization function , After initialization, temperature and humidity data can be collected .

        Read_DHT_Data(wendu, shidu)   Get the numerical function of temperature and humidity , After executing this statement ,DHT11 The detected temperature data is stored in wendu[ ], Humidity data is stored in

shidu[ ] in . among wendu[0] Stored is an integer of the temperature value ,wendu[1] Stored is the decimal of the temperature value ,shidu[0] Stored is an integer of humidity value ,shidu[1] The decimal of humidity value is stored .

        24 Row sum 26 Yes printf( ) It is a serial port printing function , As long as you don't delete 14 Row sum 16 Line code , Whole main Function code can realize every 1 Seconds to print temperature and humidity data .

         Since then, the code explanation has been completed , Students who want to know the specific implementation process of each function can download the code at the bottom of the article .

         When our design uses DHT11 Temperature and humidity sensor , Just know the function marked in red above , You can easily transplant the linked code into your own design code , In later chapters , I will show you .（ The premise is that the master of the design MCU choose STM32F103C8T6）

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