# Preface

Friends who have read my previous articles must know that I built a simple development environment for ESP8266, which can be developed through a wired serial port or a network link. I use MicroPython. The reason why I use it instead of Arduino is because I know how to A little Python hehehe.

For how to build it, please refer to the previous article "《Build a micropython development environment for ESP8266 from scratch》

Now we use it to link DHT22 to get real-time temperature and humidity!

# Physical connection

Firstly, connect the ESP8266 and DHT22, the wiring is as follows:

# debug

Connect the ESP8266 to the computer, use putty to connect, if you forget how to connect, you can click 【Here】 Review the steps.

Once connected, enter the following code in the command line interface:

import dht
from machine import Pin
sensor = dht.DHT22(Pin(4))#Set the physical interface
sensor.measure()#measure temperature and humidity
print("\nTemperature is %s degrees, Humidity is %s percent\n"%(sensor.temperature(),sensor.humidity()))

The correct output should look like the image below:

This means that the current temperature is 23.2° and the humidity is 66.6%. I have annotated the important parts in the code.

# Epilogue

This is just a simple demo, designed to simply obtain the data of DHT22, and I will use it to display the data in a browser or other methods later.

In fact, what I want most is to connect all kinds of sensors to Apple's home applications, but MicroPython wants to realize this function. I saw that it is very complicated, but Arduino is simple and clear.