“In today’s tutorial, we will use an ESP-01, which is the ESP8266 in configuration 01 (with only 2 GPIO), for temperature and humidity readings of the DHT22 sensor. I will show you an electrical schematic and the ESP programming part with an Arduino. The example is simple, easy to understand, and also comes with the PDF used in the video to aid in assembly.
In the design, we have then the ESP01, the source that converts 110 or 220 into 5 volts, a voltage regulator of 3v3, and the DHT22, which is the sensor. On the smartphone screen, you will have the local IP address in addition to the JavaScript code provided by the ESP. This screen will therefore receive the parameters of temperature and humidity and will print these values, which will be updated every five seconds. To do this, you wont need any apps on phones and tablets, and this applies for both the Android OS and IOS.”