distance calculator chart on esp8266
Required Library :--> ESP8266, Ultrasonic , Ultrasonic_Lib Tools :--> ESP8266FS IMPORTANT :--> esp8266wifi.h
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When programming the NODEMCU card with the Arduino IDE, you need to customize it and you must have selected the correct card.
Open Arduino IDE and go to files and click on the preference in the Arduino IDE.
Add the following link to the Additional Manager URLS section: "http://arduino.esp8266.com/stable/package_esp8266com_index.json" and press the OK button.
Then click Tools> Board Manager. Type "ESP8266" in the text box to search and install the ESP8266 software for Arduino IDE.
You will be successful when you try to program again by selecting the NodeMCU card after these operations.