How to make Arduino read data from USB?

Question

Arduino

There is a WiFi module but it is not asked. He was thrown aside. Now I need to somehow get the Arduino to connect to the computer via USB and read the data.
Example:
I run a web server on my computer and make a web interface to control Arduino (let's say write something on the display or work with a relay). The server (on node) receives the requests and sends them to the arduino. I can program the server and arduino, but how to transfer data from a computer to arduino via USB?

Answer 1

Found a solution Here
NodeJS and Arduino without other programs

Answer 2

The board ( for example, nano ) has a USB-UART converter (IC1, used for both firmware and data exchange). You program accordingly in UART (IC3) and "open" a virtual COM port on the PC (for example - / dev / ttyUSB0, which is organized over USB due to IC1).
Voila! There is a connection.