esp-idf/examples/peripherals/usb/host/cdc/cdc_acm_host/README.md

Supported Targets	ESP32-S2	ESP32-S3

USB CDC-ACM Host Driver Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example shows how to use the CDC-ACM Host Driver to allow an ESP chip to communicate with a USB CDC-ACM device.

How to use example

Hardware Required

Two ESP boards that have USB-OTG supported. One will act as USB host and the other as USB device.
Connect USB_D+, USB_D-, GND and +5V signals of USB host to USB device.

Pin Assignment

See common pin assignments for USB Device examples from upper level.

Build and Flash

1. Build and flash tusb_serial_device example to USB device board.
2. Build this project and flash it to the USB host board, then run monitor tool to view serial output:

idf.py -p PORT flash monitor

(Replace PORT with the name of the serial port to use.)

(To exit the serial monitor, type Ctrl-].)

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

After the flashing you should see the output at idf monitor:

I (256) USB-CDC: USB Host installed
I (256) USB-CDC: Opening CDC ACM device 0x303A:0x4001
CDC Header Descriptor:
        bcdCDC: 1.20
CDC Call Descriptor:
        bmCapabilities: 0x00
        bDataInterface: 1
CDC ACM Descriptor:
        bmCapabilities: 0x02
CDC Union Descriptor:
        bControlInterface: 0
        bSubordinateInterface[0]: 1
I (1666) USB-CDC: Data received
I (1666) USB-CDC: 0x3ffc4c20   41 54 0d                                          |AT.|
I (2666) USB-CDC: Data received
I (2666) USB-CDC: 0x3ffc4c20   41 54 2b 47 53 4e 0d                              |AT+GSN.|
I (3666) USB-CDC: Setting up line coding
I (3666) USB-CDC: Line Get: Rate: 115200, Stop bits: 0, Parity: 0, Databits: 8
I (3666) USB-CDC: Line Set: Rate: 9600, Stop bits: 1, Parity: 1, Databits: 7
I (3666) USB-CDC: Line Get: Rate: 9600, Stop bits: 1, Parity: 1, Databits: 7
I (3676) Example finished successfully!
...