Simple cdc host example

Simple USB host CDC example which should works with any CDC-ACM device. Tested with arduino tinyusb device built using https://github.com/chegewara/EspTinyUSB library.

Example logs:

Before connecting device

Hello world USB host!
I (627) : USB host setup properly
I (627) : Port powered ON
Waiting for conenction

After connecting device

I (892) : HCD_PORT_EVENT_CONNECTION
I (892) : HCD_PORT_STATE_DISABLED
I (952) : USB device reset
I (952) : HCD_PORT_STATE_ENABLED
...
I (974) : address set: 1
I (978) : set current configuration: 1

Example reading device descriptors and strings

• device descriptor on EP0

  Device descriptor:
  Length: 18
  Descriptor type: 18
  USB version: 2.00
  Device class: 0xef (Miscellaneous)
  Device subclass: 0x02
  Device protocol: 0x01
  EP0 max packet size: 64
  VID: 0x303a
  PID: 0x0002
  Revision number: 1.00
  Manufacturer id: 1
  Product id: 2
  Serial id: 3
  Configurations num: 1

• configuration descriptor

  
  Config:
  Number of Interfaces: 2
  Attributes: 0xa0
  Max power: 500 mA

Interface: bInterfaceNumber: 0 bAlternateSetting: 0 bNumEndpoints: 1 bInterfaceClass: 0x02 (CDC) bInterfaceSubClass: 0x02 bInterfaceProtocol: 0x00

CS_Interface:

CS_Interface:

CS_Interface:

CS_Interface:

Endpoint: bEndpointAddress: 0x81 bmAttributes: 0x03 bDescriptorType: 5 wMaxPacketSize: 8 bInterval: 16 ms Creating transfer requests

Interface: bInterfaceNumber: 1 bAlternateSetting: 0 bNumEndpoints: 2 bInterfaceClass: 0x0a (CDC-data) bInterfaceSubClass: 0x00 bInterfaceProtocol: 0x00

Endpoint: bEndpointAddress: 0x02 bmAttributes: 0x02 bDescriptorType: 5 wMaxPacketSize: 64 bInterval: 0 ms Creating transfer requests

Endpoint: bEndpointAddress: 0x82 bmAttributes: 0x02 bDescriptorType: 5 wMaxPacketSize: 64 bInterval: 0 ms Creating transfer requests

- manufacturer, product and serial strings

strings: Espressif strings: ESP32S2 arduino device strings: 1234-5678

- set DTR/RTS lines and bitrate, stop bits, parity and data bits

I (7306) Set control line state: I (7311) Set line coding: Bitrate: 115200, stop bits: 0, parity: 0, bits: 5

### Testing
- after connecting we can start sending data from CDC ACM device to host and see received data in logs,
- when we send `?` from device then host should send back `test\n` to device

Have a nice play.