(See the README.md file in the upper level 'examples' directory for more information about examples.)
A USB device can provide multiple functions that are active simultaneously. Such multi-function devices are also known as composite devices. This example shows how to set up ESP chip to work as a USB Serial Device as well as MSC device (Storage media as SPI-Flash).
As a USB stack, a TinyUSB component is used.
## How to use example
### Hardware Required
Any ESP board that supports the USB-OTG peripheral.
### Pin Assignment
_Note:_ In case your board doesn't have micro-USB connector connected to USB-OTG peripheral, you may have to DIY a cable and connect **D+** and **D-** to the pins listed below.
See common pin assignments for USB Device examples from [upper level](../../README.md#common-pin-assignments).
Next, for Self-Powered Devices with VBUS monitoring, user must set ``self_powered`` to ``true`` and ``vbus_monitor_io`` to GPIO number (``VBUS_MONITORING_GPIO_NUM``) that will be used for VBUS monitoring.
### Build and Flash
Build the project and flash it to the board, then run monitor tool to view serial output:
```bash
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 (344) main_task: Calling app_main()
I (344) example_main: USB Composite initialization
W (354) TinyUSB: The device's configuration descriptor is not provided by user, using default.
W (364) TinyUSB: The device's string descriptor is not provided by user, using default.
W (374) TinyUSB: The device's device descriptor is not provided by user, using default.
I (384) tusb_desc:
┌─────────────────────────────────┐
│ USB Device Descriptor Summary │
├───────────────────┬─────────────┤
│bDeviceClass │ 239 │
├───────────────────┼─────────────┤
│bDeviceSubClass │ 2 │
├───────────────────┼─────────────┤
│bDeviceProtocol │ 1 │
├───────────────────┼─────────────┤
│bMaxPacketSize0 │ 64 │
├───────────────────┼─────────────┤
│idVendor │ 0x303a │
├───────────────────┼─────────────┤
│idProduct │ 0x4001 │
├───────────────────┼─────────────┤
│bcdDevice │ 0x100 │
├───────────────────┼─────────────┤
│iManufacturer │ 0x1 │
├───────────────────┼─────────────┤
│iProduct │ 0x2 │
├───────────────────┼─────────────┤
│iSerialNumber │ 0x3 │
├───────────────────┼─────────────┤
│bNumConfigurations │ 0x1 │
└───────────────────┴─────────────┘
I (544) TinyUSB: TinyUSB Driver installed
I (554) example_main: Initializing storage...
I (554) example_main: Initializing wear levelling
I (584) example_main: USB Composite initialization DONE
