The driver allows users to use {IDF_TARGET_NAME} chips to develop USB devices on top the TinyUSB stack. TinyUSB is integrating with ESP-IDF to provide USB features of the framework. Using this driver the chip works as a composite device supporting to represent several USB devices simultaneously. Currently, only the communications device class (CDC) type of the device with the ACM (Abstract Control Model) subclass is supported.
Features
--------
- Configuration of device and string USB descriptors
- USB Serial Device (CDC-ACM)
- Input and output through USB Serial Device
Hardware USB Connection
-----------------------
- Any board with the {IDF_TARGET_NAME} chip with USB connectors or with exposed USB's D+ and D- (DATA+/DATA-) pins.
- Redirecting of standard streams through the Serial device
- Encapsulated driver's task servicing the TinyuSB
Configuration
-------------
Via Menuconfig options you can specify:
- Several of descriptor's parameters (see: Descriptors Configuration bellow)
- USB Serial low-level Configuration
- The verbosity of the TinyUSB's log
- Disable the TinyUSB main task (for the custom implementation)
Descriptors Configuration
^^^^^^^^^^^^^^^^^^^^^^^^^
The driver's descriptors are provided by the :cpp:type:`tinyusb_config_t` structure's :cpp:member:`descriptor` and :cpp:member:`string_descriptor` members. Therefore, users should initialize :cpp:type:`tinyusb_config_t` to their desired descriptor before calling :cpp:func:`tinyusb_driver_install` to install driver.
However, the driver also provides a default descriptor. The driver can be installed with the default descriptor by setting the :cpp:member:`descriptor` and :cpp:member:`string_descriptor` members of :cpp:type:`tinyusb_config_t` to `NULL` before calling :cpp:func:`tinyusb_driver_install`. The driver's default descriptor is specified using Menuconfig, where the following fields should be configured:
- PID
- VID
- bcdDevice
- Manufacturer
- Product name
- Name of CDC device if it is On
- Serial number
If you want to use own descriptors with extended modification, you can define them during the driver installation process
Install Driver
--------------
To initialize the driver, users should call :cpp:func:`tinyusb_driver_install`. The driver's configuration is specified in a :cpp:type:`tinyusb_config_t` structure that is passed as an argument to :cpp:func:`tinyusb_driver_install`.
Note that the :cpp:type:`tinyusb_config_t` structure can be zero initialized (e.g. ``tinyusb_config_t tusb_cfg = { 0 }``) or partially (as shown below). For any member that is initialized to `0` or `NULL`, the driver will use its default configuration values for that member (see example below)
..code-block:: c
tinyusb_config_t partial_init = {
.descriptor = NULL; //Uses default descriptor specified in Menuconfig
.string_descriptor = NULL; //Uses default string specified in Menuconfig
.external_phy = false;
}
USB Serial Device (CDC-ACM)
---------------------------
If the CDC option is enabled in Menuconfig, the USB Serial Device could be initialized with :cpp:func:`tusb_cdc_acm_init` according to the settings from :cpp:type:`tinyusb_config_cdcacm_t` (see example below).
..code-block:: c
tinyusb_config_cdcacm_t amc_cfg = {
.usb_dev = TINYUSB_USBDEV_0,
.cdc_port = TINYUSB_CDC_ACM_0,
.rx_unread_buf_sz = 64,
.callback_rx = NULL,
.callback_rx_wanted_char = NULL,
.callback_line_state_changed = NULL,
.callback_line_coding_changed = NULL
};
tusb_cdc_acm_init(&amc_cfg);
To specify callbacks you can either set the pointer to your :cpp:type:`tusb_cdcacm_callback_t` function in the configuration structure or call :cpp:func:`tinyusb_cdcacm_register_callback` after initialization.
USB Serial Console
^^^^^^^^^^^^^^^^^^
The driver allows to redirect all standard application strings (stdin/out/err) to the USB Serial Device and return them to UART using :cpp:func:`esp_tusb_init_console`/:cpp:func:`esp_tusb_deinit_console` functions.
Application Examples
--------------------
The table below describes the code examples available in the directory :example:`peripherals/usb/`.
