USB Driver ========== Overview -------- 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. If the board has no USB connector but has the pins, connect pins directly to the host (e.g. with do-it-yourself cable from any USB connection cable). For example, connect GPIO19/20 to D-/D+ respectively for an ESP32-S2 board: .. figure:: ../../../_static/usb-board-connection.png :align: center :alt: Connection of a board to a host ESP32-S2 :figclass: align-center Driver Structure ---------------- As the basis is used the TinyUSB stack. On top of it the driver implements: - Customization of USB descriptors - Serial device support - 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/`. .. list-table:: :widths: 35 65 :header-rows: 1 * - Code Example - Description * - :example:`peripherals/usb/tusb_console` - How to set up {IDF_TARGET_NAME} chip to get log output via Serial Device connection * - :example:`peripherals/usb/tusb_sample_descriptor` - How to set up {IDF_TARGET_NAME} chip to work as a Generic USB Device with a user-defined descriptor * - :example:`peripherals/usb/tusb_serial_device` - How to set up {IDF_TARGET_NAME} chip to work as a USB Serial Device API Reference ------------- .. include-build-file:: inc/tinyusb.inc .. include-build-file:: inc/tinyusb_types.inc .. include-build-file:: inc/tusb_cdc_acm.inc .. include-build-file:: inc/tusb_console.inc .. include-build-file:: inc/tusb_tasks.inc .. include-build-file:: inc/vfs_tinyusb.inc