# USB Host CDC-ACM Class Driver This directory contains an implementation of a USB CDC-ACM Host Class Driver that is implemented on top of the [USB Host Library]( ## Supported Devices The CDC-ACM Host driver supports the following types of CDC devices: 1. CDC-ACM devices 2. CDC-like vendor specific devices (usually found on USB to UART bridge devices) ### CDC-ACM Devices The CDC-ACM Class driver supports CDC-ACM devices that meet the following requirements: - The device class code must be set to the CDC class `0x02` or implement Interface Association Descriptor (IAD) - The CDC-ACM must contain the following interfaces: - A Communication Class Interface containing a management element (EP0) and may also contain a notification element (an interrupt endpoint). The driver will check this interface for CDC Functional Descriptors. - A Data Class Interface with two BULK endpoints (IN and OUT). Other transfer types are not supported by the driver ### CDC-Like Vendor Specific Devices The CDC-ACM Class driver supports CDC-like devices that meet the following requirements: - The device class code must be set to the vendor specific class code `0xFF` - The device needs to provide and interface containing the following endpoints: - (Mandatory) Two Bulk endpoints (IN and OUT) for data - (Optional) An interrupt endpoint (IN) for the notification element For CDC-like devices, users are responsible for ensuring that they only call APIs (e.g., `cdc_acm_host_send_break()`) that are supported by the target device. ## Usage The following steps outline the typical API call pattern of the CDC-ACM Class Driver 1. Install the USB Host Library via `usb_host_install()` 2. Install the CDC-ACM driver via `cdc_acm_host_install()` 3. Call `cdc_acm_host_open()`/`cdc_acm_host_open_vendor_specific()` to open a target CDC-ACM/CDC-like device. These functions will block until the target device is connected 4. To transmit data, call `cdc_acm_host_data_tx_blocking()` 5. When data is received, the driver will automatically run the receive data callback 6. An opened device can be closed via `cdc_acm_host_close()` 7. The CDC-ACM driver can be uninstalled via `cdc_acm_host_uninstall()` ## Examples - For an example with a CDC-ACM device, refer to [cdc_acm_host](../../cdc_acm_host) - For an example with a CDC-like device, refer to [cdc_acm_host_bg96](../../cdc_acm_bg96)


License: Apache-2.0

To add this component to your project, run: add-dependency "espressif/usb_host_cdc_acm^1.0.3"

or download archive


  • ESP-IDF >=4.4
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    espressif/usb_host_cdc_acm version: 1.0.3 |