What is esp32usb

esp32usb is an ESP-IDF component that provides an alternative for the ESP-IDF TinyUSB component. This code uses https://github.com/hathach/tinyusb rather than https://github.com/espressif/tinyusb.

esp32usb is primarily tested with the ESP32-S2 but should work with the ESP32-S3 once generally available.

NOTE: esp32usb requires ESP-IDF v4.3 or later to work correctly.

How to use

In your project, add this as a submodule to your components/ directory.

git submodule add https://github.com/atanisoft/esp32usb.git
git submodule update --recursive --init -- esp32usb

The library can be configured via idf.py menuconfig under TinyUSB (esp32usb).

Integrating esp32usb with your project

In the app_main() method you should have code similar to the following:

void app_main() {
  init_usb_subsystem();
  configure_usb_descriptor_str(USB_DESC_MANUFACTURER, "esp32usb");
  configure_usb_descriptor_str(USB_DESC_PRODUCT, "esp32usb Device");
  configure_usb_descriptor_str(USB_DESC_SERIAL_NUMBER, "1234567890");
  start_usb_task();
  .... rest of application code
}

Integrating a virtual disk drive

If you are configuring a virtual disk you will need to configure it prior to calling start_usb_task():

static const char * const readme_txt =
  "This is esp32usb's MassStorage Class demo.\r\n\r\n"
  "If you find any bugs or get any questions, feel free to file an\r\n"
  "issue at github.com/atanisoft/esp32usb"

void app_main() {
  init_usb_subsystem();
  configure_usb_descriptor_str(USB_DESC_MANUFACTURER, "esp32usb");
  configure_usb_descriptor_str(USB_DESC_PRODUCT, "esp32usb Device");
  configure_usb_descriptor_str(USB_DESC_SERIAL_NUMBER, "1234567890");
  configure_virtual_disk("esp32usb", 0x0100);
  add_readonly_file_to_virtual_disk("readme.txt", readme_txt, strlen(readme_txt));
  add_partition_to_virtual_disk("spiffs", "spiffs.bin");
  add_firmware_to_virtual_disk();
  start_usb_task();

Virtual Disk limitations

1. The virtual disk support is currently limited to around 4MiB in size but may be configurable in the future.
2. Adding the firmware to the virtual disk is currently limited to showing only two OTA partitions (current and previous/next). If more than two OTA partitions are in use it is recommended to use add_partition_to_virtual_disk instead of add_firmware_to_virtual_disk so more images can be displayed.