usbcdc_write/usbcdc_read/usbcdc_available ?

[vvb333007]

Hello everyone!

For UART we have uart_write_bytes(), uart_read_bytes()/...

Question#1:
Do we have something simple for USB-CDC?

I have found these:

Code: Select all

ssize_t esp_usb_console_write_buf(const char* buf, size_t size);
ssize_t esp_usb_console_flush(void);
ssize_t esp_usb_console_read_buf(char* buf, size_t buf_size);
bool esp_usb_console_read_available(void);
bool esp_usb_console_write_available(void);

in private headers, but comment there says do not use it from the user code.

Question#2:
Why it is not recommended to use these functions?


My problem is that I have code, which has command line interface. Depending on the configuration it should be deployed either on UART0 or on USB (hardware CDC). For the uart it is simple (uart_write_bytes), however, for the USB I can't find simple write/read/available functions.

Comment in the code above also says that users are advised to use VFS to access USB, but I am not sure how to do that plus, I am not sure if ESP-IDF is compiled with VFS support (I use Arduino framework which is shipped with ESP-IDF precompiled)

[nopnop2002]

How to use USB OTG.
https://github.com/espressif/esp-idf/tr ... sb_console

How to use USB CDC.
https://github.com/espressif/esp-idf/tr ... b/host/cdc

You need to understand the difference between USB OTG and USB CDC.
USB OTG acts as a device and USB CDC acts as a host.

Only ESP32S2/S3/P4 supports this feature.

The "cdcacm" VFS driver was available in ESP-IDF V4, but is likely gone in ESP-IDF V5.

I don’t use Arduino framework.