ESP32 Forum

Posted: **Mon Mar 10, 2025 9:15 am**

I see in esp32-arduino that there's at least some callback providing dtr and rts lines (https://docs.espressif.com/projects/ard ... b_cdc.html ARDUINO_USB_CDC_LINE_STATE_EVENT)

in ESP-IDF, how can I read (in device mode) and write (in host mode) the (virtual) dtr and rts lines?

Posted: **Wed Mar 12, 2025 9:44 am**

You can use this to know when the state of DTR and RTS changes.
callback_line_state_changed
This is the same function as ARDUINO_USB_CDC_LINE_STATE_EVENT.

How to use:
https://github.com/nopnop2002/esp-idf-s ... ain.c#L172

I don't know of any functions that change the state of DTR and RTS.

Posted: **Wed Mar 12, 2025 4:33 pm**

USB client (tinyusb)
https://github.com/espressif/esp-idf/bl ... main.c#L66

USB host
https://github.com/espressif/esp-idf/bl ... ain.c#L173

ESP32 Forum

with USB CDC on ESP32-S3 and S2, how can I read and set DTR and RTS lines?

with USB CDC on ESP32-S3 and S2, how can I read and set DTR and RTS lines?

Re: with USB CDC on ESP32-S3 and S2, how can I read and set DTR and RTS lines?

Re: with USB CDC on ESP32-S3 and S2, how can I read and set DTR and RTS lines?