EPS32-C3 USB serial not writing

[krcewm]

Hello,

I'm currently writing a simple serial passthrough program for the ESP32-C3 that reads from the integrated USB Serial/JTAG controller and writes to UART1, and vice versa. The code will gladly read data using

Code: Select all

usb_serial_jtag_read_bytes

but

Code: Select all

usb_serial_jtag_write_bytes

does not print any output to the console (checked using the IDF monitor and with PuTTY). Echoing the data back to UART1 confirms that it's read is working correctly, and the return from

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usb_serial_jtag_write_bytes

is nonzero (in this case 1). Does anyone have an idea as to why no data is sent to the PC via the USB-CDC?

Thanks!

[matheus.lemos]

Hello!
I'm having almost the same issue with my ESP32-S3. I could only see the print message when enabling "CONFIG_ESP_CONSOLE_USB_SERIAL_JTAG=y", but it enables the debug logs on USB either.

[matheus.lemos]

I found a workaround for my issue, I hope it could help you too. If you add the driver command "usb_serial_jtag_ll_txfifo_flush();" after calling "usb_serial_jtag_write_bytes", the tx buffer will be flushed and then you will be able to see the message in your serial.