ESP32 Forum

Hi,

I am using USB CDC on ESP-C3-13 module and connecting to my notebook via USB interface. When I push boot button my notebook is able to see COM port and able to download program successfully into module. After I reset module USB connection drops normally, but Windows create a notification with an "USB Device Not Recognized" error. While figuring out the problem I found out that I set GPIO18 andGPIO19 pins to INPUT_PULLUP. After I remark those lines USB device is able to find by notebook.
This situation is same for Serial.* commands too.

Is it not permitted to set GPIO18 and 19 to INPUT_PULLUP while using USB CDC scenario? And why I am facing same situation when I use Serial?

Thank you.

Orkun Gedik

UPDATE:

No problem with Serial. Problem only on GPIO18 and GPIO19

GPIOs 18 and 19 are the ones the USB peripherals use.
If you use pinMode on them, you are basically making them behave as normal GPIOs, therefore losing the USB functionality.

alecamaracm wrote: ↑

Sat Aug 12, 2023 2:20 am

GPIOs 18 and 19 are the ones the USB peripherals use.
If you use pinMode on them, you are basically making them behave as normal GPIOs, therefore losing the USB functionality.

Thank you for your reply, alecamaracm. I will take this into account.

Best regards,

Orkun Gedik