ESP32 S3 VM issue with USB serial CDC mode

[Sean shao]

When trying to compile the ESP32 S3 firmware, the firmware can be flashed into the board. However, once completed connecting the computer USB serial port programs the S3 in CDC serial mode. In this mode, it is not possible to connect the board to the IDE.
If you are using an S3 board that has a serial chip, this problem will not occur.

[John Maloney]

Thank you for mentioning this; it surprised me, too.

My ESP32-S3 dev board (and perhaps yours?) has two USB connectors. One is for debugging and programming the chip. The IDE cannot communicate with the board through that connection. Instead, you must connect USB cable to the other USB port, the one with a USB-serial chip. I believe the USB-serial chip connection can be used to install firmware, as well as connecting to the IDE.

I assume that ESP32-S3 boards with only have a single USB connection use a USB-serial chip.

In short, if you have a ESP32-S3 board with two USB ports and you've installing the MicroBlocks firmware but it isn't connecting to the IDE try switching the USB cable to the other port.

[Sean shao]

Many of the S3 boards I've tested have only one typeC usb port. After flashing MicroBlocks VM and connecting to IDE, you can only find one serial port like USB JTAG/Serial debug unit.
e.g. M5Stamp S3 , M5core3 ...

[John Maloney]

Can those boards connect to the MicroBlocks IDE?

[Sean shao]

no, they can’t.

[John Maloney]

This link may be helpful:

https://community.platformio.org/t/esp32-c3-framework-arduino-serial-print-usb/30464/2

[Sean shao]

build_flags =
    -D ARDUINO_USB_CDC_ON_BOOT=1

yeah, It’s working. Thanks

[Sean shao]

build_flags = -D ARDUINO_USB_CDC_ON_BOOT=1

[John Maloney]

Hooray!