Seeeduino Xiao Zephyr Problem

Hi !
I’m currently trying to run Zephyr on Seeeduino Xiao (SAMD21) with the help of the PlatformIO IDE but I’m facing an issue.
I’ve created a new project running on Zephyr framework and built this bit of code :

#include <zephyr.h>
#include <stdio.h>

void main(void)
        printk("Hello World :)");

The building process seems to work properly as well as the uploading to the board.
But once the file is on the board the Xiao isn’t recognise anymore (COMx dont show up), and the blue TX LED doesnt blink at all.
I first tought it was a bootloader problem and tried a new one but it doesnt seems to work.

Thank’s :slight_smile:

platformio.ini configuration :
[env:seeed_xiao] platform = atmelsam board = seeed_xiao framework = zephyr

Since PlatformIO declares

the used Zephyr version is seeduino_xiao, which declares as its serial and console output device as

which is a hardware UART at 115200 baud, not USB, on the pins

PB9 and PB8, which, per schematic is the pin labeled “A7” (RX) and “A8” (TX).

So, if you connect a USB UART adapter to thoses pins (and GND) and open the serial monitor at 115200 baud (monitor_speed = 115200 in the platformio.ini), you should see that output.

For console over the USB-CDC serial, see zephyr/samples/subsys/usb/console at main · zephyrproject-rtos/zephyr · GitHub.

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