I got a problem with xiao sense, it doesn’t show the port after installing the micropython/circuitpython firmware. However, if I go in bootloader mode, it will show the ports. I tried uploading example code in arduino and it works as intended. Actually, it was fine as of yesterday, and I leave it plug the entire day for testing and now I cannot access its port. Any tips or should I use J-link to reflash its firmware? Any recommendation is gladly accepted. Thank you!
HI there,
and welcome here.
If while in bootloader mode you can see it show up as a drive letter in Windows, Head over to the drag and drop thread and unzip the uf2 file for the RGB led blink test and drag that to the drive it will load, reset and start blinking the RGB Led in sequence and print the color out of the serial port.
After that, uploading and programming can begin Normal again. The problem was something messed up the structure of the flash or memory. You can restore it also with the Jlink , however the Uf2 is way easier.
Which BSP file was installed when you added the Micro/Circuit P stuff. Look at the WiKi and try the conversion again.
HTH
GL 
PJ
Hello PJ,
Thank you for the warm welcome.
Actually, the xiao sense is working normally for how many weeks, and yesterday till this morning, I let it run for testing. It was working fine, and I can access its serial port as of yesterday, but when I plugin it today, there’s no serial port. So, I tried to troubleshoot it, like the drag and drop for the firmware, where I flash the circuitpython firmware. The LED indicator will blink stating that the firmware is successfully flashed but there’s no serial port and the file manager name "CIRCUIT PYTHON’ well not pop-up. So, I tried reflashing the micropython firmware (since the project runs on micropython), but again there’s no serial port. Then, I tried using the Arduino IDE, and upload basic program (e.g., LED blinking), and it works. But this is only applicable if you are in bootloader mode. I also tried to restart my pc and trying plugging to different computer and also using different type c cable, but the result is the same, it doesn’t show the port in device manager.
Is XIAO listed under “Universal Serial Bus Devises” in the Device Manager?
If so, right-click and run Update Driver. When you do, select “Browse my cpmputer for drivers” and “USB Serial Device”. If you are lucky, the port will be restored.
Hello msfujino,
The XIAO was not listed on the Universal Serial Bus Devices, and if I plugin the XIAO, there’s no update on the device manager, unless if I’m on a bootloader mode. I think the problem is in nrf52 chip itself.
If you haven’t tried it yet, why not re-flash the firmware?