Hi Everyone, I have recently started dabbling into embedded projects with first working on an adapter for a i2c based controller and adding bluetooth support using one of the seeed nrf54l15 boards to get started. I modified the hog.c/h file from the bluetooth sample and now I can no longer connec…

Hi there, So I looks to be soft_bricked, Those links are for the nRF52840 Parts, Try this one, [image] Seeed Studio XIAO nRF54L15(Sense) | Seeed Studio Wiki Restore factory settings For XIAO nRF54L15 boards, a factory reset script is provided to recover the boa…

Hi, I just have a st-link device and put some probes on the pads on the back of the XIAO, however the reset script hits that error like in the bottom part of my post. If I need a jlink device then I could try that once one of those comes in.

You should be able to repair it simply with pyocd and the mass erase command twice. It always looks like it fails the first time and then it works the second for me. Connected just via usb.. No need for using the bottom pads. (Which can also work, it’s just harder)

I’ve tried this already unfortunately. the issue I’m having is the USB stack in general on my device is corrupted or got overwritten so it won’t even show up in windows even as a unknown device.

So there’s two mcus on the Xiao nrf54L15, the Nordic soc, and a seperate samd chip with cmsis-dap firmware on it. The secondary MCU provides the usb host interface to the usb C connector. You can access that samd MCU from the debug pads on the bottom, using SWD debugging. Sounds like something mig…

probably, I’m not sure where I could get a firmware file for flashing that, the firmware.hex given as part of the reset script is for the nrf side. I think the cmsis-dap firmware on the samd11 got screwed up.

I have a similar issue with nRF54

Hi there, So if the sam side is corrupt , albeit I don’t see how? The SWD pin set on the bottom can be used, The Git may have those files, but it’s a vanilla USB bridge hex AFAIK. Check the WIKI, link to the Github is there. HTH GL :slight_smile: Pj :v:

Everything was done in the same way, and the developers even responded by email, saying that it wasn’t the case, but maybe the board’s integrity had been compromised, or there was a short circuit somewhere, causing the com to stop working, but the bluetooth, microphone, and flash drive still functio…

I’m also experiencing an issue with the XIAO_nRF54L20A where the COM port disappears and I can’t upload files. So, was this “COM port disappearing” issue ever resolved?

Nrf54l15 Seeed no longer shows up in windows via USB

Products & Technology XIAO

msfujino August 8, 2026, 12:27am 13

I’ve created a rescue tool. If you’re interested, please check out the link below.