My xiao nrf52840 sense can't find the port of uart with windows

connor · March 23, 2023, 7:26am

I download bootloader by j-link into xiao nrf52840 sense board,when i connect the usb of xiao nrf52840 to windows usb, it just show a nrf serial device,so how can i fixed to change to comX port of uart?

this is eth bootloader that i download into xiao board:

github.com

0hotpotman0/BLE_52840_Core/blob/main/bootloader/Seeed_XIAO_nRF52840_Sense/Seeed_XIAO_nRF52840_Sense_bootloader-0.6.1_s140_7.3.0.hex

:04000003F000AE1942
:020000040000FA
:1000000000040020810A000015070000610A0000BA
:100010001F07000029070000330700000000000050
:10002000000000000000000000000000A50A000021
:100030003D070000000000004707000051070000D6
:100040005B070000650700006F07000079070000EC
:10005000830700008D07000097070000A10700003C
:10006000AB070000B5070000BF070000C90700008C
:10007000D3070000DD070000E7070000F1070000DC
:10008000FB070000050800000F0800001908000029
:10009000230800002D080000370800004108000078
:1000A0004B080000550800005F08000069080000C8
:1000B000730800007D080000870800009108000018
:1000C0009B080000A5080000AF080000B908000068
:1000D000C3080000CD080000D7080000E1080000B8
:1000E000EB080000F5080000FF0800000909000007
:1000F000130900001D090000270900003109000054
:100100003B0900001FB500F003F88DE80F001FBD8C
:1001100000F0ACBC40F6FC7108684FF01022401CA7

This file has been truncated. show original

robert-hh · March 24, 2023, 8:50am

AFAIK, Windows decides which Com port it assigns to a device. You may be able to change that in the windows device manager. Besides that, the bootloader is responsible for uploading firmware. When pushing reset twice, if should offer a disk service to the PC, and a drive should pop up at the PC, into which you can upload a firmware. This is a ‘virtual’ drive, so it does not show a real file system at the board.