Hi,
To program nRF52840, do I have to double-press the RST button every time to enter the bootloader state? I found this quite tedious. Is there another approach, or is this the way?
Thanks
Hi there,
The short answer is NO, If the code you sent it wasn’t well behaved or experimental, a small amount of code can get in the way of flashing on the fly with the 16 null chars and low speed mode. All things set up correctly and the proper ports are set. (in BL mode the com port may change) You must Select the board and port even if it’s recognized in the status bar at the bottom. Reselect it again b4 you click upload. 9 out of ten it fly’s without BL mode and the double reset pushing.
Also if slightly corrupted in the BL memory area it would be required after which you can drag and drop a Uf2 file , like the RGB LED test code demo with bootloader, over in the Uf2 file thread discussion, grab the zip file there and drag the UF2’s it contains to quickly reprogram and load a clean Bootloader in to The Xiao.
HTH
GL 
PJ
It’s not unusual to do it the first couple runs but once the process is down it isn’t required all the time. 
1 Like