I have successfully tested two Meshtastic Nodes based on RAK4631 (WisMesh & Starterkit with Solar). However, after weeks, I lost connection.
A probable reason could be that the power of the battery was too low. But I am not sure.
If I power the WisMesh via USB, the red LED is on. I see a serial connection in the device manager, but nothing happens else. I tried to reinstall firmware resp. bootloader but cannot switch the device to Bootloader Mode.
Any ideas?
Hi Dr @ckuehnel ,
Welcome back here in the Forum 
As for this issue on Meshtastic, there is pending issue/s in the Meshtastic FW that losses configuration in flash and other flash related issue. One of the recent PR should fix this. Likely to happen during reset or low battery scenario. I’ve experience this myself and hopefully get fixed on the next FW release.
You can still detect its serial so a double click reset should enable its UF2 FW mode or you can force it via software using - https://flasher.meshtastic.org/. It is advisable to upload the nRF52 FW reset included in the Meshtastic FW folder before uploading the Meshtastic FW itself. With the nRF52 FW reset, it is required that you open a serial terminal and hit enter to clear up any bad stuff that happen in the flash.