Adding new Arduino-based boards

Loss of USB connection is usually a sign of TinyUSB not being correctly compiled.

First of all, try running the simplest possible sketch

#include <Arduino.h>

void setup() { Serial.begin(115200); }
void loop() { Serial.println("Hello"); delay(1000); }

(this may additionally need #include <Adafruit_TinyUSB.h> at the top) and upload that. Does it work? If not, additionally add lib_archive = no in your platformio.ini, this resolves some special issues in regards to linkage.

Thanks, this seems to work now. I had to include the Adafruit_TinyUSB.h and add lib_archive=no to the platformio.ini file.
Thanks a lot for your help!