I tried to upload a program to my due and got the following error message:
Der Sketch verwendet 24788 Bytes (4%) des Programmspeicherplatzes. Das Maximum sind 524288 Bytes.
Erzwinge Reset durch öffnen/schließen mit 1200 bps auf dem Port COM9
C:\Users\CPR\AppData\Local\Arduino15\packages\arduino\tools\bossac\1.6.1-arduino/bossac.exe -i -d --port=COM9 -U false -e -w -v -b C:\Users\CPR\AppData\Local\Temp\arduino_build_961295/pwm_lcd_test.ino.bin -R
Send auto-baud
No device found on COM9
Set binary mode
Beim Hochladen des Sketches ist ein Fehler aufgetreten
Arduino is listed in the device manager with no failure.
additionally I got the following message during installation of SAMD Core:
Es konnte keine boards.txt in C:\Users\CPR\Documents\Arduino\hardware\Arduino_STM32-master\examples gefunden werden. Ist sie noch von einer Version vor Arduino 1.5?
Es konnte keine boards.txt in C:\Users\CPR\Documents\Arduino\hardware\Arduino_STM32-master\examples gefunden werden. Ist sie noch von einer Version vor Arduino 1.5?
This just means you have a folder named examples under C:\Users\CPR\Documents\Arduino\hardware\Arduino_STM32-master that doesn't contain a hardware package. Since the time of the version of Arduino_STM32 you're using that problem has been solved by creating a dummy library that contains the examples:
If that warning annoys you or you want to make it easy to access the example sketches via the File > Examples menu, you are welcome to reproduce that change. If you prefer to leave it as is that's fine, it won't cause any problems. You will only need to disregard the warning.
I tried to fix the original problem, but no Idea were to start...
During the tests (power supply, cable, drivers, SAM Core, IDE-reinstallation,...) I recognized, that the com-port gets lost in 9 of 10 attempts. In the 10th case upload works as expected...