Context: On a Win8.1/Leonardo/Arduino IDE system,I have managed to successfully install the leonardo driver on COM8, the upload goes well and I am able to bring up the serial monitor. The sketch runs correctly.
If I monitor the Device Manager during these activities, I see the following: as avrdude
begins upload the port changes to COM7 (expected behavior), when the upload completes, the port changes back to COM8 after about 10 secs. Serial monitor operates on COM8.
Now I try the same sequence of operations again. This time the upload seems to complete successfully but instead of COM7 changing back to COM8, it disappears from the device manager. However, if I look at the port list in the DM properties/port settings/advanced/port list drop down, I see COM8 is in use. The IDE does not provide it as a choice in the tools/port menu and the next attempt at upload fails due to COM8 being in use.
This behavior is intermittent. I can have a number successful uploads before I get the lost COM8 behavior. I can recycle to a usable COM8 in the Device Manager by:
- resetting Leonardo
- quickly right clicking the COM7 instance that appears in port(COM&LPT). then
selecting uninstall (deleting driver). When I exit from the dialog, COM7 is
gone. - resetting Leonardo produces “Arduino leonardo” under Other Devices. Right
clicking it, entering the update driver dialog and accepting the found drivers
installs the driver.(at this point there is no reference to either COM7 or COM8
in the DM). - resetting 1 – 4+ times yields COM7 under ports(COM&LPT) which after 10
secs either changes to COM8 or disappears.
My question: Does anyone know if this is a problem with avrdude/Leonardo due to its USB nature, a Win8/Leonardo/avrdude problem or my particular circumstances. If it is a problem others also have, is there a work around?
I have seen posts that say there is a problem with avrdude changing back to the original COM port after kicking Leonardo as part of the upload process, but I have not found a work-around mentioned.
Anyway, any ideas would be greatly appreciated.