Just starting out here, with an Arduino M0 connected to Windows 7. I did the usual blink sketch, and it was slow to upload, but it did upload. I am now trying to get it to blink an external LED, and it will not upload.
Following the Evil Genius" thing, I originally set the port to COM3, but only got it to work on COM1. When I checkerd back, COM3 had disappeared from the list, and "COM5 (Aduino M0)" was there. I tried that, but got the same result. And now I only have COM1.
These are the last few lines of the output in verbose mode:
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer
avrdude: ser_recv(): programmer is not responding
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: ser_recv(): programmer is not responding
avrdude: stk500v2_ReceiveMessage(): timeout
Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
The suggested link did not have those error messages, so I am not sure how to proceed.