Uploading

To start i would make sure you have the newest driver and IDE.  If you do have the newest i would remove and do a clean install.  What operating system are you using?

Windows 7

If you are using windows 7 I would high recommend using Arduino ERW 1.0.3 IDE it comes with an installer that has all the newest drivers, the console also gives you more feed back so you know what AVRdude is up to. It's basicly the same as the original IDE but with a lot of helpful features added. Hope this solves your problem.

Fidel Salinas.

Many thanks but no, if anything it's worse. I have just tried it around a dozen times and not one of them succeded. This is with a sketch around 17k. It says "Uploading", I get one flash from the RX LED and then it just sits there doing nothing. If I then unplug the connecting cable, reconnect it, and try again I get a message saying it can't find COM 3 but after several more attemps it finds it and I get back to where I started again. When it can't find COM 3, if I check in Control Panel it tells me that there is a MEGA2560 on COM 3 and that it is working correctly. I've gone back to my old version (Arduino 1.0.1) and that worked on the second attempt.

John Waterman

I'm happy you've got it working, If you run into any more trouble i'll be more then glad to lend a helping hand.

Fidel Salinas.

I'm sorry Fidel but it seems that you misunderstood my response. Far from solving the problem, it made things worse. I cannot get the 1.0.3 IDE to upload AT ALL - not even a short sketch, and using the 1.0.1 IDE, uploading is still unreliable, although it does upload when it's in a good mood.

HOWEVER I have now got my hands on another Mega2560 and that behaves much better, although the 1.0.3 IDE will still not upload to that one. It remains to be seen whether or not this new board will be completely reliable using the 1.0.1. IDE but it has been so far. It seems that this new board is not an R3 whereas the older one was. The new one chooses to work via COM 4 whereas the other (R3) chooses COM 3. I don't understand why or whether this is of any relevence.

John Waterman

Maybe changing the COM port might do the trick it also might be the computer, do you have a laptop or second machine you can try uploading the new firmware with? it's an easy way to see if you've got a bad board on your hands. I'm sure we can get to the bottom of this.

Fidel Salinas

Unfortunately I don't have another PC to try. I don't know if it is possible to change the COM port myself - the boards automatically choose it themselves and don't seem to allow me to. My latest 2560 board (not an R3, and working on COM 4) is working quite well but not 100%. I suppose so far its uploading failure rate is less than 10% - which I can live with. The other board (R3, and working on COM 3) - when "in a bad mood"  was virtually impossible to upload to, although on other occasions was not so bad.

Every time when I check in Control Panel it tells me that I have a Mega2560 on whichever port and that it is working correctly. I have by the way, tried another connecting lead to the Arduino but that has made no difference.

In windows 7 Device Manager just double click on the mega on the "ports (com $ PTL" tree a proprerties window should pop up, click the "port setting" tab then hit advance and you should have the option to change the port.

Fidel Salinas

No luck I'm afraid. I changed to COM 7 - I also saw that it is possible to alter the speed, so I tried different speed settings but none of them were reliable. I could upload sometimes but couldn't manage more than about four consecutive uploads.

I did however see something which I don't know whether or not is normal. No matter which COM port I chose I got a warning saying, "This port has been opened by another application" and asking me if I still wanted to go ahead. I find it hard to believe that this is true - can it be that it is a problem with my computer there somehow?