Need help!
My new UNO has been working fine for the last few days, but it has been using com4 instead of com3. Not sure why, but didn't think it mattered. So I go on youtube and watch several of Jeremy Blum's tutorials for the arduino and I come to tutorial 6 which tells how to use a pot to control the brightness on a small screen made by the "Processing" program. At first, I couldn't get it to work, and the Processing program wouldn't read the UNO data coming in. I thought maybe it was because Processing was looking at COM3 while the UNO was talking to COM4. So I fiddled around and was able to reinstall drivers and finally made the UNO to be on COM3 but that still didn't fix the problem. Finally, quite by accident, I discovered the problem was that the Arduino IDE serial monitor was in view and it was displaying the digital value of the pot and therefore Processing couldn't see the data. So I closed the serial monitor and it worked. Everything worked just like in Jeremy's example. So I went to bed with a big smile on my face at 3am. This morning I go to play around with the UNO again and it won't upload anything at all. Before, when the UNO was plugged in via USB THE LED (I think it was the one at pin 13) would blink on and off continuously until I uploaded a sketch. Now, it doesn't blink anymore; all I get is a steady "ON" LED.
In Device Manager, I see COM3 says Arduino UNO (COM3), and underTOOLS in the IDE it clearly says "COM3" and "UNO" are selected.
Every time I try to upload anything I get the following error:
Binary sketch size: 1484 bytes (of a 32256 byte maximum)
avrdude: stk500_getsync(): not in sync: resp=0x30
avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51
I've tried that several times. Is it possible the UNO got damaged through, say, static discharge? I haven't dropped it, exposed it to moisture or temperature extremes or high voltage or anything. What else could it be?
To rule out things I would find another PC, that can't be that hard these days (eg. a laptop). Install Arduino on that and see if you can program the board. That rules in or rules out the board itself.
Also try a re-install of the Arduino IDE on your main PC.
Why didn't I think of that! OK, so I installed arduino on my daughter's laptop (same type - hp pavilion, Windows Vista) and got it to work. The only catch is: it would only install on com5! Anyway, I got a sketch to upload and it works. So I know the UNO still works ok. Went back to my computer and it doesn't upload and gives same error message. Device Manager still shows com3 Arduino UNO. I'll try again to reinstall arduino IDE.
I would first just try deleting the driver and reinstalling it, as it sounds like the IDE is ok, just the USB driver borked. Don't be concerned so much about what comm port number gets assigned, just figure out which has been assigned to your arduino driver on your PC. Simple test is to start the Arduino IDE with no arduino board plugged in. Check the comm ports avalible and these are the one(S) that are NOT your board's assigned port. Then close the IDE, plug in your board and reopen the IDE and check the serial ports avalible. There should be one additional new one and that is your Arduino boards port number. Every PC is bound to have differences in comm port assignments, so you just need to learn which is valid for your arduino board(s).
OK. Did just as you said. Actually I've tried uninstalling and re-installing both the IDE and the drivers so many times I can do it in my sleep!
When I unplug the board, the IDE still shows com3 with a check-mark. I plug in the board. It shows the same thing. I uninstall the driver, it shows the same thing. I unplug, still same thing. I plug back in and uninstall the driver software, still the same. I uninstall the driver AND the driver software along with the whole Arduino download package. I put it in recycle bin and flush it to China, re-download from Arduino, and go through the whole installation process, and it still shows com3 with a check-mark. I plug in the board and it looks for driver software, can't find it, asks for CD-rom or instructions to driver and I send it to the recently-downloaded driver folder. It finds and installs it and says thank you (jk) and it still shows com3. Device Manager still shows Arduino UNO com3. IDE still shows com3 with a check mark. Try to upload the example Blink sketch -- still same error message.
The only thing I can think of now is to maybe upgrade to Windows 7 -- do you think that would help?
I'm using it on XP without any problems. Also on a Mac. Upgrading to Windows 7 would probably help in the sense that you are starting from scratch. But a re-install of Windows Vista/XP would do that.
So I fiddled around and was able to reinstall drivers and finally made the UNO to be on COM3 but that still didn't fix the problem.
I'm a little doubtful about what this "fiddling around" did.
There are different driver installation instructions between a Uno board and the prior but still supported FTDI based boards. Are you sure you are following the driver instructions correctly for a Uno. I don't have a Uno so I can't baby step you through it.
I've got a Uno, but I am reluctant to try to step through it. Windows is like a delicate flower - if you touch it, it disintegrates. Also, once a driver is installed it is hard to get rid of it. But, "fiddling around to make it appear on COM3"? Did that involve the Registry?
Did you check the troubleshooting guide: http://www.arduino.cc/en/Guide/Troubleshooting#upload? There are some other things that can cause this sort of problem, like overly aggressive firewall software, or drivers for USB cellular internet dongles, or just a bad USB cable.
Well, finally after an unknown sequence of unplugging, restarts, and reboots, I finally got it to work. Wish I could tell everyone who helped me exactly what it is that fixed the problem, but I'm just too computer illiterate. One thing that's interesting, though: every time I use the Processing program to try to read from the serial port, I have a similar problem of not being able to upload to the UNO. Every time, COM4 appears out of nowhere. Strange.
But anyway, thanks to everyone for your assistance.