Friday, August 23, 2013

Arduino Mega 2560 r3 Doesn't Show Up in Tools Menu

Recently, I have had problems with my Arduino Mega 2560. Serial communications would drop in and out. It would not show up in the Arduino IDE Tools menu. Annoying stuff. Looking around on the internet, it appears that this is a fairly common problem, so I thought I would post what I know about a solution.

If your Arduino Mega doesn't show up in the Tools menu, the first thing you need to do is open the device manager (on Windows. If you have a Mac then you should mail it to me and go by a Windows machine). From the device manager we can further diagnose the problem.

1) Your Arduino shows up nicely under the COM ports tab. This is quite possibly the most frustrating problem, and as far as I can tell no one really knows why this happens. Here are some things that I did that sometimes worked. Try a combination of them.

  • Disconnect and reconnect the Arduino
  • Re-install the Arduino Drivers 
  • Re-install the Arduino Drivers deleting them when you remove them. ( I believe there was an update to the Mega driver somewhere around Arduino 1.0.2)
  • Restart the Arduino IDE
  • Turn off  your WiFi (My computer has bluetooth built into the network card. Bluetooth COM ports can cause problems sometimes. Turning off networking solves this).
  • Reinstall the ATmega16U2 firmware. (Instructions HERE)
  •  Get frustrated and go work in your garden
2) Your Arduino shows up as an unknown device. Install the drivers. I can't think of any other reason this would happen.

3) Your Arduino shows up as an unknown Atmel device. The Arduino Mega 2560 r3 has a ATmega16U2 that acts as a USB to serial chip. If you are getting an unknown Atmel device it means that this chip has been put into DFU mode. This is not the end of the world. Usually you can just disconnect and reconnect the Arduino, and it will go back into it's normal mode. If that doesn't work see my previous post on this subject.

4) Your Arduino shows up as an Atmel device called ATmega16U2. Well this means the same thing as above. It is in DFU mode except you have already loaded the Flip programmer driver. You have already started the process, so go HERE and finish.

5) Your Arduino does not show up in the device manager at all. This is a pretty major problem, but I found this one almost freeing. You can try various things. If you have an external ISP you may be able to reflash the ATmega16U2 and save it. I believe there are some instructions for doing so in a README file in the Arduino firmware folder. You should try a different USB cable obviously. Wiggle the wires. Blow out the connection with air. However... the chip may be fried. What does this mean?

If it is just the ATmega16U2 that is trashed then you can still use your Arduino Mega! Now you will just need an external programmer to program it. I recommend having one of these anyway. A USBtinyISP is maybe $15. I have used it extensively with ATtinys and even detail how to use it with a Mega HERE.

But now you want to get that nice Serial Monitor for debugging. Well that again will require extra hardware. You will need an external USB to UART cable. I talk about them HERE. Mine was $4. It's a worthwhile purchase anyway.

If none of those things tickle your fancy, buy another one. Places like HobbyKing sell them for less than $20 (HERE). Look for "Arduino compatible" boards. No one likes a counterfeit.

One last problem that I want to throw in here. The Tools menu freezes or crashes. There are mentions of this HERE. Like I said above, turn off your WiFi. You can also look and see if there are any Bluetooth scanning programs running. I haven't found any quick way of doing this besides looking through the system processes and closing stuff that sounds suspicious. Believe me, I know how annoying this problem is, but that's life. Arduino 1.5 does seem to do a bit better.

If you have other ideas, suggestions, or words of encouragement comment, and let the world know. There may be other things out there you can try.I hope this brings you success. Good Luck!

No comments:

Post a Comment