I have an Arduino Mega 2650 that i can no longer program. It no longer even finds it in the “serial port” list on my Mac, or my PowerBook. I can still program my Uno R3 without any problems, and the mega continues to function with the sketch i have on it right now, i just can’t upload any new code. Any thoughts?
The project i’m working on now controls four 12volt motors with a pair of SN754410NE h-bridges. I’m using the WiiChuck library to allow me to use Wii Nunchuck as an input to select a motor, direction and speed. I’m using a pair of RGB LEDs to indicate status and sending data like the motor number and speed via serial to a board i made which is a 4x 7-segment i took from an old alarm clock and is driven by an AtTiny85 and two shift registers. Everything is in working, just want to change the map values for the speed…
I was able upload the sketch, and make several updates / bug fixes, but all of the sudden i cant upload anymore. There really isn’t anything fancy in my code.
Thanks!
First, we need to know what error messages you are getting.
Second, it’s the Atmega16u2 that acts has a bridge to upload code to the 2560. You may have fried that chip or the firmware has been corrupted. You can try to reprogram the 16u2 by following this, http://arduino.cc/en/Hacking/DFUProgramming8U2
Thanks for the response.
I’m getting “dfu-programmer: no device present” when i try to update the 16u2. The commands in the instructions say at90usb82… is that correct for the 16u2? or is that for the 8u2?
If i hook up my Uno R3 and do a “system_profiler SPUSBDataType” from the command line (equivalent to “lsusb”) it finds this:
Communication Device:
Product ID: 0x0043
Vendor ID: 0x2341
Version: 0.01
Serial Number: 75230313833351404132
Speed: Up to 12 Mb/sec
Manufacturer: Arduino (www.arduino.cc)
Location ID: 0x06200000 / 3
Current Available (mA): 500
Current Required (mA): 100
But when i hook up the Mega 2650, it does not find it.
So, does it seem that the 16u2 is fried?
Is there any way to trouble shoot the hardware? It does power up using USB, but no connection
Can I use my Uno as ISP and program it like its a AtTiny?
It sounds like it’s dead. But maybe someone will jump in that has some ideas to troubleshoot it further.
You can still program the 2560 with the ICSP header located right next to the chip. You will need a programmer though. I have the AVRISP mk II. It will program any AVR chip and you can still use the Arduino IDE.