I have a uno3 and the uno2.
Here the deal I uploaded the ArduinoNunchuk example code in the Uno2 and it doesn't work it's like the SDA and SCL are not hooked up.
So pull out the Uno3 and and load the same code and it works fine.
So is not the SDA SCL lines in the same place on both I found this
Revision 3 of the board has the following new features:
1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible with both the board that uses the AVR, which operates with 5V and with the Arduino Due that operates with 3.3V. The second one is a not connected pin, that is reserved for future purposes.
It works on the uno rev3 but the uno2 it doesn't work on. I found the sch for a Rev2 and it doesn't even show any SDA or SCL lines.
but there both ATmega328 So it looks like they should be the same.
CrossRoads:
Maybe you've got a bad part then.
If you swap the 328s between the 2 boards, does the R2 work and R3 not work?
That was next on my list I'm looking for the tube of 328 I have to swap one and see.
My uno rev3 has had the chip pulled so much i've about broke the pins off lol.
Well I couldn't find the tube of 328s I have so I pulled chip and swaped them they both work now maybe the chip wasn't seated good or something on the Rev2 I guess
