Thanks for the input Lefty
I see from this datasheet Intelligent Power and Sensing Technologies | onsemi
That the tip122 I was using before I melted the 2n2222a has the SOA
but this datasheet for the MPS2222a I was using does not Motorola MPS2222A datasheet pdf
or is it called something different in this datasheet.
I should have worded that question about the wall wart better, since its only rated to output 1000mA should that not be the maximum my multimeter can pull from it through its 10A fuse when testing it?
Would the 2n2222 burn out first and not pass any more voltage back to the Arduino's digital out pins? And in fact my Arduino is safe? If so why does it smell like smoke and the 2n doesn't?
Thanks
Chris