AVR Freaks

I have been using xc8-avr, with the build tools option set to look at the avr/bin folder to give the full gui compiler options and the ability to use c++ (same files, without the xc8 indirection). The default xc8 compiler options is a limited set (in the gui anyway), and no c++ support.

I have been using it for a while just on the tiny416 and mega4809, and I would say its mostly ok but there has always been little problems that 'shouldn't be'. I have been attributing any problems to mostly myself, since I am using c++ and well, maybe I'm not that good. In my defense I have a pic32mm that I started with very little knowledge of c++ and worked my way to a full set of drivers including usb, and I have had very few problems along the way- everything just works on that thing (and with the SNAP, debugging is fast and easy).

Working with the tiny/mega today, I seem to have discovered that the linker doesn't always know what its doing. A static var was getting overwritten somehow, and eventually discovered that there was another static var given the same address. Nice. I saw this thread and decided to give the 'toolchains for avr' linked to above a try. I simply downloaded, extracted to a folder, pointed the build tools to the bin folder, compiled, and it worked (that took about 5 minutes to do). Now things are starting to act normal. I hope this was the primary cause of my little problems. Since code is continually changing, its a little hard to distinguish code problems from other problems- one minute it works fine, so code must be good, then make some minor changes and it goes strange again (and then thinking latest code was the cause). If the linker all along has been throwing little problems at me from time to time, then that would explain what has been going on.

They are making quite a few changes in their version of gcc/avr, and in their defense they are not claiming to support c++ in this version, but in any case lots of changes means lots of potential to make mistakes that will take time to work themselves out. I had previously thought that since all the latest work being done was on the 'xc8 version', that was the place to be. Now I'm thinking the gcc branch is probably the 'stable' branch, and stable is good.