Hello,
The -o suffix denotes a project which was built with the compiler setting for optimized build. This means there will be no debug capability enabled in this build. It also means the memory size on the target required by the application will be smaller, depending upon which optimization level was selected.
The -d suffix denotes a project which was build with the compiler setting for debug. This means this project can be used with a debugger, but will require more memory space on the target.
As it is always important to be aware of size when developing applications for embedded systems, it is possible to develop an application which would fit onto a given MCU when optimized, but could not fit when built for debug.
Hope it helps,
Mike
