Re: Rasperry Pi fail
Pi is a success. If you want something closer to bare metal, then the PIC18F family and JAL to program it. Direct I/O and access to all HW directly, but a nice high level language that accepts in-line assembler.
There is even a board that takes Ardiuno shields. Though I'd rather knock up a PIC on veroboard (stripboard) with the I/O better laid out than the shields. USB only needs a socket. Libraries for GLCDs, text LCD, SDIO, FAT etc.