The OLED driver code is almost done and is giving an output, although noise seems to be an issue. I'm going to buy some DuPont jumper wires to connect directly to the Raspberry Pi rather than breadboard. 20Mbps over breadboard is pushing it really :) Here's a picture of the OLED displaying time, all written in C#!
I also decided that rather than make one board, I'd make a few extra plus some other boards such as an AD7190 analogue to digital converter (a very, very low noise one for bridge sensors such as a load cell or gas sensor). An AD9834 DDS board with a 50MHz master clock source, I can use this to generate any frequency I want up to about 15MHz useable in sub hertz steps. The last board is a CAN BUS controller such as used in cars and industrial control. The can controller is based on the MCP2515 controller and MCP2551 can interface. Here's pictures of the rough, not yet cleaned up, pcb's:
I'll update the git hub repository with my latest updated wrapper class and test modules so anyone can have a play. For my next trick, DDS board with scope pictures and code updates!