I had previously begun working on Arduino libraries for the different versions of the Serial NVM board, and last weekend I completed the library for the M95M02 SPI EEPROM and tested it alongside the MCP23S08 to ensure the chip select schemes and timing all worked well together, which they did. I had a little trouble at first writing and reading back a test string, but thanks to my USB logic analyzer, it was an obvious timing issue of not waiting for the recommended write time ‘tw‘ after releasing the chip select before attempting to read back the data. The library for the M95M02 is also open source and can be downloaded from this repository here. Next step is to create a new library that wraps these two libraries into one, allowing access to all the functionality from one library while also allowing the entire array of chips to be accessed as though it were one contiguous chuck of memory.
Last weekend, I had a chance to catch up on development and testing of code for the Serial NVM boards. As you recall, I had a slight mishap on the last rev of boards ordered from OSH Park, to which I have added a jumper wire and am using these for code development and testing. Last month I completed the Arduino library to drive the Microchip MCP23S08 serial IO expander and can be downloaded from my bitbucket repository here.