I have been using the arduino for a long time but this is the first time I have tried the SPI library. The command is very powerful but I have an issue with the SetDataMode documentation. The explination of SPI_Mode(0123) in the main SPI Library page is good.
" The SPI standard is loose and each device implements it a little differently. This means you have to pay special attention to the device's datasheet when writing your code. Generally speaking, there are three modes of transmission. These modes control whether data is shifted in and out on the rising or falling edge of the data clock signal (called the clock phase, and whether the clock is idle when high or low (called the clock polarity). The three modes combine polarity and phase. The SPI.setDataMode() function lets you set the mode to control clock polarity and phase according to this table: ..."
But should be moved to the setDataMode() page since that is where the SPI_Mode variable is used. It took me a while to find the table and i found it on someone elses web page before I found it in the documentation.