Thanks. I am using my Bus Pirate to do the SPI configuration of the ADF4350. I have Python code that will write the reesgtirs in the correct order. I use the ADF4350 register tool (Windows application) from Analog Devices to compute register values, then I put them into the Python code. It would be fairly simple to modify my code to assume a certain reference frequency and configuration, and have the code calculate the appropriate PLL settings. I can post the code to my GitHub repository if you're interested in building on it.