I have written two simple Qbasic programs to control these tuners. The frequency can be
specified and as an option the VCO can be set to sweep around the set frequency.
The programs use the same I2C interface as is described in my XYdisplay.
I also have written a simple 16F84 assembler program to control the SF1216 tuner. The PIC (schematic) has a one-line LCD and two push-buttons to cycle the tuner through 8 preset frequencies and select two different IF frequencies to accomodate HRTP or PDUS reception of Meteosat transmissions. You could use this program as a starting point for your own experiments.
Here is a low-quality scan of the SF1216 datasheet