Ok, total noob here. I would like to make a frequency counter that can display on a small oled, it needs to have 3 switchable offsets so at any one time it can display the same frequency from 3 different frequency inputs depending on which switch is active, frequency source to be measured would be a sine wave from a quartz crystal in a radio, in the range of 10Mhz to 30Mhz is this possible, and what hardware do I need to get started, size is also an issue so the smallest physical size of components is also a factor.