Use an IC to tuner fm transmitter

[GiTS]

I'm making one of those simple FM transmitters. It uses a variable capacitor to tune. According to the writer of the tutorial, it is difficult to tune the circuit and RF is generally finicky.

How would I use a microcontroller to tune the circuit?

Thank you,
-GiTS

 

[Jiggy-Ninja]

My best guess, extrapolating from what I've learned so far and from what little I've ead about uCs, is a varactor (diode specially constructed to increase the reverse bias junction capacitance) with an integrator to change a Pulse Width Modulated signal into a steady analog voltage level.

The RC values of the integrator would have to be carefully chosen to minimize ripple, so maybe (probably) there's a better way.

All diodes have reverse junction capacitance, and could in theory work, a varactor is just specially constructed to optimize that aspect.