Help to solve pop when sound loops

Hi.

I hope this is the correct place to ask for help relating to ALSA's C lib?

I'm working on a wavetable project for college. Please see attached.

I've managed to create a wavetable containing a sine wave. The pitch can be altered via a frequency variable (f).

There is an audible popping sound when the sound loops. I have noticed that increasing the buffer size, postpones the pop.

I've been reading up on buffer > period > frames, but I don't know how to go about removing the pop.

Would really appreciate some guidance.

Thanks C