Integrate Bluetooth control to an existing Arduino code, how difficult?

General Discussion
1

I have a fairly long code which works on an Uno, it's a led lighting controller that runs up to 16 channels via a PCA 9685 pwm, it's displayed on a 16x2 LCD and controlled via a rotary encoder (I didn't write the code, it's open source)

There's quite a few menus and sub menus. My question as a non coder (last time I coded was in 1986) is how difficult is it, will I need to add lines to the Arduino code? I don't want to get in over my head, though I'm willing to give it a shot, the actual app building doesn't look too taxing.

I'm going to watch some more tutorials in the meantime.

Regards,

Stefan

2

The most important part is to understand how the data flows through the code.
From there, study how the timing (if any) works.