Hi srig, sorry if i didn't work on this since a lot of time but i just have one suggestion to avoid flickering.
  • 1. have a PIC with 1 internal PWM
    2. Use this output with a transistor or mosfet to source voltage to LEDS

so that will be more easy to create your code. The only thing you will have to work with is with HPWM.

better like that ?