The parameters of pi controller

Hello, I've working on 100w PV panel project and I need to design the boost converter controlled by Pi , I already calculated the value of L and C but I don't know how to find the parameters of pi , I've seen videos of how to tun it , I know the Vin and Vout but while developing the boost converter should I take the same Vin and Vout of my pv panel ?? And what about the powergui? Should it be the same too?