| This paper considers maximizing coverage quality in Internet of Things (IoT) networks using Unnamed Aerial Vehicles (UAVs) to augment the link from solar-powered devices to a sink/gateway. Specifically, it aims to {\em jointly} optimize the assignment of UAVs to hovering points or a charging station, time in which devices monitor targets, and the amount of data transmitted by devices. These quantities are optimized over a given planning horizon using a Mixed Integer Linear Program (MILP). Further, this paper presents a heuristic method named Decoupled Energy Aware Algorithm (DEAA) to optimize the said quantities. In addition, it outlines a Model Predictive Control (MPC) approach that only requires current and historical energy arrivals information of devices. The simulation results showed that DEAA and MPC achieved $80.58\%$ and $61.19\%$ of the optimal results computed by MILP. |