In this paper, a hardware in the loop simulation (HIL) is presented. This application is purposed as the first step before a real implementation of a Generalized Predictive Control (GPC) on a micro-grid system located at the Military University Campus in Cajica, Colombia. The designed GPC, looks for keep the battery bank State of Charge (SOC) over the 70% and under the 90%, what ensures the best performance in the battery bank according its technical specifications. The GPC algorithm was embedded on a STM32 microcontroller and the micro-grid model was embedded on an ARDUINO MEGA microcontroller.