The topic of this paper is the development of compact models reaction-advection-diffusion phenomenon. From a mathematical perspective, biological systems that involve such phenomena are described by partial differential equations. Our approach consists in discretizing these equations according to the finite-difference method and converting the resulting ordinary differential equations into an assembly of elementary equivalent electronic circuits that are simulated with SPICE. The main interest of this approach is the ability to couple such models with third-party SPICE models of electronic circuits, sensors and transducers as well as biochemical models that can also be written in SPICE. The tool is validated on simple problems for which analytical solutions are known. Then, our simulator is compared to a reference finite element simulator: COMSOL Multiphysics.