An adaptive controller for regulating and dimming problems of LED current control is developed in this article when the LED driving system is considered as a class of unknown nonlinear discrete-time systems. The controller is designed by a Fuzzy-rules emulated network (FREN) with direct human knowledge as IF-THEN rules of the controlled plant. The online learning algorithm is established to tune all adjustable parameters of FREN with the convergence analysis. The prototyping system is constructed by using Raspberry Pi model B as a main processing unit. Experimental results validate the satisfied performance for both current regulation and dimmer applications with positive and negative slopes.