Based on the microcontroller (MCU), a universal digital hardware experimental circuit for four-dimensional chaotic system is designed, from which 9×7-grids scroll chaotic and hyperchaotic attractors are generated. Reference [1] has presented a four-dimensional multi-scroll hyperchaotic system extended from Colpitts oscillator model. In this paper, a new four-dimensional grid-scroll hyperchaotic system is constructed by introducing a unit sawtooth wave function to replace the triangular function in the original system, which is realized by utilizing MCU digital hardware implementation easily. Analysis and numerical simulations are performed for the formation mechanism of grid-scroll attractor in the new system. By using Euler algorithm to discretize the proposed grid-scroll hyperchaotic system, an attractor with more grid-scroll number than that of the original system can be generated in the effective dynamic range of the experimental circuit. Experimental results verified the feasibility of grid-scroll hyperchaotic system based on MCU implementation.