ABSTRACT
Due to limitations of Arduino board, even Mega Arduino board cannot provide sufficient interfaces in one board, and therefore 4 Mega Arbuino boards are used to control at two levels. At the first level, one Mega Arduino board is used to collect all data, and one Mega Arduino board can provide sufficient data input ports. But there are not sufficient output ports. At the second level, after the first Arduino board collects and processes all data, the data are sent to another Arduino boards which will send the data to connected installations. Since there are several installations and two-level data management structure, simulation, refinement and adjustment is required in circuit design to achieve highest reliability and simplest wiring.
