According to the characteristics of

According to the characteristics of this design, the complex program control system with multi switch input needs to be good at dealing with the standard single chip microcomputer with multi switch input, instead of the small single chip microcomputer with simplified I / O port and program memory, and the functions of D / A and a / d need not be selected. According to these analyses, I choose p89c51ra single chip microcomputer as the main control device of this design. 51 single chip microcomputer has powerful bit operation instructions, I / O port can be addressed by bit, program space is as much as 8K, which is more than enough for this design. What's more, 51 single chip microcomputer is very cheap.