Serial switching value collecting system based on SPI bus

The utility model discloses a serial switching value collecting system based on single program initiation (SPI) bus which comprises a segregating module, a converting module and a CPU collecting submodule. Anti-interference processing of a parallel switching value signal is conducted by the segregating module. The parallel switching value signal is converted into serial SPI transmission data by the converting module. A central processing unit (CPU) is quickly informed of the changes of the switching value signal through a way of suspending response by the converting module. A current time reading is realized. The serial switching value collecting system based on SPI bus is simple in structure, strong in anti-interference performance and capable of guaranteeing reliable collections of the switching value signal.