Angle sensor measurement procedures used to detect pipeline to tilt Angle, interface USES the SPI interface, SPI interface is a kind of synchronous serial peripheral interface, it is used in the single-chip 8-bit data synchronously receive send at the same time, the SPI serial clock SCK need 4 line, MISO, host, host input from machine output cable output from the machine input cable MOSI and low level effectively select line CS from machine. When SPI works, the data in the shift register is output bit by bit from the output pin MOSI (high in front), while the data received from the input pin MISO is displacement by bit to the shift register (high in front). After sending a byte, the byte data received from another peripheral device enters the shift register. The clock signal SCK of the main SPI synchronizes the transmission