大家好，   我有一个设计要做PIC 18F4550 和MEMS 用spi连接 然后用lcd输出。   spi 我从网上下了一个 code,不知道能不能用。大家能看一下吗   MEMS我用的是LIS331DLH，因为太小的原因，我用STEVAL-MKI089V1代替。   下面的两个附件是LIS331DLH 的DATASHEET 和 STEVAL-MKI089V1 的电路图。     #include <p18f4550.h>
#include <spi.h>
#include <delays.h>
#include <lis331dlf.h> // Made by me
#pragma config WDT = OFF
#pragma config FOSC = XT_XT // 4 Mhz XT #define SPI_CS PORTEbits.RE2 // pin#10 as Chip Select unsigned char address = 0, data = 0;
unsigned char var, x_low; void byte_write (unsigned char address, unsigned char data);
unsigned char byte_read (unsigned char address);
void initialize (void); void main (void){
 initialize ();
 SPI_CS = 1; // Transferred disabled
 OpenSPI(SPI_FOSC_4, MODE_11, SMPMID); // SCL = 1 MHz, MID sampling
 
 byte_write (DATA_FORMAT, 0b00001101); // SELF_TEST = OFF, SPI = 4 wire, INTERRUPTS active high, RESOLUTION 16 bit, left-justified, 4g (01)
 byte_write (BW_RATE, 0b00001000); // Set sensor refreshing 400 Hz, LOW_POWER = OFF
 byte_write (FIFO_CTL, 0b00011111); // Bypass mode (00), TRIG linked to INT1, all zeros would be a reset value  byte_write (POWER_CTL, 0b00001000); // Normal operation, starting measuring
 
 while (1)
 {
  x_low = byte_read (DATAX0); // x_low is the low part of the X axis register   if (x_low != 0){
   PORTD = x_low;
   Delay1KTCYx(300); // LED blinking could be too fast so I have to put a delay
  } 
 }
} void initialize (void){
 TRISE = 0; // For Chip Select (output)
 TRISD = 0; // Output
} void byte_write (unsigned char address, unsigned char data){
 SPI_CS = 0;
 var = putcSPI(SPI_WRITE);
 var = putcSPI(address);
 var = putcSPI(data);
 SPI_CS = 1;
} unsigned char byte_read (unsigned char address){
 SPI_CS = 0;
 var = putcSPI(SPI_READ);
 var = putcSPI(address);
 var = getcSPI();
 SPI_CS = 1;
 return (var);
}   此帖出自小平头技术问答