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标题: mma7455怎么用spi编程 [打印本页]

作者: hyz229426897 时间: 2013-8-12 22:32
标题: mma7455怎么用spi编程
void SPI0_Init() {
  SPI0BR=0x55;    //波特率2048
  SPI0CR1=0x5e;    //模块使能，主机模块
  SPI0CR2=0x10;
}
void SPI0_Send_Data(){
  cs=0;
  SPI0DR=0x08;
  while(!(SPI0SR_SPTEF));    //等待SPTEF 为0



  cs=1;

}
SPI0_Receive_Data(){
  cs=0;
  LCD_set_XY(1,1);
  LCD_write_char_my(font6x8[16]);
  while(!(SPI0SR_SPIF));

  return SPI0DR;
  cs=1;



}

void main() {
  Pll_Init();

  DDRA=0xff;
  DDRP=0xff;

  LCD_init();
  LCD_clear();


DDRM=0x2f;
MODRR_MODRR4=1;
  SPI0_Init();


  EnableInterrupts;


  for(;;){

//cs=0;
//PTM_PTM3=0;

SPI0_Send_Data();
a=SPI0_Receive_Data();

LCD_set_XY(0,0);
LCD_write_char_my(font6x8[a/100+16]);
LCD_set_XY(6,0);
LCD_write_char_my(font6x8[a/10%10+16]);
LCD_set_XY(12,0);
LCD_write_char_my(font6x8[a%10+16]);
delayms(3000);
//cs=1;
//PTM_PTM3=1;


  }
}
用示波器读sdi波型是0x08  为什么出来的数据总是0  求大神啊·······

作者: 冷落义墨 时间: 2013-11-8 12:40
我用51模拟iic模式读出来的也都是0 无语了

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