标题: ad7799单片机驱动程序 [打印本页]
作者: 微风寒    时间: 2017-3-13 17:42
标题: ad7799单片机驱动程序
例子一：


  3. sbit AD7799_CS=P1^4;
  4. sbit AD7799_RDY=P1^6;

  6. //SPCR SPI控制寄存器

  8. //SPSR SPI状态寄存器

  10. //SPDAT SPI数据寄存器
  11. void SPI_init(void)
  12. {
  13. SPCR=0x5e;//SPI控制寄存器，中断禁止，SPI使能，高位在前，主机模式，时钟空闲时为高，后沿触发移位，时钟分频64
  14. SPSR=0x00;//清中断标志位
  15. }
  16. /*--------------------------------------------
  17. 写AD7799寄存器函数
  18. WriteData：要写的数据
  19. ----------------------------------------------*/
  20. void WriteByteToAd7799(unsigned char WriteData)
  21. {
  22. SPDAT= WriteData;
  23. while(~SPSR&0x80); //等待数据发送完
  24. SPSR=0x00; //清中断标志位

  26. }
  27. /*--------------------------------------------
  28. 防止时序混乱，实现再同步
  29. ----------------------------------------------*/
  30. void WaiteRDY(void)
  31. {
  32. unsigned int count=0 ;
  33. while(AD7799_RDY)
  34. {
  35. count++;
  36. if(count>20000)
  37. {
  38. //reset ad7799
  39. WriteByteToAd7799(0xff);

  41. WriteByteToAd7799(0xff);
  42. /*----------防止时序混乱，重新同步----------*/
  43. WriteByteToAd7799(0xff);

  45. WriteByteToAd7799(0xff);

  47. AD7799_init();
  48. break ;
  49. }
  50. }
  51. }

  53. /*--------------------------------------------
  54. AD7799初始化函数
  55. ----------------------------------------------*/
  56. void AD7799_init(void)
  57. {
  58. AD7799_CS=0;
  59. /*------------------------增益为128,通道0----------------------------------------*/
  60. WriteByteToAd7799(0x10); //写通信寄存器设置下一个操作为写配置寄存器

  62. WriteByteToAd7799(0x37); //增益为128

  64. WriteByteToAd7799(0x30); //通道0

  66. /*------------------- 写模式寄存器初始化零值校准------------------------------------*/
  67. WriteByteToAd7799(0x08); //写通信寄存器设置下一个操作为写模式寄存器

  69. WriteByteToAd7799(0x80);

  71. WriteByteToAd7799(0x0A);

  73. WaiteRDY(); //Wait for RDY pin to Go low to indicate end of calibration cycle*/
  74. /*------------------写模式寄存器初始化全值校准-------------------------------------*/
  75. WriteByteToAd7799(0x08); //写通信寄存器设置下一个操作为写模式寄存器

  77. WriteByteToAd7799(0xA0);

  79. WriteByteToAd7799(0x0A);

  81. WaiteRDY(); // Wait for RDY pin to go low to indicate end of calibration cycle
  82. /*------------------模式0,Continuous-Conversion Mode,Fadc=16.7HZ------------------*/
  83. WriteByteToAd7799(0x08); //写通信寄存器设置下一个操作为写模式寄存器

  85. WriteByteToAd7799(0x00);

  87. WriteByteToAd7799(0x0A);

  89. }
  90. unsigned long ReadAd7799ConversionData(void)
  91. {
  92. unsigned long ConverData;
  93. unsigned char ADSAT ;
  94. unsigned char ErrNUM=0;
  95. WaiteRDY();

  97. WriteByteToAd7799(0x40); //写通信寄存器设置下一个操作为读状态STATUS寄存器

  99. WriteByteToAd7799(0xff); //伪写通信寄存器，为读状态寄存器提供时钟

  101. ADSAT=SPDAT; //读取接收到的数据
  102. while((ADSAT&0x40)||(!(ADSAT&0x08))) //出错或者读写异常
  103. {
  104. //reset ad7799
  105. WriteByteToAd7799(0xff);

  107. WriteByteToAd7799(0xff);
  108. /*----------防止时序混乱，重新同步----------*/
  109. WriteByteToAd7799(0xff);

  111. WriteByteToAd7799(0xff);

  113. //-------------------------------------------------------------------------------------
  114. AD7799_init();

  116. WaiteRDY();
  117. WriteByteToAd7799(0x40); //写通信寄存器设置下一个操作为读状态STATUS寄存器

  119. WriteByteToAd7799(0xff); //伪写通信寄存器，为读状态寄存器提供时钟

  121. ADSAT=SPDAT; //读取接收到的数据

  123. ErrNUM++;
  124. if(ErrNUM>5)break;
  125. }

  127. WriteByteToAd7799(0x58); //写通信寄存器设置下一个操作为连续读数据寄存器

  129. WaiteRDY();
  130. /* Wait for RDY pin to go low to indicate end of calibration cycle*/
  131. if(!AD7799_RDY)
  132. {
  133. ConverData=0 ;
  134. /*-----------------Read Conversion Result from AD7799's Data Register----------------*/

  136. WriteByteToAd7799(0xff); //伪写通信寄存器，为读数据寄存器寄存器提供时钟
  137. ConverData=SPDAT;
  138. ConverData=ConverData<<8 ;

  140. WriteByteToAd7799(0xff); //伪写通信寄存器，为读数据寄存器寄存器提供时钟
  141. ConverData=ConverData+SPDAT;
  142. ConverData=ConverData<<8 ;

  144. WriteByteToAd7799(0xff); //伪写通信寄存器，为读数据寄存器寄存器提供时钟
  145. ConverData=ConverData+SPDAT;

  147. }
  148. if(ErrNUM>5)return(0);
  149. else return(ConverData);
  150. }
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