标题: 简易18B20温度传感器并联3路温度指示程序 [打印本页]
作者: bibi    时间: 2015-4-19 02:41
标题: 简易18B20温度传感器并联3路温度指示程序










  1. #include "1602.h"
  2. #define u8 unsigned char
  3. #define u16 unsigned int
  4. sbit dq=P3^7;

  6. float t;   
  7. bit start;  
  8. u8 id[8];  

  10. u8 id1[8]={0x28,0xFE,0x27,0xFA,0x03,0x00,0x00,0x58};   
  11. u8 id2[8]={0x28,0x82,0x0F,0xC7,0x05,0x00,0x00,0x7F};
  12. u8 id3[8]={0x28,0xA1,0xC1,0xC6,0x05,0x00,0x00,0x9F};



  16. void send_0()
  17. {
  18. dq=0;
  19. delay(30);
  20. dq=1;
  21. }

  23. void send_1()
  24. {
  25. dq=0;
  26. delay(0);
  27. dq=1;
  28. delay(30);

  30. }

  32. void ds18B20_send_cmd(u8 cmd)
  33. {
  34. u8 i,d;
  35. d=cmd;
  36. for(i=0;i<8;i++)
  37. {
  38. if(d&0x01)
  39. {
  40. send_1();
  41. }
  42. else
  43. {
  44. send_0();
  45. }
  46. d>>=1;
  47. }
  48. }

  50. u8 ds18B20_receive()
  51. {
  52. u8 i,d;
  53. for(i=0;i<8;i++)
  54. {
  55. d>>=1;
  56. dq=0;
  57. delay(0);
  58. dq=1;
  59. delay(0);
  60. if(dq==1)
  61. {
  62. d|=0x80;
  63. }
  64.     delay(35);        
  65. }
  66. return d;        
  67. }


  70. u8 ds18b20_start()
  71. {
  72. u16 tt;
  73. dq=0;
  74. delay(330);
  75. dq=1;
  76. delay(30);
  77. tt=0;
  78. while(dq==1)   
  79. {
  80. tt++;
  81. if(tt>10000)
  82. {
  83. return 1;   
  84. }        
  85. }
  86. tt=0;
  87. delay(120);
  88. while(dq==0)
  89. {
  90. tt++;
  91. if(tt>10000)
  92. {
  93. return 2;   
  94. }        
  95. }
  96. return 0;
  97. }


  100. float read_n_18b20_temp(u8 *id)
  101. {
  102. u8 th,tl;

  104. u16 temp;  
  105. u8 i;
  106. start=ds18b20_start();
  107. ds18B20_send_cmd(0x55);
  108. for(i=0;i<8;i++)
  109. {
  110. ds18B20_send_cmd(id[i]);
  111. }
  112. ds18B20_send_cmd(0x44);
  113. delay(2000);
  114. start=ds18b20_start();
  115. ds18B20_send_cmd(0x55);
  116. for(i=0;i<8;i++)
  117. {
  118. ds18B20_send_cmd(id[i]);
  119. }
  120. ds18B20_send_cmd(0xbe);  
  121. tl=ds18B20_receive();
  122. th=ds18B20_receive();
  123. temp=th;
  124. temp<<=8;
  125. temp|=tl;
  126. if(temp&0x8000)  
  127. {
  128. temp=~temp+1;
  129. }
  130. t=temp*0.0625;
  131. return t;
  132. }


  135. void main()
  136. {
  137. float t1,t2,t3;  
  138. LCD_init();
  139. delay(1000);

  141. show_char(0x00,'A');
  142. show_char(0x08,'B');
  143. show_char(0x40,'C');
  144. while(1)
  145. {
  146. t1=read_n_18b20_temp(id1);
  147. t2=read_n_18b20_temp(id2);
  148. t3=read_n_18b20_temp(id3);
  149. delay(2000);
  150. show_float(0x02,t1);
  151. show_float(0x42,t2);
  152. show_float(0x0A,t3);
  153. }        
  154. }

  156. //------------------------------------------
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作者: pipilu    时间: 2015-4-19 10:42
这个可以学习，感谢楼主分享



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