51 IO口模拟串口通讯C源程序 串口, 通讯, 程序, 模拟

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1. #include <reg51.h>
   
2. sbit BT_SND =P1^0;
   
3. sbit BT_REC =P1^1;
   
4. /**********************************************
   
5. 
   
6. IO 口模拟232通讯程序
   
7. 
   
8. 使用两种方式的C程序 占用定时器0
   
9. 
   
10. **********************************************/
    
11. 
    
12. #define MODE_QUICK
    
13. 
    
14. #define F_TM F0
    
15. 
    
16. #define TIMER0_ENABLE TL0=TH0; TR0=1;
    
17. #define TIMER0_DISABLE TR0=0;
    
18. 
    
19. sbit ACC0= ACC^0;
    
20. sbit ACC1= ACC^1;
    
21. sbit ACC2= ACC^2;
    
22. sbit ACC3= ACC^3;
    
23. sbit ACC4= ACC^4;
    
24. sbit ACC5= ACC^5;
    
25. sbit ACC6= ACC^6;
    
26. sbit ACC7= ACC^7;
    
27. 
    
28. void IntTimer0() interrupt 1
    
29. {
    
30. F_TM=1;
    
31. }
    
32. //发送一个字符
    
33. void PSendChar(unsigned char inch)
    
34. {
    
35. #ifdef MODE_QUICK
    
36. ACC=inch;
    
37. 
    
38. F_TM=0;
    
39. BT_SND=0; //start bit
    
40. TIMER0_ENABLE; //启动
    
41. while(!F_TM);
    
42. 
    
43. BT_SND=ACC0; //先送出低位
    
44. F_TM=0;
    
45. while(!F_TM);
    
46. 
    
47. BT_SND=ACC1;
    
48. F_TM=0;
    
49. while(!F_TM);
    
50. 
    
51. BT_SND=ACC2;
    
52. F_TM=0;
    
53. while(!F_TM);
    
54. 
    
55. BT_SND=ACC3;
    
56. F_TM=0;
    
57. while(!F_TM);
    
58. 
    
59. BT_SND=ACC4;
    
60. F_TM=0;
    
61. while(!F_TM);
    
62. 
    
63. BT_SND=ACC5;
    
64. F_TM=0;
    
65. while(!F_TM);
    
66. 
    
67. BT_SND=ACC6;
    
68. F_TM=0;
    
69. while(!F_TM);
    
70. 
    
71. BT_SND=ACC7;
    
72. F_TM=0;
    
73. while(!F_TM);
    
74. 
    
75. BT_SND=1;
    
76. F_TM=0;
    
77. while(!F_TM);
    
78. 
    
79. 
    
80. TIMER0_DISABLE; //停止timer
    
81. #else
    
82. unsigned char ii;
    
83. 
    
84. ii=0;
    
85. 
    
86. F_TM=0;
    
87. BT_SND=0; //start bit
    
88. TIMER0_ENABLE; //启动
    
89. while(!F_TM);
    
90. 
    
91. while(ii<8)
    
92. {
    
93. if(inch&1)
    
94. {
    
95. BT_SND=1;
    
96. }
    
97. else
    
98. {
    
99. BT_SND=0;
    
100. }
     
101. F_TM=0;
     
102. while(!F_TM);
     
103. ii++;
     
104. inch>>=1;
     
105. }
     
106. BT_SND=1;
     
107. F_TM=0;
     
108. while(!F_TM);
     
109. 
     
110. #endif
     
111. TIMER0_DISABLE; //停止timer
     
112. }
     
113. //接收一个字符
     
114. unsigned char PGetChar()
     
115. {
     
116. #ifdef MODE_QUICK
     
117. 
     
118. TIMER0_ENABLE;
     
119. F_TM=0;
     
120. while(!F_TM); //等过起始位
     
121. ACC0=BT_REC;
     
122. 
     
123. TL0=TH0;
     
124. 
     
125. F_TM=0;
     
126. while(!F_TM);
     
127. ACC1=BT_REC;
     
128. 
     
129. F_TM=0;
     
130. while(!F_TM);
     
131. ACC2=BT_REC;
     
132. 
     
133. F_TM=0;
     
134. while(!F_TM);
     
135. ACC3=BT_REC;
     
136. 
     
137. F_TM=0;
     
138. while(!F_TM);
     
139. ACC4=BT_REC;
     
140. 
     
141. F_TM=0;
     
142. while(!F_TM);
     
143. ACC5=BT_REC;
     
144. 
     
145. F_TM=0;
     
146. while(!F_TM);
     
147. ACC6=BT_REC;
     
148. 
     
149. F_TM=0;
     
150. while(!F_TM);
     
151. ACC7=BT_REC;
     
152. 
     
153. F_TM=0;
     
154. 
     
155. while(!F_TM)
     
156. {
     
157. if(BT_REC)
     
158. {
     
159. break;
     
160. }
     
161. }
     
162. TIMER0_DISABLE; //停止timer
     
163. return ACC;
     
164. #else
     
165. unsigned char rch,ii;
     
166. TIMER0_ENABLE;
     
167. F_TM=0;
     
168. ii=0;
     
169. rch=0;
     
170. while(!F_TM); //等过起始位
     
171. 
     
172. while(ii<8)
     
173. {
     
174. rch>>=1;
     
175. if(BT_REC)
     
176. {
     
177. rch|=0x80;
     
178. }
     
179. ii++;
     
180. F_TM=0;
     
181. while(!F_TM);
     
182. 
     
183. }
     
184. F_TM=0;
     
185. while(!F_TM)
     
186. {
     
187. if(BT_REC)
     
188. {
     
189. break;
     
190. }
     
191. 
     
192. }
     
193. TIMER0_DISABLE; //停止timer
     
194. return rch;
     
195. 
     
196. #endif
     
197. 
     
198. }
     
199. //检查是不是有起始位
     
200. bit StartBitOn()
     
201. {
     
202. return (BT_REC==0);
     
203. 
     
204. }
     
205. void main()
     
206. {
     
207. unsigned char gch;
     
208. 
     
209. TMOD=0x22; /*定时器1为工作模式2(8位自动重装)，0为模式2(8位
     
210. 自动重装) */
     
211. PCON=00;
     
212. 
     
213. TR0=0; //在发送或接收才开始使用
     
214. TF0=0;
     
215. TH0=(256-96); //9600bps 就是 1000000/9600=104.167微秒 执行的
     
216. timer是
     
217. //
     
218. 104.167*11.0592/12= 96
     
219. TL0=TH0;
     
220. ET0=1;
     
221. EA=1;
     
222. 
     
223. PSendChar(0x55);
     
224. PSendChar(0xaa);
     
225. PSendChar(0x00);
     
226. PSendChar(0xff);
     
227. 
     
228. while(1)
     
229. {
     
230. if(StartBitOn())
     
231. {
     
232. gch=PGetChar();
     
233. PSendChar(gch);
     
234. }
     
235. }
     
236. 
     
237. }

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