1 //³õʼ»¯IIC
2 void IIC_Init(void)
3 {
4 GPIO_InitTypeDef GPIO_InitStructure;
5 RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE ); //ʹÄÜGPIOBʱÖÓ
6
7 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;
8 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP ; //ÍÆÍìÊä³ö
9 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
10 GPIO_Init(GPIOB, &GPIO_InitStructure);
11 GPIO_SetBits(GPIOB,GPIO_Pin_6|GPIO_Pin_7); //PB6,PB7 Êä³ö¸ß
12 }
13 //²úÉúIICÆðʼÐźÅ
14 void IIC_Start(void)
15 {
16 SDA_OUT(); //sdaÏßÊä³ö
17 IIC_SDA=1;
18 IIC_SCL=1;
19 delay_us(4);
20 IIC_SDA=0;//START:when CLK is high,DATA change form high to low
21 delay_us(4);
22 IIC_SCL=0;//ǯסI2C×ÜÏߣ¬×¼±¸·¢ËÍ»ò½ÓÊÕÊý¾Ý
23 }
24 //²úÉúIICÍ£Ö¹ÐźÅ
25 void IIC_Stop(void)
26 {
27 SDA_OUT();//sdaÏßÊä³ö
28 IIC_SCL=0;
29 IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
30 delay_us(4);
31 IIC_SCL=1;
32 IIC_SDA=1;//·¢ËÍI2C×ÜÏß½áÊøÐźÅ
33 delay_us(4);
34 }
35 //µÈ´ýÓ¦´ðÐźŵ½À´
36 //·µ»ØÖµ£º1£¬½ÓÊÕÓ¦´ðʧ°Ü
37 // 0£¬½ÓÊÕÓ¦´ð³É¹¦
38 u8 IIC_Wait_Ack(void)
39 {
40 u8 ucErrTime=0;
41 SDA_IN(); //SDAÉèÖÃΪÊäÈë
42 IIC_SDA=1;delay_us(1);
43 IIC_SCL=1;delay_us(1);
44 while(READ_SDA)
45 {
46 ucErrTime++;
47 if(ucErrTime>250)
48 {
49 IIC_Stop();
50 return 1;
51 }
52 }
53 IIC_SCL=0;//ʱÖÓÊä³ö0
54 return 0;
55 }
56 //²úÉúACKÓ¦´ð
57 void IIC_Ack(void)
58 {
59 IIC_SCL=0;
60 SDA_OUT();
61 IIC_SDA=0;
62 delay_us(2);
63 IIC_SCL=1;
64 delay_us(2);
65 IIC_SCL=0;
66 }
67 //²»²úÉúACKÓ¦´ð
68 void IIC_NAck(void)
69 {
70 IIC_SCL=0;
71 SDA_OUT();
72 IIC_SDA=1;
73 delay_us(2);
74 IIC_SCL=1;
75 delay_us(2);
76 IIC_SCL=0;
77 }
78 //IIC·¢ËÍÒ»¸ö×Ö½Ú
79 //·µ»Ø´Ó»úÓÐÎÞÓ¦´ð
80 //1£¬ÓÐÓ¦´ð
81 //0£&