I2C

Revision:
0:b88f2b54dc27
diff -r 000000000000 -r b88f2b54dc27 I2C.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2C.c	Sat Oct 14 13:57:22 2017 +0000
@@ -0,0 +1,210 @@
+#include "I2C.h"
+#include"mbed.h"
+
+void Delay(u32 count){while (count--);}
+void SDA_IN(){sda.input();}
+void SDA_OUT(){sda.output();}
+void IIC_SCL(int a = 0){scl.write(a);}
+void IIC_SDA(int a = 0){sda.write(a);}
+int READ_SDA(){return sda.read();}
+void IIC_Init()
+{    
+    SDA.mode(OpenDrain);
+    SCL.mode(OpenDrain);        
+    SDA_OUT();
+    IIC_SDA(1);        
+    IIC_SCL(1);
+}
+void IIC_Start(void)
+{
+    SDA_OUT();     //sdaÏßÊä³ö
+    IIC_SDA();        
+    IIC_SCL();
+    
+    Delay(5);
+    IIC_SDA(0);//START:when CLK is high,DATA change form high to low 
+    
+    Delay(5);
+    IIC_SCL(0);//ǯסI2C×ÜÏߣ¬×¼±¸·¢ËÍ»ò½ÓÊÕÊý¾Ý 
+}
+
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      void IIC_Stop(void)
+*¹¦¡¡¡¡ÄÜ:      //²úÉúIICÍ£Ö¹ÐźÅ
+*******************************************************************************/      
+void IIC_Stop(void)
+{
+    SDA_OUT();//sdaÏßÊä³ö
+    IIC_SCL(0);
+    IIC_SDA(0);//STOP:when CLK is high DATA change form low to high
+    
+        Delay(5);
+    IIC_SCL(1); 
+    IIC_SDA(1);//·¢ËÍI2C×ÜÏß½áÊøÐźÅ
+    
+        Delay(5);                               
+}
+
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      unsigned char IIC_Wait_Ack(void)
+*¹¦¡¡¡¡ÄÜ:      µÈ´ýÓ¦´ðÐźŵ½À´ 
+//·µ»ØÖµ£º1£¬½ÓÊÕÓ¦´ðʧ°Ü
+//        0£¬½ÓÊÕÓ¦´ð³É¹¦
+*******************************************************************************/
+unsigned char IIC_Wait_Ack(void)
+{
+    unsigned char ucErrTime=0; 
+    SDA_IN();      //SDAÉèÖÃΪÊäÈë  
+    IIC_SDA(1);
+        Delay(5);     
+    while(READ_SDA)
+    {
+        ucErrTime++;
+        if(ucErrTime>50)
+        {
+            IIC_Stop();
+            return 1;
+        }
+        Delay(5);
+    }  
+    IIC_SCL(1);
+    Delay(5); 
+    IIC_SCL(0);//ʱÖÓÊä³ö0  
+    return 0;  
+} 
+
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      void IIC_Ack(void)
+*¹¦¡¡¡¡ÄÜ:      ²úÉúACKÓ¦´ð
+*******************************************************************************/
+void IIC_Ack(void)
+{
+    IIC_SCL(0);
+    SDA_OUT();
+    IIC_SDA(0);
+        Delay(5);
+    IIC_SCL(1);
+        Delay(5);
+    IIC_SCL(0);
+}
+    
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      void IIC_NAck(void)
+*¹¦¡¡¡¡ÄÜ:      ²úÉúNACKÓ¦´ð
+*******************************************************************************/        
+void IIC_NAck(void)
+{
+    IIC_SCL(0);
+    SDA_OUT();
+    IIC_SDA(0);
+    
+        Delay(5);
+    IIC_SCL(1);
+        Delay(5);
+    IIC_SCL(1);
+}                                        
+
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      void IIC_Send_Byte(unsigned char txd)
+*¹¦¡¡¡¡ÄÜ:      IIC·¢ËÍÒ»¸ö×Ö½Ú
+*******************************************************************************/          
+void IIC_Send_Byte(unsigned char txd)
+{                        
+    unsigned char t; 
+        SDA_OUT();      
+    IIC_SCL(0);//À­µÍʱÖÓ¿ªÊ¼Êý¾Ý´«Êä
+    for(t=0;t<8;t++)
+    {              
+        IIC_SDA=(txd&0x80)>>7;
+        txd<<=1;      
+            
+        Delay(2);   
+        IIC_SCL(1);
+        Delay(5);
+        IIC_SCL(0);  
+        Delay(3);
+    }    
+}    
+   
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      unsigned char IIC_Read_Byte(unsigned char ack)
+*¹¦¡¡¡¡ÄÜ:      //¶Á1¸ö×Ö½Ú£¬ack=1ʱ£¬·¢ËÍACK£¬ack=0£¬·¢ËÍnACK 
+*******************************************************************************/  
+unsigned char IIC_Read_Byte(unsigned char ack)
+{
+    unsigned char i,receive=0;
+    SDA_IN();//SDAÉèÖÃΪÊäÈë
+    for(i=0;i<8;i++ )
+    {
+        IIC_SCL(0); 
+        
+        Delay(5);
+        IIC_SCL(1);
+        receive<<=1;
+        if(READ_SDA)receive++;   
+        
+        Delay(5); 
+    }                    
+    if (ack)
+        IIC_Ack(); //·¢ËÍACK 
+    else
+        IIC_NAck();//·¢ËÍnACK  
+    return receive;
+}
+
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      unsigned char IICreadBytes(unsigned char dev, unsigned char reg, unsigned char length, unsigned char *data)
+*¹¦¡¡¡¡ÄÜ:      ¶ÁÈ¡Ö¸¶¨É豸 Ö¸¶¨¼Ä´æÆ÷µÄ length¸öÖµ
+ÊäÈë    dev  Ä¿±êÉ豸µØÖ·
+        reg   ¼Ä´æÆ÷µØÖ·
+        length Òª¶ÁµÄ×Ö½ÚÊý
+        *data  ¶Á³öµÄÊý¾Ý½«Òª´æ·ÅµÄÖ¸Õë
+·µ»Ø   ¶Á³öÀ´µÄ×Ö½ÚÊýÁ¿
+*******************************************************************************/ 
+unsigned char IICreadBytes(unsigned char dev, unsigned char reg, unsigned char length, unsigned char *data){
+    unsigned char count = 0;
+    
+    IIC_Start();
+    IIC_Send_Byte(dev<<1);     //·¢ËÍдÃüÁî
+    IIC_Wait_Ack();
+    IIC_Send_Byte(reg);   //·¢Ë͵ØÖ·
+  IIC_Wait_Ack();     
+    IIC_Start();
+    IIC_Send_Byte((dev<<1)+1);  //½øÈë½ÓÊÕģʽ  
+    IIC_Wait_Ack();
+    
+    for(count=0;count<length;count++){
+         
+         if(count!=length-1)data[count]=IIC_Read_Byte(1);  //´øACKµÄ¶ÁÊý¾Ý
+            else  data[count]=IIC_Read_Byte(0);  //×îºóÒ»¸ö×Ö½ÚNACK
+    }
+    IIC_Stop();//²úÉúÒ»¸öÍ£Ö¹Ìõ¼þ
+    return count;
+}
+
+/**************************ʵÏÖº¯Êý********************************************
+*º¯ÊýÔ­ÐÍ:      unsigned char IICwriteBytes(unsigned char dev, unsigned char reg, unsigned char length, unsigned char* data)
+*¹¦¡¡¡¡ÄÜ:      ½«¶à¸ö×Ö½ÚдÈëÖ¸¶¨É豸 Ö¸¶¨¼Ä´æÆ÷
+ÊäÈë    dev  Ä¿±êÉ豸µØÖ·
+        reg   ¼Ä´æÆ÷µØÖ·
+        length ҪдµÄ×Ö½ÚÊý
+        *data  ½«ÒªÐ´µÄÊý¾ÝµÄÊ×µØÖ·
+·µ»Ø   ·µ»ØÊÇ·ñ³É¹¦
+*******************************************************************************/ 
+unsigned char IICwriteBytes(unsigned char dev, unsigned char reg, unsigned char length, unsigned char* data){
+  
+    unsigned char count = 0;
+    IIC_Start();
+    IIC_Send_Byte(dev<<1);     //·¢ËÍдÃüÁî
+    IIC_Wait_Ack();
+    IIC_Send_Byte(reg);   //·¢Ë͵ØÖ·
+    IIC_Wait_Ack();   
+    for(count=0;count<length;count++){
+        IIC_Send_Byte(data[count]); 
+        IIC_Wait_Ack(); 
+ }
+    IIC_Stop();//²úÉúÒ»¸öÍ£Ö¹Ìõ¼þ
+
+    return 1; //status == 0;
+    
+}
\ No newline at end of file