【LPC800项目】代码分享:I2C驱动.

andrewz

这个I2C程序是用于L3GD20的.
在寄存器位置的第一个bit那里有特殊设置.
而且寄存器长度也仅为1个byte.
用于其他外围设备时,修改一下就OK了.
总共三个函数.

1. #include "./bsp/peripheral/i2c_hw.h"
   
2. #include "./bsp/peripheral/gpio.h"
   
3. 
   
4. #define SYSCON_SYSAHBCLKCTRL_I2C0       ((unsigned long)1<<5)
   
5. #define SYSCON_SYSAHBCLKCTRL_SWM        ((unsigned long)1<<7)
   
6. #define SYSCON_PRESETCTRL_I2C0_RST_N    ((unsigned long)1<<6)
   
7. #define SWM_PINENABLE0_I2C0_SDA         ((unsigned long)1<<11)
   
8. #define SWM_PINENABLE0_I2C0_SCL         ((unsigned long)1<<12)
   
9. #define SYSCON_SYSAHBCLKCTRL_IOCON      ((unsigned long)1<<18)
   
10. #define I2C_CFG_MSTEN                   ((unsigned long)1<<0)
    
11. #define I2C_CFG_SLVEN                   ((unsigned long)1<<1)
    
12. #define I2C_MSTCTL_MSTSTART             ((unsigned long)1<<1)
    
13. #define I2C_MSTCTL_MSTCONTINUE          ((unsigned long)1<<0)
    
14. #define I2C_MSTCTL_MSTSTOP              ((unsigned long)1<<2)
    
15. #define I2C_STAT_MSTPENDING             ((unsigned long)1<<0)
    
16. #define I2C_STAT_MSTSTATE_MASK          ((unsigned long)14)
    
17. #define I2C_STAT_MSTSTATE_IDLE          ((unsigned long)0<<1)
    
18. #define I2C_STAT_MSTSTATE_RX            ((unsigned long)1<<1)
    
19. #define I2C_STAT_MSTSTATE_TX            ((unsigned long)2<<1)
    
20. #define I2C_STAT_MSTSTATE_NACK_ADDRESS  ((unsigned long)3<<1)
    
21. #define I2C_STAT_MSTSTATE_NACK_DATA     ((unsigned long)4<<1)
    
22. 
    
23. void I2c_init(void){
    
24.     LPC_SYSCON->SYSAHBCLKCTRL|=SYSCON_SYSAHBCLKCTRL_I2C0;
    
25.    
    
26.     LPC_SYSCON->PRESETCTRL&=~SYSCON_PRESETCTRL_I2C0_RST_N;
    
27.     LPC_SYSCON->PRESETCTRL|=SYSCON_PRESETCTRL_I2C0_RST_N;
    
28.    
    
29.     LPC_SYSCON->SYSAHBCLKCTRL|=SYSCON_SYSAHBCLKCTRL_SWM;
    
30.     LPC_SWM->PINENABLE0&=~(SWM_PINENABLE0_I2C0_SDA|SWM_PINENABLE0_I2C0_SCL);
    
31.     LPC_SYSCON->SYSAHBCLKCTRL&=~SYSCON_SYSAHBCLKCTRL_SWM;
    
32.    
    
33.     LPC_I2C0->DIV=(0);/* 30M/8 = 3.75M /4 ~= 1M.*/
    
34.    
    
35.     LPC_SYSCON->SYSAHBCLKCTRL|=SYSCON_SYSAHBCLKCTRL_IOCON;
    
36.     LPC_IOCON->PIO0_10|=0x02<<8;
    
37.     LPC_IOCON->PIO0_11|=0x02<<8;
    
38.     LPC_SYSCON->SYSAHBCLKCTRL&=~SYSCON_SYSAHBCLKCTRL_IOCON;
    
39.    
    
40.     LPC_I2C0->CFG|=I2C_CFG_MSTEN;
    
41.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTOP;
    
42. }
    
43. 
    
44. unsigned char I2c_set(
    
45.     unsigned char slave,
    
46.     unsigned short reg,
    
47.     unsigned char *i_buf,
    
48.     unsigned char size
    
49. ){
    
50.     unsigned char i;
    
51.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
52.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_IDLE);/*wait master to be idle.*/
    
53.     LPC_I2C0->MSTDAT=(slave<<1);/*address with 0, write.*/
    
54.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTART;/*start the transaction.*/
    
55.    
    
56.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
57.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_TX);/*wait the address to be ACK'd.*/
    
58.     if(size!=1){
    
59.         reg|=0x80;
    
60.     }
    
61.     LPC_I2C0->MSTDAT=(reg&0xFF);
    
62.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTCONTINUE;
    
63.    
    
64.     for(i=0;i<size;i++){
    
65.         while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
66.         while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_TX);
    
67.         LPC_I2C0->MSTDAT=(*i_buf++);
    
68.         LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTCONTINUE;
    
69.     }
    
70.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
71.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_TX);
    
72.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTOP;
    
73.     return(0);
    
74. }
    
75. 
    
76. 
    
77. unsigned char I2c_get(
    
78.     unsigned char slave,
    
79.     unsigned short reg,
    
80.     unsigned char *o_buf,
    
81.     unsigned char size
    
82. ){
    
83.     unsigned char i;
    
84.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
85.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_IDLE);/*wait master to be idle.*/
    
86.     LPC_I2C0->MSTDAT=(slave<<1);/*address with 0, write.*/
    
87.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTART;/*start the transaction.*/
    
88.    
    
89.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
90.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_TX);/*wait the address to be ACK'd.*/
    
91.     if(size!=1){
    
92.         reg|=0x80;
    
93.     }
    
94.     LPC_I2C0->MSTDAT=(reg&0xFF);
    
95.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTCONTINUE;
    
96.    
    
97.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
    
98.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_TX);/*wait the address to be ACK'd.*/
    
99.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTOP;
    
100.    
     
101.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
     
102.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_IDLE);/*wait master to be idle.*/
     
103.     LPC_I2C0->MSTDAT=((slave<<1)|(unsigned char)1);
     
104.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTART;
     
105. 
     
106.     for(i=0;i<size;i++){
     
107.         while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
     
108.         while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_RX);/*wait the address to be ACK'd.*/
     
109.         *o_buf++=LPC_I2C0->MSTDAT;
     
110.         LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTCONTINUE;
     
111.     }
     
112.     while((LPC_I2C0->STAT&I2C_STAT_MSTPENDING)==0);
     
113.     while((LPC_I2C0->STAT&I2C_STAT_MSTSTATE_MASK)!=I2C_STAT_MSTSTATE_RX);
     
114.     LPC_I2C0->MSTCTL=I2C_MSTCTL_MSTSTOP;
     
115. 
     
116.     return(0);
     
117. }
     
118. 
     

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有疑问或者改进欢迎跟贴~

阅读全文

aoxiangwode2008

很好 学习了。。。

lkl0305

学习了

ωо決吥倣棄

还是只会点LED灯

caoren123

看一哈不错！！！

andrewz

ωо決吥倣棄 发表于 2016-12-11 20:29
还是只会点LED灯

会点灯已经很不错了~