[EVAL-WSN]操作系统篇——Contiki最简单的实例

dvd1478

1、前言
    Contiki是一款小型开源，易于移植的多任务操作系统，专门为无线传感网设计，适合内存受限制的网络系统。
    由于Contiki需要适应多种平台 ，所以一般的驱动分为抽像接口和具体实现两部分。

    上一篇分析了Contiki的移植过程

[EVAL-WSN]操作系统篇——Contiki移植分析https://www.cirmall.com/bbs/forum.php?mod=viewthread&tid=46002&fromuid=23447

这里做个实例有个感观认识

2、代码分析   
   以最简单的led驱动为例：
    Contiki的led驱动可简单分为抽象接口和具体实现两部分
    LED 属于外设备，抽像接口一般在 contiki-2.5\core\dev\目录下，具体实现contiki-2.5\cpu\目录下(一般以-arch结尾)
2.2）抽像接口
leds.h

1. /**
   
2. * \defgroup leds LEDs API
   
3. *
   
4. * The LEDs API defines a set of functions for accessing LEDs for
   
5. * Contiki plaforms with LEDs.
   
6. *
   
7. * A platform with LED support must implement this API.
   
8. * @{
   
9. */
   
10. 
    
11. #ifndef __LEDS_H__
    
12. #define __LEDS_H__
    
13. 
    
14. void leds_init(void);
    
15. 
    
16. /**
    
17. * Blink all LEDs.
    
18. */
    
19. void leds_blink(void);
    
20. 
    
21. /*ledv 进行位设置  有且仅有以下四种可能
    
22. 0x01 0x02 0x04 0x08 0x10 0x20 0x40 0x80
    
23. unsigned char leds_arch_get(void)
    
24. 等等，定义了 unsigned char = 8bit
    
25. 当修改即可以
    
26. */
    
27. #ifndef LEDS_GREEN
    
28. #define LEDS_GREEN  1
    
29. #endif /* LEDS_GREEN */
    
30. #ifndef LEDS_YELLOW
    
31. #define LEDS_YELLOW  2
    
32. #endif /* LEDS_YELLOW */
    
33. #ifndef LEDS_RED
    
34. #define LEDS_RED  4
    
35. #endif /* LEDS_RED */
    
36. #ifndef LEDS_BLUE
    
37. #define LEDS_BLUE  LEDS_YELLOW
    
38. #endif /* LEDS_BLUE */
    
39. 
    
40. #ifdef LEDS_CONF_ALL
    
41. #define LEDS_ALL    LEDS_CONF_ALL
    
42. #else /* LEDS_CONF_ALL */
    
43. #define LEDS_ALL    7
    
44. #endif /* LEDS_CONF_ALL */
    
45. 
    
46. /**
    
47. * Returns the current status of all leds (respects invert)
    
48. */
    
49. unsigned char leds_get(void);
    
50. void leds_on(unsigned char leds);
    
51. void leds_off(unsigned char leds);
    
52. void leds_toggle(unsigned char leds);
    
53. void leds_invert(unsigned char leds);
    
54. 
    
55. /**
    
56. * Leds implementation 具体实现
    
57. */
    
58. void leds_arch_init(void);
    
59. unsigned char leds_arch_get(void);
    
60. void leds_arch_set(unsigned char leds);
    
61. 
    
62. #endif /* __LEDS_H__ */

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leds.c

1. #include "dev/leds.h"
   
2. #include "sys/clock.h"
   
3. #include "sys/energest.h"
   
4. 
   
5. static unsigned char leds, invert;
   
6. /*---------------------------------------------------------------------------*/
   
7. static void
   
8. show_leds(unsigned char changed)
   
9. {
   
10.   if(changed & LEDS_GREEN) {
    
11.     /* Green did change */
    
12.     if((invert ^ leds) & LEDS_GREEN) {
    
13.       ENERGEST_ON(ENERGEST_TYPE_LED_GREEN);//方便跟踪节能设计了energest模块
    
14.     } else {
    
15.       ENERGEST_OFF(ENERGEST_TYPE_LED_GREEN);
    
16.     }
    
17.   }
    
18.   if(changed & LEDS_YELLOW) {
    
19.     if((invert ^ leds) & LEDS_YELLOW) {
    
20.       ENERGEST_ON(ENERGEST_TYPE_LED_YELLOW);
    
21.     } else {
    
22.       ENERGEST_OFF(ENERGEST_TYPE_LED_YELLOW);
    
23.     }
    
24.   }
    
25.   if(changed & LEDS_RED) {
    
26.     if((invert ^ leds) & LEDS_RED) {
    
27.       ENERGEST_ON(ENERGEST_TYPE_LED_RED);
    
28.     } else {
    
29.       ENERGEST_OFF(ENERGEST_TYPE_LED_RED);
    
30.     }
    
31.   }
    
32.   leds_arch_set(leds ^ invert);
    
33. }
    
34. /*---------------------------------------------------------------------------*/
    
35. void
    
36. leds_init(void)
    
37. {
    
38.   leds_arch_init();
    
39.   leds = invert = 0;
    
40. }
    
41. /*---------------------------------------------------------------------------*/
    
42. void
    
43. leds_blink(void)
    
44. {
    
45.   /* Blink all leds. */
    
46.   unsigned char inv;
    
47.   inv = ~(leds ^ invert);
    
48.   leds_invert(inv);
    
49. 
    
50.   clock_delay(400);
    
51. 
    
52.   leds_invert(inv);
    
53. }
    
54. /*---------------------------------------------------------------------------*/
    
55. unsigned char
    
56. leds_get(void) {
    
57.   return leds_arch_get();
    
58. }
    
59. /*---------------------------------------------------------------------------*/
    
60. void
    
61. leds_on(unsigned char ledv)
    
62. {
    
63.   unsigned char changed;
    
64.   changed = (~leds) & ledv;
    
65.   leds |= ledv;
    
66.   show_leds(changed);
    
67. }
    
68. /*---------------------------------------------------------------------------*/
    
69. void
    
70. leds_off(unsigned char ledv)
    
71. {
    
72.   unsigned char changed;
    
73.   changed = leds & ledv;
    
74.   leds &= ~ledv;
    
75.   show_leds(changed);
    
76. }
    
77. /*---------------------------------------------------------------------------*/
    
78. void
    
79. leds_toggle(unsigned char ledv)
    
80. {
    
81.   leds_invert(ledv);
    
82. }
    
83. /*---------------------------------------------------------------------------*/
    
84. /*   invert the invert register using the leds parameter */
    
85. void
    
86. leds_invert(unsigned char ledv) {
    
87.   invert = invert ^ ledv;
    
88.   show_leds(ledv);
    
89. }
    
90. /*---------------------------------------------------------------------------*/

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在面对用户层时只调用
void leds_init(void);

void leds_blink(void);

unsigned char leds_get(void);

void leds_on(unsigned char leds);

void leds_off(unsigned char leds);

void leds_toggle(unsigned char leds);

void leds_invert(unsigned char leds);

这么多函数公点在于调用show_leds函数

除屏蔽硬件层的影响外，还有一个更重要的意义就是进行跟踪节能统计与优化（energest模块的功能）

    2.2）具体实现部分
contiki-2.5\cpu\arm\aducrf101\leds-arch.c
contiki提供了控制LED的三大接口，分别是：

    void leds_arch_init(void)    LED初始化函数
    unsigned char leds_arch_get(void) LED状态获取函数
    void leds_arch_set(unsigned char leds)    LED状态设置函数
     各LED状态按位排列，例如最低位为LED1的状态，最低位为1则LED点亮，最低位为0则LED熄灭。以此类推。

1. #include "contiki-conf.h"
   
2. #include "dev/leds.h"
   
3. #include "device.h"
   
4. #include "gpio.h"
   
5. 
   
6. 
   
7. #define LED_ARCH_RED   GPIO_LED_RED  //P1.2
   
8. #define LED_ARCH_GREEN GPIO_LED_GREEN //P4.2
   
9. #define LED_ARCH_BLUE  GPIO_LED_BLUE  //P4.0
   
10. 
    
11. void leds_arch_init(void)
    
12. {
    
13.     //pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON1_GPIO | GP4CON_CON2_GPIO | GP4CON_CON3_GPIO;
    
14.     //pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN1_OUT | GP4OEN_OEN2_OUT | GP4OEN_OEN3_OUT;
    
15.     //pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET1_SET | GP4SET_SET2_SET | GP4SET_SET3_SET;
    
16.     pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON2_GPIO ;
    
17.     pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN2_OUT ;
    
18.     pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET2_SET ;
    
19.    
    
20.     // For RED LED on BUNCH Rev-A
    
21.     pADI_GP1->GPCON |= GP1CON_CON2_GPIO;
    
22.     pADI_GP1->GPOEN |= GP1OEN_OEN2_OUT;
    
23.     pADI_GP1->GPCLR |= GP1CLR_CLR2_CLR;
    
24. }
    
25. 
    
26. unsigned char leds_arch_get(void)
    
27. {
    
28. 
    
29. return ((pADI_GP1->GPOUT & GP1OUT_OUT2) ? 0 : LEDS_RED)
    
30. | ((pADI_GP4->GPOUT & GP4OUT_OUT2) ? 0 : LEDS_GREEN)
    
31. | ((pADI_GP4->GPOUT &GP1OUT_OUT0) ? 0 : LEDS_BLUE);
    
32. 
    
33. }
    
34. 
    
35. void leds_arch_set(unsigned char leds)
    
36. {
    
37. if(leds & LEDS_RED)   { pADI_GP1->GPCLR |= GP1CLR_CLR2; } else { pADI_GP1->GPSET |= GP1SET_SET2_SET; }
    
38. if(leds & LEDS_GREEN) { pADI_GP4->GPCLR |= GP4CLR_CLR2; } else { pADI_GP4->GPSET |= GP4SET_SET2_SET; }
    
39. if(leds & LEDS_BLUE)  { pADI_GP4->GPCLR |= GP4CLR_CLR0; } else { pADI_GP4->GPSET |= GP4SET_SET0_SET; }  
    
40. }#include "contiki-conf.h"
    
41. #include "dev/leds.h"
    
42. #include "device.h"
    
43. #include "gpio.h"
    
44. 
    
45. 
    
46. #define LED_ARCH_RED   GPIO_LED_RED  //P1.2
    
47. #define LED_ARCH_GREEN GPIO_LED_GREEN //P4.2
    
48. #define LED_ARCH_BLUE  GPIO_LED_BLUE  //P4.0
    
49. 
    
50. void leds_arch_init(void)
    
51. {
    
52.     //pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON1_GPIO | GP4CON_CON2_GPIO | GP4CON_CON3_GPIO;
    
53.     //pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN1_OUT | GP4OEN_OEN2_OUT | GP4OEN_OEN3_OUT;
    
54.     //pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET1_SET | GP4SET_SET2_SET | GP4SET_SET3_SET;
    
55.     pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON2_GPIO ;
    
56.     pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN2_OUT ;
    
57.     pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET2_SET ;
    
58.    
    
59.     // For RED LED on BUNCH Rev-A
    
60.     pADI_GP1->GPCON |= GP1CON_CON2_GPIO;
    
61.     pADI_GP1->GPOEN |= GP1OEN_OEN2_OUT;
    
62.     pADI_GP1->GPCLR |= GP1CLR_CLR2_CLR;
    
63. }
    
64. 
    
65. unsigned char leds_arch_get(void)
    
66. {
    
67. 
    
68. return ((pADI_GP1->GPOUT & GP1OUT_OUT2) ? 0 : LEDS_RED)
    
69. | ((pADI_GP4->GPOUT & GP4OUT_OUT2) ? 0 : LEDS_GREEN)
    
70. | ((pADI_GP4->GPOUT &GP1OUT_OUT0) ? 0 : LEDS_BLUE);
    
71. 
    
72. }
    
73. 
    
74. void leds_arch_set(unsigned char leds)
    
75. {
    
76. if(leds & LEDS_RED)   { pADI_GP1->GPCLR |= GP1CLR_CLR2; } else { pADI_GP1->GPSET |= GP1SET_SET2_SET; }
    
77. if(leds & LEDS_GREEN) { pADI_GP4->GPCLR |= GP4CLR_CLR2; } else { pADI_GP4->GPSET |= GP4SET_SET2_SET; }
    
78. if(leds & LEDS_BLUE)  { pADI_GP4->GPCLR |= GP4CLR_CLR0; } else { pADI_GP4->GPSET |= GP4SET_SET0_SET; }  
    
79. }
    

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   2.3) leds应用函数

1. #include "contiki.h"
   
2. #include "dev/leds.h"
   
3. /*---------------------------------------------------------------------------*/
   
4. PROCESS(test_etimer_process, "Test ET");
   
5. AUTOSTART_PROCESSES(&test_etimer_process);
   
6. /*---------------------------------------------------------------------------*/
   
7. PROCESS_THREAD(test_etimer_process, ev, data)
   
8. {
   
9.   static struct etimer et;  
   
10.   PROCESS_BEGIN();  
    
11.   while(1) {  
    
12.     etimer_set(&et, CLOCK_SECOND);                    // etimer溢出周期为1s  
    
13.     PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));  
    
14.     leds_on(LEDS_GREEN);                               // 打开LEDS_GREEN
    
15.     etimer_set(&et, CLOCK_SECOND);  
    
16.     PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));  
    
17.     leds_off(LEDS_GREEN);  
    
18.   }  
    
19.   
    
20.   PROCESS_END();
    
21. }
    
22. /*---------------------------------------------------------------------------*/

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2.4)最简单的main函数

1. int main(void)
   
2. {
   
3.     init_hw();/*硬件初始化 与 Contiki无关*/
   
4.     /*外设设备初始化*/
   
5.     leds_init();
   
6.     /* Clock */
   
7.     clock_init();
   
8.     /* Initialize process subsystem */
   
9.     process_init();
   
10.     /* etimers must be started before ctimer_init */
    
11.     process_start(&etimer_process, NULL);//设置etimer_process 进程
    
12.     ctimer_init();//设置ctimer_process 进程
    
13.    
    
14.     /* 默认程序 */
    
15.     autostart_start(autostart_processes);
    
16.     while(1) {
    
17.         process_run();
    
18.     }
    
19. }

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3、总结


这时看到闪灯的效果，有人做个闪灯有没有必要做得这么复杂，做闪灯并不是重要的目的，重要的目的是为也了解Contiki的运行机制，了解Contiki的外设的开发流程

woaidabaobao

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