Contiki简单的实例——led驱动

lukobe

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，链接https://www.eeboard.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

• /**
  
• * \defgroup leds LEDs API
  
• *
  
• * The LEDs API defines a set of functions for accessing LEDs for
  
• * Contiki plaforms with LEDs.
  
• *
  
• * A platform with LED support must implement this API.
  
• * @{
  
• */
  
• 
  
• #ifndef __LEDS_H__
  
• #define __LEDS_H__
  
• 
  
• void leds_init(void);
  
• 
  
• /**
  
• * Blink all LEDs.
  
• */
  
• void leds_blink(void);
  
• 
  
• /*ledv 进行位设置 有且仅有以下四种可能
  
• 0x01 0x02 0x04 0x08 0x10 0x20 0x40 0x80
  
• unsigned char leds_arch_get(void)
  
• 等等，定义了 unsigned char = 8bit
  
• 当修改即可以
  
• */
  
• #ifndef LEDS_GREEN
  
• #define LEDS_GREEN 1
  
• #endif /* LEDS_GREEN */
  
• #ifndef LEDS_YELLOW
  
• #define LEDS_YELLOW 2
  
• #endif /* LEDS_YELLOW */
  
• #ifndef LEDS_RED
  
• #define LEDS_RED 4
  
• #endif /* LEDS_RED */
  
• #ifndef LEDS_BLUE
  
• #define LEDS_BLUE LEDS_YELLOW
  
• #endif /* LEDS_BLUE */
  
• 
  
• #ifdef LEDS_CONF_ALL
  
• #define LEDS_ALL    LEDS_CONF_ALL
  
• #else /* LEDS_CONF_ALL */
  
• #define LEDS_ALL    7
  
• #endif /* LEDS_CONF_ALL */
  
• 
  
• /**
  
• * Returns the current status of all leds (respects invert)
  
• */
  
• 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);
  
• 
  
• /**
  
• * Leds implementation 具体实现
  
• */
  
• void leds_arch_init(void);
  
• unsigned char leds_arch_get(void);
  
• void leds_arch_set(unsigned char leds);
  
• 
  
• #endif /* __LEDS_H__ */
  

复制代码
leds.c

• #include "dev/leds.h"
  
• #include "sys/clock.h"
  
• #include "sys/energest.h"
  
• 
  
• static unsigned char leds, invert;
  
• /*---------------------------------------------------------------------------*/
  
• static void
  
• show_leds(unsigned char changed)
  
• {
  
• if(changed & LEDS_GREEN) {
  
•     /* Green did change */
  
•     if((invert ^ leds) & LEDS_GREEN) {
  
•      ENERGEST_ON(ENERGEST_TYPE_LED_GREEN);//方便跟踪节能设计了energest模块
  
•     } else {
  
•      ENERGEST_OFF(ENERGEST_TYPE_LED_GREEN);
  
•     }
  
• }
  
• if(changed & LEDS_YELLOW) {
  
•     if((invert ^ leds) & LEDS_YELLOW) {
  
•      ENERGEST_ON(ENERGEST_TYPE_LED_YELLOW);
  
•     } else {
  
•      ENERGEST_OFF(ENERGEST_TYPE_LED_YELLOW);
  
•     }
  
• }
  
• if(changed & LEDS_RED) {
  
•     if((invert ^ leds) & LEDS_RED) {
  
•      ENERGEST_ON(ENERGEST_TYPE_LED_RED);
  
•     } else {
  
•      ENERGEST_OFF(ENERGEST_TYPE_LED_RED);
  
•     }
  
• }
  
• leds_arch_set(leds ^ invert);
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• void
  
• leds_init(void)
  
• {
  
• leds_arch_init();
  
• leds = invert = 0;
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• void
  
• leds_blink(void)
  
• {
  
• /* Blink all leds. */
  
• unsigned char inv;
  
• inv = ~(leds ^ invert);
  
• leds_invert(inv);
  
• 
  
• clock_delay(400);
  
• 
  
• leds_invert(inv);
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• unsigned char
  
• leds_get(void) {
  
• return leds_arch_get();
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• void
  
• leds_on(unsigned char ledv)
  
• {
  
• unsigned char changed;
  
• changed = (~leds) & ledv;
  
• leds |= ledv;
  
• show_leds(changed);
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• void
  
• leds_off(unsigned char ledv)
  
• {
  
• unsigned char changed;
  
• changed = leds & ledv;
  
• leds &= ~ledv;
  
• show_leds(changed);
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• void
  
• leds_toggle(unsigned char ledv)
  
• {
  
• leds_invert(ledv);
  
• }
  
• /*---------------------------------------------------------------------------*/
  
• /*   invert the invert register using the leds parameter */
  
• void
  
• leds_invert(unsigned char ledv) {
  
• invert = invert ^ ledv;
  
• show_leds(ledv);
  
• }
  
• /*---------------------------------------------------------------------------*/
  

复制代码
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。

• #include "contiki-conf.h"
  
• #include "dev/leds.h"
  
• #include "device.h"
  
• #include "gpio.h"
  
• 
  
• 
  
• #define LED_ARCH_RED   GPIO_LED_RED //P1.2
  
• #define LED_ARCH_GREEN GPIO_LED_GREEN //P4.2
  
• #define LED_ARCH_BLUE GPIO_LED_BLUE //P4.0
  
• 
  
• void leds_arch_init(void)
  
• {
  
•     //pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON1_GPIO | GP4CON_CON2_GPIO | GP4CON_CON3_GPIO;
  
•     //pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN1_OUT | GP4OEN_OEN2_OUT | GP4OEN_OEN3_OUT;
  
•     //pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET1_SET | GP4SET_SET2_SET | GP4SET_SET3_SET;
  
•     pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON2_GPIO ;
  
•     pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN2_OUT ;
  
•     pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET2_SET ;
  
• 
  
•     // For RED LED on BUNCH Rev-A
  
•     pADI_GP1->GPCON |= GP1CON_CON2_GPIO;
  
•     pADI_GP1->GPOEN |= GP1OEN_OEN2_OUT;
  
•     pADI_GP1->GPCLR |= GP1CLR_CLR2_CLR;
  
• }
  
• 
  
• unsigned char leds_arch_get(void)
  
• {
  
• 
  
• return ((pADI_GP1->GPOUT & GP1OUT_OUT2) ? 0 : LEDS_RED)
  
• | ((pADI_GP4->GPOUT & GP4OUT_OUT2) ? 0 : LEDS_GREEN)
  
• | ((pADI_GP4->GPOUT &GP1OUT_OUT0) ? 0 : LEDS_BLUE);
  
• 
  
• }
  
• 
  
• void leds_arch_set(unsigned char leds)
  
• {
  
• if(leds & LEDS_RED)   { pADI_GP1->GPCLR |= GP1CLR_CLR2; } else { pADI_GP1->GPSET |= GP1SET_SET2_SET; }
  
• if(leds & LEDS_GREEN) { pADI_GP4->GPCLR |= GP4CLR_CLR2; } else { pADI_GP4->GPSET |= GP4SET_SET2_SET; }
  
• if(leds & LEDS_BLUE) { pADI_GP4->GPCLR |= GP4CLR_CLR0; } else { pADI_GP4->GPSET |= GP4SET_SET0_SET; }
  
• }#include "contiki-conf.h"
  
• #include "dev/leds.h"
  
• #include "device.h"
  
• #include "gpio.h"
  
• 
  
• 
  
• #define LED_ARCH_RED   GPIO_LED_RED //P1.2
  
• #define LED_ARCH_GREEN GPIO_LED_GREEN //P4.2
  
• #define LED_ARCH_BLUE GPIO_LED_BLUE //P4.0
  
• 
  
• void leds_arch_init(void)
  
• {
  
•     //pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON1_GPIO | GP4CON_CON2_GPIO | GP4CON_CON3_GPIO;
  
•     //pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN1_OUT | GP4OEN_OEN2_OUT | GP4OEN_OEN3_OUT;
  
•     //pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET1_SET | GP4SET_SET2_SET | GP4SET_SET3_SET;
  
•     pADI_GP4->GPCON |= GP4CON_CON0_GPIO | GP4CON_CON2_GPIO ;
  
•     pADI_GP4->GPOEN |= GP4OEN_OEN0_OUT | GP4OEN_OEN2_OUT ;
  
•     pADI_GP4->GPSET |= GP4SET_SET0_SET | GP4SET_SET2_SET ;
  
• 
  
•     // For RED LED on BUNCH Rev-A
  
•     pADI_GP1->GPCON |= GP1CON_CON2_GPIO;
  
•     pADI_GP1->GPOEN |= GP1OEN_OEN2_OUT;
  
•     pADI_GP1->GPCLR |= GP1CLR_CLR2_CLR;
  
• }
  
• 
  
• unsigned char leds_arch_get(void)
  
• {
  
• 
  
• return ((pADI_GP1->GPOUT & GP1OUT_OUT2) ? 0 : LEDS_RED)
  
• | ((pADI_GP4->GPOUT & GP4OUT_OUT2) ? 0 : LEDS_GREEN)
  
• | ((pADI_GP4->GPOUT &GP1OUT_OUT0) ? 0 : LEDS_BLUE);
  
• 
  
• }
  
• 
  
• void leds_arch_set(unsigned char leds)
  
• {
  
• if(leds & LEDS_RED)   { pADI_GP1->GPCLR |= GP1CLR_CLR2; } else { pADI_GP1->GPSET |= GP1SET_SET2_SET; }
  
• if(leds & LEDS_GREEN) { pADI_GP4->GPCLR |= GP4CLR_CLR2; } else { pADI_GP4->GPSET |= GP4SET_SET2_SET; }
  
• if(leds & LEDS_BLUE) { pADI_GP4->GPCLR |= GP4CLR_CLR0; } else { pADI_GP4->GPSET |= GP4SET_SET0_SET; }
  
• }
  

复制代码

    2.3) leds应用函数

• #include "contiki.h"
  
• #include "dev/leds.h"
  
• /*---------------------------------------------------------------------------*/
  
• PROCESS(test_etimer_process, "Test ET");
  
• AUTOSTART_PROCESSES(&test_etimer_process);
  
• /*---------------------------------------------------------------------------*/
  
• PROCESS_THREAD(test_etimer_process, ev, data)
  
• {
  
• static struct etimer et;
  
• PROCESS_BEGIN();
  
• while(1) {
  
•     etimer_set(&et, CLOCK_SECOND);             // etimer溢出周期为1s
  
•     PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));
  
•     leds_on(LEDS_GREEN);                      // 打开LEDS_GREEN
  
•     etimer_set(&et, CLOCK_SECOND);
  
•     PROCESS_WAIT_EVENT_UNTIL(etimer_expired(&et));
  
•     leds_off(LEDS_GREEN);
  
• }
  
• 
  
• PROCESS_END();
  
• }
  
• /*---------------------------------------------------------------------------*/
  

复制代码
2.4)最简单的main函数

• int main(void)
  
• {
  
•     init_hw();/*硬件初始化 与 Contiki无关*/
  
•     /*外设设备初始化*/
  
•     leds_init();
  
•     /* Clock */
  
•     clock_init();
  
•     /* Initialize process subsystem */
  
•     process_init();
  
•     /* etimers must be started before ctimer_init */
  
•     process_start(&etimer_process, NULL);//设置etimer_process 进程
  
•     ctimer_init();//设置ctimer_process 进程
  
• 
  
•     /* 默认程序 */
  
•     autostart_start(autostart_processes);
  
•     while(1) {
  
•      process_run();
  
•     }
  
• }
  

复制代码
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