Contiki简单的实例——led驱动

lukobe · 发表于 2016-2-25 09:28:49

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&mdash;&mdash;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

Contiki简单的实例——led驱动

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