网页控制LED （写通道形式）

来源：互联网发布：淘宝收货姓名写什么好编辑：程序博客网时间：2024/04/28 14:30

转载：http://blog.sina.com.cn/s/blog_67d069a90100plor.html

ps：不同时刻看一样的文章/搞同一个项目（网页控制led），有不同的感受；搞嵌入式的时候，关注的是：如何控制led灯亮的，想搞服务器的时候：关注的是：服务器搭建（html、gui）

首先在TQ2440开发板的/web目录下建一个目录 ledweb
所需文件：leds.html--------LED的网页文件
testleds.cgi--------作用就是一个shell文件，将网页提交的内容写到通道中去
led-result.template------提交按钮点击后出现的网页的内容由其提供，作用就是返回到leds.html
ledwebqidong文件放在 /etc/rc.d/init.d/下---------shell文件，与rcS中有关命令相结合
ledtest.c------------应用文件，通过读取管道信息，管理LED的亮灭。生成ledweb针对开发板的可执行文件。将ledweb放在开发板的/sbin下。
上面完成以后（注意权限），只需更改/etc/init.d/rcs文件，添加一句：
/etc/rc.d/init.d/ledwebqidong start
即可。
在浏览器栏中输入：
http://192.168.1.6/ledweb/leds.html就操作控制led。
%%%%%%%%%%%%%%%leds.html%%%%%%%%%%%%%%%%%%%%%%%
<head>
<meta http-equiv="Content-Language" content="zh-cn">
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<meta name="GENERATOR" content="Microsoft FrontPage 4.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<title>LED灯测试</title>

</style></head>

<body>

<h1 align="left">LED测试</h1>
<form method="get" action="testleds.cgi" name="LED-TEST">
<div align="left">
<table border="0" width="100%">
<tr>
<td width="80px">
<b> LED灯：</b>
</td>
<td width="80px">
LED1<input type="checkbox" name="cb_led" value="led1" />
</td>
<td width="80px">
LED2<input type="checkbox" name="cb_led" value="led2" />
</td>
<td width="80px">
LED3<input type="checkbox" name="cb_led" value="led3" />
</td>
<td width="80px">
LED4<input type="checkbox" name="cb_led" value="led4" />
</td>
<td></td>
</tr>


<tr>
<td width="80px">
<input type="submit" value="确定" name="submit">
</td>
<td></td>
</tr>

</table>
</div>
</form>
</body>

</html>
%%%%%%%%%%%%%%%leds.html %%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%testleds.cgi%%%%%%%%%%%%%%%%%%%%%%%
#!/bin/sh

LED1_ON=0
LED2_ON=0
LED3_ON=0
LED4_ON=0
SPEED=1

case $QUERY_STRING in
*cb_led=led1*)
LED1_ON=1
;;
esac

case $QUERY_STRING in
*cb_led=led2*)
LED2_ON=1
;;
esac

case $QUERY_STRING in
*cb_led=led3*)
LED3_ON=1
;;
esac

case $QUERY_STRING in
*cb_led=led4*)
LED4_ON=1
;;
esac

/bin/echo $LED1_ON $LED2_ON $LED3_ON $LED4_ON > /tmp/led-control

/bin/echo "Content-type: text/html; charset=gb2312"
/bin/echo
#/bin/echo $QUERY_STRING "STRING"

/bin/cat led-result.template
exit 0
%%%%%%%%%%%%%%%testleds.cgi%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%led-result.template%%%%%%%%%%%%%%%%%%%%%%%
<html>
<head>
<title>LED测试结果</title>
<style type="text/css">

</style>
</head>
<body>
<p>LED设置已经提交</p>
<p><a href="leds.html">返回上一页</a></p>
</body>
</html>
%%%%%%%%%%%%%%%led-result.template%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%ledwebqidong%%%%%%%%%%%%%%%%%%%%%%%

#!/bin/sh

base=/sbin/ledweb

# See how we were called.
case "$1" in
start)
$base &
;;
stop)
pid=`/bin/pidof $base`
if [ -n "$pid" ]; then
kill -9 $pid
fi
;;
esac

exit 0

%%%%%%%%%%%%%%%ledwebqidong%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%ledtest.c%%%%%%%%%%%%%%%%%%%%%%%

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/time.h>
#include<string.h>
static int led_fd;
static int leds[4] = {0};

static void lightleds(void)
{
int i;
for(i=0;i<4;i++)
{
ioctl(led_fd, leds[i], i);
}
}

int main(void)
{
int led_control_pipe;
int null_writer_fd; // for read endpoint not blocking when control process exit
led_fd = open("/dev/EmbedSky-leds", 0);
if (led_fd < 0) {
perror("open device leds");
exit(1);
}
unlink("/tmp/led-control");
mkfifo("/tmp/led-control", 0666);

led_control_pipe = open("/tmp/led-control", O_RDONLY | O_NONBLOCK);
if (led_control_pipe < 0) {
perror("open control pipe for read");
exit(1);
}
null_writer_fd = open("/tmp/led-control", O_WRONLY | O_NONBLOCK);
if (null_writer_fd < 0) {
perror("open control pipe for write");
exit(1);
}

for (;;) {
fd_set rds;
int ret;
struct timeval step;
step.tv_sec = 0;
step.tv_usec =0.125*1000000L;
FD_ZERO(&rds);
FD_SET(led_control_pipe, &rds);
ret = select(led_control_pipe + 1, &rds, NULL, NULL, &step);
if (ret < 0) {
perror("select");
exit(1);
}
if (ret == 0) {
lightleds();
}
else if (FD_ISSET(led_control_pipe, &rds)) {
static char buffer[200];
for (;;) {
char c;
int len = strlen(buffer);
if (len >= sizeof buffer - 1) {
memset(buffer, 0, sizeof buffer);
break;
}
if (read(led_control_pipe, &c, 1) != 1) {
break;
}
if (c == '\r') {
continue;
}
if (c == '\n') {
int tmp_leds[4];
if (sscanf(buffer,"%d%d%d%d", &tmp_leds[0], &tmp_leds[1],&tmp_leds[2],&tmp_leds[3]) == 4) {
leds[0] = tmp_leds[0];
leds[1] = tmp_leds[1];
leds[2] = tmp_leds[2];
leds[3] = tmp_leds[3];
}
int j;
for(j=0;j<4;j++)
{
if(leds[j])
fprintf(stderr,"led%d is on\n",j+1);
else
fprintf(stderr, "led%d is off\n",j+1);
}
memset(buffer, 0, sizeof buffer);
break;
}
buffer[len] = c;
}
}
}

close(led_fd);
return 0;
}
%%%%%%%%%%%%%%%ledtest.c%%%%%%%%%%%%%%%%%%%%%%%

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