Html/Php Code for turning on lights using Raspberry Pi not working

Question

So I have been working on a project to turn on/off LED lights remotely through my Raspberry Pi but I have run into an issue.

My index.html code should work properly but when I press the on or off button, nothing happens. The issue is not with the actual commands (sudo python /var/www/html/scripts/lights/lampon.py or sudo python /var/www/html/scripts/lights/lampoff.py) because when I run the same command directly in the raspberry pi terminal, it works. And the rest of my code also seems to be correct... So I don't know what the problem is.

The code looks like this:

<html>
<head>
<meta charset="UTF-8" />
<link rel="stylesheet" type="text/css" href="css/style.css">
</head>
<?php
if (isset($_POST['LightON']))
{
exec("sudo python /var/www/html/scripts/lights/lampon.py");
}
if (isset($_POST['LightOFF']))
{
exec("sudo python /var/www/html/scripts/lights/lampoff.py");
}
?>
<form method="post">
<button class="btn" name="LightON">Light ON</button>&nbsp;
<button class="btn" name="LightOFF">Light OFF</button><br><br>
</form>
</html>

Any help would be appreciated. Thanks in advance.

NOTE: I am able to run the sudo command above as a normal user and the lights work but when I press the button, it doesn't work (webpage seems to load - so its doing something... but the lights do not turn on).

I would imagine your php user does not have sudo permissions. I'm guessing when you run those commands directly on the terminal you are logged in as root or some other admin user? — DGS, Aug 28 '17 at 01:38
Possible duplicate of [How to call shell script from php that requires SUDO?](https://stackoverflow.com/questions/3166123/how-to-call-shell-script-from-php-that-requires-sudo) — sumit, Aug 28 '17 at 01:44
No... When I run the command, I do it as a normal user and it works... — user8450278, Aug 28 '17 at 20:32

score 0 · Answer 1 · answered Jun 07 '18 at 10:33

You can do it just like this:

 <html>
 <head>
 <meta name="viewport" content="width=device-width" />
 <title>LED Control</title>
 </head>
         <body>
         LED Control:
         <form method="get" action="gpio.php">
                 <input type="submit" value="ON" name="on">
                 <input type="submit" value="OFF" name="off">
         </form>
        <?php
         $setmode17 = shell_exec("/usr/local/bin/gpio -g mode 17 out");
         if(isset($_GET['on'])){
                 $gpio_on = shell_exec("/usr/local/bin/gpio -g write 17 1");
                 echo "LED is on";
         }
         else if(isset($_GET['off'])){
                 $gpio_off = shell_exec("/usr/local/bin/gpio -g write 17 0");
                 echo "LED is off";
         }
         ?>
         </body>
 </html>

But you need to install Wiring Pi on Raspberry Pi first, to install it :

$ sudo apt-get install git-core
$ git clone git://git.drogon.net/wiringPi
$ cd wiringPi
$ ./build

I hope that i was useful :)

score 0 · Answer 2 · answered Oct 16 '18 at 23:44

Well, that's the problem.

You are using PHP code inside a file called, "Index.html".

For PHP code to work it has to be in a file called, "Index.php".

The important part is that php code goes into files with an extension of .php and the same for html files.

Html/Php Code for turning on lights using Raspberry Pi not working

2 Answers2