Picture of Control an Arduino with PHP
Here's how to make your Arduino do things from over the internet without an ethernet or wifi shield. This is a simple way to make your project controllable from anywhere in the world!

Step 1: Platform Compatability

This method WILL NOT work under Windows. I can't tell you how long it took me to figure that out. The command we're using, fopen() is not implemented the same way under Windows and Linux, so you have to use Linux. Never used it before? Don't panic, it's not that bad.
DavidR239 months ago

i get stack errors when I press any button

brianfit1 year ago

Nice one. Was looking for help in writing to the serial port from a php sequence to trigger output on the Arduino, this was just the ticket. No Servos, I just needed buttons and LED response. Thanks, aloishis89!

DavidR23 brianfit9 months ago

any luck?

wyatt.jameson10 months ago

Everytime you open the serial port with $fp =fopen($comPort, "w");, you have to sleep(2); in order to allow the arduino time to boot up. It's pretty annoying, because you have to wait 2 seconds every time you send a command, but unless you can sustain the connection, you have to do that.

jelimoore1 year ago

So I'd (like) to assume this also works under OSX, too?

SorinMS1 year ago

I've fixed the problem.

I give Apache permission to use the serial port. I did this in terminal
with the following command:

sudo adduser www-data dialout

Once this is done, I restart Apache with the following terminal command:

sudo /etc/init.d/apache2 restart

SorinMS1 year ago

It doesn't work for me.

hi, this only works for me if i have the arduino serial monitor open. if i close it and try then php just hangs. do you know why this might be?
for me /dev/tty.usbETC.. only worked when the arduino serial monitor was open, but if i used /dev/cu.usbETC... then it worked always (mac 10.8.4)

And even THAT isn't working with me, I'm on Mac as well.

Apparently when there is no serial connection happening, the arduino goes to sleep and takes a while to reboot. Go here http://playground.arduino.cc/Main/DisablingAutoRes... for some solutions. I just used the capacitor going to ground.

lkokoszka1 year ago

Do I have to allow PHP permissions to do anything special? I have been working over many a code and still nothing comes out of php other than ls and simple commands.

put this code-> $PHP_SELF="your file php name";

after this code


$comPort = "com4"; /*change to correct com port */



$comPort = "com4"; /*change to correct com port */


Thanks for your help. I forgot I inquired about this issue. I actually got my code to work after changing some permissions on the usb device (making the specific USB port world writable). Probably not the most secure thing to do, but will also be ignoring escape characters or what not.

dmanovski1 year ago
Put code file on running. Web server and access it from web browser
sss1 year ago
very good tutorials that help me to create web application controller
thanks so much

very good tutorials that help me to find what I need to build a web based application and control from internet sensors Using Arduino board
Raphango2 years ago
Congratulations! I really appreciate your idea! When my just bought arduino arrives i'll try it!
ajindam2 years ago
For windows users, this code should do.

exec("mode COM3: BAUD=9600 PARITY=n DATA=8 STOP=1 to=off dtr=off rts=off");
$fp = fopen("COM3", "w");
fwrite($fp, "1"); //write string to serial
Thank you so much for posting this! I've been searching for a way to control a parallax propeller from a wamp server. This code got me up and running.
abubakr0222 years ago
where we have to put this code?