Python script won't run on PHP

Question

My goal is to write a string through the serial of my Raspberry Pi which will then be sent towards an Arduino and I'll read it through the Serial Monitor.

I got my Python script working and it works perfectly when I execute it on the Raspberry Pi's terminal. As soon as I run it through the website, it does not work.

To test it out, I made the PHP code run the script as soon as the site was launched. This is what the code looks like:

<?php

    exec('/usr/bin/python /var/www/UART3.py test');

?>

The test at the end of the exec() sends that string through the serial communication. I can copy and paste that code into the terminal and it works perfectly.

Things I have done:

• Tested the code individually (works)
• Gave rights to www-data by doing chmod +x UART3.py

Any ideas?

Answer 1

The answer was found thanks to @yamboy1 and finding this link: How to set a permission to call a Python script from PHP?

Basically, I had to give the correct privilege to the device itself. Instead of doing sudo chmod 777 /dev/ttyUSB0 like @Diego Dyan did, i did sudo chmod 777 /dev/ttyAMA0

So for people in the future, things to check:

• Does your program work individually? Compile it and run it by itself to check.

• Does your file have the correct privilege? In my case, the python code. If not, do sudo chmod +x file.py

• Does your device have the correct privilege? If not, do sudo chmod 777 /dev/ttyAMA0