PHP - Reading COM Port from Windows

Question

The following is a library for serial communication through PHP: http://www.phpclasses.org/package/3679-PHP-Communicate-with-a-serial-port.html . The problem is that the readPort method is not fully implemented. It can read in * nix, but apparently not in Windows. Method:

/** * Reads the port until no new datas are availible, then return the content. * * @pararm int $count number of characters to be read (will stop before * if less characters are in the buffer) * @return string */ function readPort ($count = 0) { if ($this->_dState !== SERIAL_DEVICE_OPENED) { trigger_error("Device must be opened to read it", E_USER_WARNING); return false; } if ($this->_os === "linux") { $content = ""; $i = 0; if ($count !== 0) { do { if ($i > $count) $content .= fread($this->_dHandle, ($count - $i)); else $content .= fread($this->_dHandle, 128); } while (($i += 128) === strlen($content)); } else { do { $content .= fread($this->_dHandle, 128); } while (($i += 128) === strlen($content)); } return $content; } elseif ($this->_os === "windows") { /* Do nohting : not implented yet */ } trigger_error("Reading serial port is not implemented for Windows", E_USER_WARNING); return false; } 

The author declares:

==> /! \ WARNING /! \: it works with linux for r / w, but with windows I could only write work. If you are a windows user, try accessing the serial port over the network using serproxy instead.

The limitation of the PHP class library has already been mentioned in SO several times. I did not find a decent solution. Reading is a must for my application.

Does anyone know what to do?

Answer 1

If you can guarantee that you are on Windows, I could recommend an interesting approach: use COM (as in Microsoft COM, not in the serial port) or .NET.

There, the free .NET class that I regularly use is called CommStudio Express . I found it very reliable, but you can always use the standard SerialPort class built into .NET if you don't have to worry about accidentally disconnecting the USB-to-serial adapter .

In any case, it’s easy enough to get in a PHP .NET class with the DOTNET class :

 $serial = new DOTNET('system', 'System.IO.Ports.SerialPort'); $serial->PortName = 'COM3'; $serial->Open(); 

I have not tested this code (and not on Windows at the moment), but something like this should work fine. Then you can use all the usual .NET methods in PHP.

Answer 2

No, DOTNET freezes the COM port. You need to either restart the computer so that it detects again, or advanced users, as a rule, remove and install Arduino.