Multi-platform serial port access convenience class
PHP Serial was written at a time where I did not know any other language than PHP and I started to get seriously bored with its abilities.
I somehow got hold of a « Citizen C2202-PD » point-of-sale display, and I wanted to play around with it. I also managed to get the documentation of it, and created a convenience class to access the serial port though the Linux file.
Afterwards, I posted it to PHP Classes, and this probably is what brought it any visibility.
<?php include 'PhpSerial.php'; // Let's start the class $serial = new PhpSerial; // First we must specify the device. This works on both linux and windows (if // your linux serial device is /dev/ttyS0 for COM1, etc) $serial->deviceSet("COM1"); // We can change the baud rate, parity, length, stop bits, flow control $serial->confBaudRate(2400); $serial->confParity("none"); $serial->confCharacterLength(8); $serial->confStopBits(1); $serial->confFlowControl("none"); // Then we need to open it $serial->deviceOpen(); // To write into $serial->sendMessage("Hello !");
Interestingly enough, this piece of code that is widely untested has created a lot if interest ever since it was created, and especially nowadays with everybody toying around with Arduinos and Raspberry Pis. I receive about 1 email every month asking for help with the code or sending patches/suggestions.
I think that it is time for me to remove the dust off this project and to give it a full visibility on modern tools, aka GitHub.
There is lots of bugs. I know there is. I just don't know which are they.
- Linux: the initially supported platform, the one I used. Probably the less buggy one.
- MacOS: although I never tried it on MacOS, it is similar to Linux and some patches were submitted to me, so I guess it is OK
- Windows: it seems to be working for some people, not working for some others. Theoretically there should be a way to get it done.
I have a few concerns regarding the behaviour of this code.
- Inter-platform consistency. I seriously doubt that all operations go the same way across all platforms.
- Read operations. Reading was never needed in my project, so all the tests I did on that matter were theoretic. I was also quite naive, so the API is probably not optimal. What we need is to re-think reading from scratch.
- Configuration done by calling functions. This is so Java. It would be much better to be able to pass a configuration array once and for all. Furthermore, I suspect that the order of call matters, which is bad.
- Auto-closing the device. There is an auto-close function that is registered at PHP shutdown. This sounds quite ridiculous, something has to be done about that.
- Use exceptions. Currently there is an heavy use of the errors system to report errors (2007 baby), but this is seriously lame. They have to be replaced by actual exceptions.
I have about 0 time to code or test this project. However, there is clearly a need for it.
As in all open-source projects, I need people to fit this to their needs and to contribute back their code.
What is needed, IMHO:
- Address the concerns listed above, and find new ones.
- Create a reproducible test environment for each OS, and prove that each feature works (basically, unit-testing).
- Report of use cases, bugs, missing features, etc.
If you feel like doing any of those, do not hesitate to create an issue or a pull-request, I'll gladly consider consider it :)
PHP Serial Copyright (C) 2007-2014 PHP Serial's contributors (see CONTRIBUTORS file)
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