Req #49976 [Opn->Fbk]: Can't read anything from serial port

Edit report at https://bugs.php.net/bug.php?id=49976&edit=1 ID: 49976 Updated by: cmb@php.net Reported by: rpiccini at software4u dot it Summary: Can't read anything from serial port -Status: Open +Status: Feedback Type: Feature/Change Request -Package: *General Issues +Package: Streams related Operating System: * PHP Version: * -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: Is this still an issue with any of the actively supported PHP versions[1]? [1] <https://www.php.net/supported-versions.php> Previous Comments: ------------------------------------------------------------------------ [2011-04-22 21:59:22] beekerstudios at gmail dot com I struggled to find solutions to doing serial with php. I went so far as to do it in python, which I'm a novice at, but it brought to light why it wasn't working for me in php, my commands were just wrong. It's amazing how little documentation on it there is. Someone needs to do a good blog post about it. (looks at self) On to why my actually useful comment... Sleeping the script between fputs and fgets seems to do the job of resolving this. Yah it stalls the script a bit, but for the most part it's workable. It just means you can't constantly send messages to a device with serial commands. function sendSerialCommand($port,$command){ mode $port: BAUD=9600 PARITY=N data=8 stop=1 xon=off; $fp = fopen ($port.":", "r+"); if (!$fp) { echo "Uh-oh. Port not opened."; } else { if($command == "on"){ echo "Turning on.<br />"; $string = "\x2a\x70\x6f\x77\x3d\x6f\x6e\x23"; } else if($command == "off"){ echo "Turning off.<br />"; $string = "\x2a\x70\x6f\x77\x3d\x6f\x66\x66\x23"; } else if($command == "status"){ echo "Checking status.<br />"; $string = "\x2a\x70\x6f\x77\x3d\x3f\x23"; } fputs ($fp, $string); sleep(1); $response=""; while(!feof($fp)){ $response.=stream_get_contents($fp, 2); $lines=explode("\n",$response); } print_r($lines); fclose ($fp); } } sendSerialCommand("COM3","on") ------------------------------------------------------------------------ [2010-01-15 20:19:37] stash_85 at hotmail dot com I also have the same problem trying to connect to a gprs modem via serial port. I can send commands using fputs but the script hangs while trying to read from the resource using fgets, fread or stream_get_contents... I think the problem, at least in my case, is that the response doesn't have an end or something and the fact that the reading limit doesn't work in this case. The strange thing in my case is that back in 2007 i wrote an sms gateway using a GPRS modem and it used to work with fgets. The same script today, does not work. exec('mode com9 baud=9600 data=8 stop=1 parity=n xon=on'); $fd = fopen('COM9', "r+"); if ($fd){ stream_set_timeout($fd, 1); stream_set_blocking($fd, 0); fputs($fd, "AT\r"); $response=""; while(!feof($fd)){ $response.=stream_get_contents($fd, 2); // This will not work as it hangs the script here. // $response.=fread($fd, 2); // This will not work as it hangs the script here. // $response.=fgets($fd, 2); // This will not work as it hangs the script here. // $response.=fgets($fd); // This will not work as it hangs the script here. It used to work back in 2007. $lines=ereg_replace("\r","",$response); $lines=explode("\n",$lines); if (in_array("OK",$lines)) break; if (in_array("ERROR",$lines)) break; } print_r($lines); fclose($fd); } I managed to make it work using the php_dio extension on windows php 5.2.9. exec('mode com9 baud=9600 data=8 stop=1 parity=n xon=on'); $fd = dio_open('COM9', O_RDWR); if ($fd){ dio_write($fd, "AT\r"); $response=""; while(1){ $response.=dio_read($fd, 2); // $response.=dio_read($fd, 5); // This will not work as it hangs the script here. $lines=ereg_replace("\r","",$response); $lines=explode("\n",$lines); if (in_array("OK",$lines)) break; if (in_array("ERROR",$lines)) break; } print_r($lines); dio_close($fd); } RESULT: Array ( [0] => AT [1] => OK ) I hope i helped a bit with the above script. But please, someone has to resolve this bug. Those problems make people underestimate PHP... -- Christos. ------------------------------------------------------------------------ [2009-10-26 11:12:12] rpiccini at software4u dot it Thanks for reply, but binary mode doesn't help to make it works. On WIN XP and Ubuntu too nothing's changed. Anyway, I found a difference during fread instruction between WIN and Ubuntu that I haven't seen before (doesn't matter if binary mode is activated or not): [CODE] $buffer = fread($fp,128); //$buffer = fgets($fp); // tried also with fgets [/CODE] On WIN XP "fread" (and fgets too) hangs (never ending loop), while on UBUNTU $buffer is always empty (can't read reply from serial port) but the script doesn't loop on fread and goes (for the rest of my code) correctly to the end. It seems like "stream_set_blocking($fp,0)" doesn't work at all on WIN. By the way, I haven't yet solved my problem... ------------------------------------------------------------------------ [2009-10-25 20:23:06] jani@php.net Oops, and this of course: $fp = fopen('COM1:','rb+'); ------------------------------------------------------------------------ [2009-10-25 20:22:36] jani@php.net How about you open it in binary mode? Like this: $fp = fopen('/dev/ttyS0','rb+'); Might work bit better on windows..? ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=49976 -- Edit this bug report at https://bugs.php.net/bug.php?id=49976&edit=1