![]() ![]() Read one line from the file, then close it. Listing 1: A PHP script that reads data from the serial port and writes it to a file named "data.txt". Process 1: A script to continuously read the serial port and update a data file that is imported by the PHP webpage, see Listing 1. A solution to this is to split the process in two subprocesses: ![]() Furthermore, some Arduino-like systems may reset when the serial port is opened, making the setup useless. ![]() Data received outside this window is lost. And even if it did, it would mean that every time the browser requests the (latest version of the) page, the script would have to open the serial port, get some data and close the port again. This is the point where things become complicated because PHP doesn’t natively support serial ports. The PHP file then could also contain a script to read the data from the serial port. It is also possible to put the refresh tag in a PHP file instead of an HTML file and the browser will do the same thing. ![]() If we rewrite the page every ten seconds and put fresh serial data into it, then the browser will show it too. See the free download below this article. If we create a web page that includes this tag and point the browser to it, the latter will keep reloading it every ten seconds (the timeout can, of course, be another value). (In case your browser does not support this tag, it can be replaced by a piece of JavaScript. This tag tells the browser to reload the page containing the tag every ten seconds. ![]()
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