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Tutorial Video
Hardware
- PHPoC Blue (+ USB WLAN) or PHPoC Black (+ Ethernet cable)
- Micro USB to USB Cable (to upload source code to PHPoC Device)
About Built-in LED
There are some LEDs are built-in on PHPoC board. This helps user quickly get started without wiring anything. These LED were already connected to IO pin of PHPoC device.
How to control built-in LED:
- These LEDs are turned ON by setting IO pin of PHPoC device to LOW (0 V).
- These LEDs are turned OFF by setting IO pin of PHPoC device to HIGH (3.3 V).
Quick Steps
Source code of this example is a part of PHPoC Support Packet (PSP). You need to:
- Download PHPoC Support Package.
- Upload example\p4s\02.html_text\01.uio_ob_led to PHPoC Blue/Black.
- Configure network parameters (e.g. WiFi SSID, password, IP address ...).
- Access webpage on PHPoC using Web Browser on your PC or smart phone (See How To).
Source Code
Source files includes:index.php file, which contains source code of web page. It is only run in response to request from Web Browser.
index.php
[Full Code]
PHP Code:
<html>
<head>
<title>PHPoC / <?echo system("uname -i")?></title>
<meta name="viewport" content="width=device-width, initial-scale=0.7">
<style> body { text-align: center; } </style>
</head>
<body>
<h2>
UIO / On-Board User LED<br>
<br>
<?php
include_once "/lib/sd_340.php";
define("OUT_PIN", 30);
uio_setup(0, OUT_PIN, "out");
if(($led0 = _GET("led0")))
{
if($led0 == "low")
uio_out(0, OUT_PIN, LOW);
else
uio_out(0, OUT_PIN, HIGH);
}
if(uio_in(0, OUT_PIN) == LOW)
{
echo "LED0 Status : ON<br>\r\n";
echo "<br><a href='index.php?led0=high'>Toggle</a><br>\r\n";
}
else
{
echo "LED0 Status : OFF<br>\r\n";
echo "<br><a href='index.php?led0=low'>Toggle</a><br>\r\n";
}
?>
</h2>
</body>
</html>
[Explanation]
Source code of index.php file is composed of HTML, CSS and PHPoC code.
PHPoC code is interpreted on on PHPoC device.
-
PHP Code:
<?php
include_once "/lib/sd_340.php";
define("OUT_PIN", 30);
uio_setup(0, OUT_PIN, "out");
if(($led0 = _GET("led0")))
{
if($led0 == "low")
uio_out(0, OUT_PIN, LOW);
else
uio_out(0, OUT_PIN, HIGH);
}
if(uio_in(0, OUT_PIN) == LOW)
{
echo "LED0 Status : ON<br>\r\n";
echo "<br><a href='index.php?led0=high'>Toggle</a><br>\r\n";
}
else
{
echo "LED0 Status : OFF<br>\r\n";
echo "<br><a href='index.php?led0=low'>Toggle</a><br>\r\n";
}
?>
- Setup IO pin to output mode.
- Get the requested state from HTTP request.
- Control the state of built-in LED according to the requested state.
- Read the current state of built-in LED .
- Print out the current state to webpage.
- Print out hyperlink, which can be used to toggle state of built-in LED to webpage.
PHPoC code may add/update the content of HTML, CSS or JavaScript code. Once PHPoC code is interpreted in PHPoC, the remaining code is client-side code and it is returned to Web Browser. Web Browser receives this code and interpret it to display the webpage.
- HTML: describes the structure of Web pages
- CSS: describes how HTML elements are to be displayed
See Also
- LED - Blinking LED.
- LED - Controlling LED from Webpage with Image.
- LED - Controlling Buzzer via WebSocket.
Other Resources