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POArduino serial reading
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  1. POArduino serial reading
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    copied!<p>I am working on a web controlled rover and am using a serial port to communicate with an <a href="http://en.wikipedia.org/wiki/Arduino" rel="nofollow noreferrer">Arduino</a>. I wrote some PHP that just uses <code>fwrite()</code> and writes an ASCII 1 or an ASCII 2 to the serial port. The Arduino is listening to that port and does stuff based on what it hears. I know my PHP is working, because whenever I tell it to send stuff, the Arduino does receive it. Here is the Arduino code:</p> <pre><code>//This listens to the serial port (USB) and does stuff based on what it is hearing. int motor1Pin = 13; //the first motor's port number int motor2Pin = 12; //the second motor's port number int usbnumber = 0; //this variable holds what we are currently reading from serial void setup() { //call this once at the beginning pinMode(motor1Pin, OUTPUT); //Tell arduino that the motor pins are going to be outputs pinMode(motor2Pin, OUTPUT); Serial.begin(9600); //start up serial port } void loop() { //main loop if (Serial.available() &gt; 0) { //if there is anything on the serial port, read it usbnumber = Serial.read(); //store it in the usbnumber variable } if (usbnumber &gt; 0) { //if we read something if (usbnumber = 49){ delay(1000); digitalWrite(motor1Pin, LOW); digitalWrite(motor2Pin, LOW); //if we read an ASCII 1, stop } if (usbnumber = 50){ delay(1000); digitalWrite(motor1Pin, HIGH); digitalWrite(motor2Pin, HIGH); //if we read an ASCII 2, drive forward } usbnumber = 0; //reset } } </code></pre> <p>So this should be fairly straight forward. Right now, when I send either an ASCII 1 or an ASCII 2, the LED I am testing with (on pin 13) turns on and stays on. But, if I send another ASCII 1 or 2, it turns off and then turns back on. The goal is to have it turn on only if an ASCII 1 was the last thing sent and to stay on until a 2 was the last thing sent.</p> <p>Edit: Here's my PHP:</p> <pre><code>&lt;?php $verz="0.0.2"; $comPort = "com3"; /*change to correct com port */ if (isset($_POST["rcmd"])) { $rcmd = $_POST["rcmd"]; switch ($rcmd) { case Stop: $fp =fopen($comPort, "w"); fwrite($fp, chr(1)); /* this is the number that it will write */ fclose($fp); break; case Go: $fp =fopen($comPort, "w"); fwrite($fp, chr(2)); /* this is the number that it will write */ fclose($fp); break; default: die('???'); } } ?&gt; &lt;html&gt; &lt;head&gt;&lt;title&gt;Rover Control&lt;/title&gt;&lt;/head&gt; &lt;body&gt; &lt;center&gt;&lt;h1&gt;Rover Control&lt;/h1&gt;&lt;b&gt;Version &lt;?php echo $verz; ?&gt;&lt;/b&gt;&lt;/center&gt; &lt;form method="post" action="&lt;?php echo $PHP_SELF;?&gt;"&gt; &lt;table border="0"&gt; &lt;tr&gt; &lt;td&gt;&lt;/td&gt; &lt;td&gt; &lt;/td&gt; &lt;td&gt;&lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;input type="submit" value="Stop" name="rcmd"&gt;&lt;br/&gt; &lt;/td&gt; &lt;td&gt;&lt;/td&gt; &lt;td&gt; &lt;input type="submit" value="Go" name="rcmd"&gt;&lt;br /&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt;&lt;/td&gt; &lt;td&gt;&lt;br&gt;&lt;br&gt;&lt;br&gt;&lt;br&gt;&lt;br&gt; &lt;/td&gt; &lt;td&gt;&lt;/td&gt; &lt;/tr&gt; &lt;/table&gt; &lt;/form&gt; &lt;/body&gt; &lt;/html&gt; </code></pre>
 

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