我正在使用网络控制的漫游器并使用串行端口与
Arduino进行通信.我写了一些PHP,它只使用fwrite()并将ASCII 1或ASCII 2写入串行端口. Arduino正在听那个端口并根据它听到的内容做些什么.我知道我的PHP正在工作,因为无论何时我告诉它发送东西,Arduino都会收到它.这是Arduino代码:
//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() > 0) { //if there is anything on the serial port, read it
usbnumber = Serial.read(); //store it in the usbnumber variable
}
if (usbnumber > 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
}
}
所以这应该是相当直接的.现在,当我发送ASCII 1或ASCII 2时,我正在测试的LED(在引脚13上)打开并保持打开状态.但是,如果我发送另一个ASCII 1或2,它会关闭然后重新打开.目标是仅在ASCII 1是最后发送的东西时才打开它并保持打开直到最后发送的是2.
编辑:这是我的PHP:
<?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('???');
}
}
?>
<html>
<head><title>Rover Control</title></head>
<body>
<center><h1>Rover Control</h1><b>Version <?php echo $verz; ?></b></center>
<form method="post" action="<?php echo $PHP_SELF;?>">
<table border="0">
<tr>
<td></td>
<td>
</td>
<td></td>
</tr>
<tr>
<td>
<input type="submit" value="Stop" name="rcmd"><br/>
</td>
<td></td>
<td>
<input type="submit" value="Go" name="rcmd"><br />
</td>
</tr>
<tr>
<td></td>
<td><br><br><br><br><br>
</td>
<td></td>
</tr>
</table>
</form>
</body>
</html>
最佳答案 如果它是C,那么你在两个测试中都有赋值而不是比较,所以两者都是真的,所以所有的写操作都是每次都完成的.编译具有高警告级别(如GCC中的-Wall -pedantic).试试这个:
int a = 0;
if ( a == 1 ) printf( "a is not one: %d\n", a );
if ( a = 1 ) printf( "a is one: %d\n", a );
从您发布的PHP代码(我不是这里的专家)看起来您将二进制1编写为char,它不是ASCII 49,而是ASCII 1(soh),同样适用于2.尝试将其更改为“1”在PHP代码中(或C代码中的1)
这里有一篇关于Controlling the Serial Port with PHP的文章的链接 – 我用Google搜索,不知道它的质量 – 但看起来不足以将整数写入“com1” – 这超出了我的域名,所以祝你好运:)