Arduino返回错误的整数值

Question

我有一些代码，根据网站上的值（包含一个数字的空白页开启/关闭LED，页面上的数字表示LED应该闪烁的次数）

的问题是，循环继续运行。
我可以通过手动设置整数值（int c = 3）解决问题。

不知道我的问题是什么。
的，你是一个可以点我正确的方向

Ur L：http://b2b.as/lan.php?pid=8855

代码：

#include <Ethernet.h> 
#include <SPI.h> 

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; 
byte ip[] = { 192, 168, 1, 104 }; 
char server[] = "b2b.as"; 

void setup() 
{ 
    Ethernet.begin(mac, ip); 
    Serial.begin(9600); 

    delay(1000); 

    Serial.println(Ethernet.localIP()); 
    Serial.println(); 

    // Set digital pin as output 
    // 5V 
    pinMode(8, OUTPUT); 
} 

void loop() 
{ 

    // 
    Serial.print("\n-----\n"); 

    // Connect to the server 
    Serial.print("connecting to URL ..."); 

    // Start LAN connection 
    EthernetClient client; 
    if (client.connect(server, 80)) { 
    Serial.println("connected"); 
    client.println("GET /lan.php?pid=8855"); 
    client.println(); 
    } else { 
    Serial.println("connection failed"); 
    } 

    // Wait a moment for data to arrive 
    // Note: This is NOT a reliable way of doing this! 
    delay(1000); 

    if (client.available() > 0) { 

    char c = atoi(client.read()); 

    Serial.print("page value (pick): "); 
    Serial.print(c, DEC); 
    Serial.print("\n"); 

    for (int x = 1; x <= int(c); x++) { 
     Serial.print("picking: #"); 
     Serial.println(x); 
     digitalWrite(8, HIGH); 
     Serial.println("8 HIGH ..."); 
     delay(5000); // Add switch 
     digitalWrite(8, LOW); 
     Serial.println("8 LOW ..."); 
     delay(1000); 
    } 

    Serial.print("end"); 

    } 

    // Disconnect the client 
    if (client.connected()) { 
    //Serial.println(); 
    Serial.print("disconnecting"); 
    client.stop(); 
    } 

    // Wait another 9s, which will give us a delay of roughly 10s 
    delay(9000); 
} 

Answer 1

我假设调用lan.php?pid=8855将只返回值没有任何格式，例如HTML，XML，JSON。然后你的代码基本上将ASCII字符3转换为一个整数，它给你的整数值33（见ASCII Table）。因此，你的循环不会停止。

解决方案

只需使用atoi函数将其转换为整数。

char c = atoi(client.read()); 

Answer 2

看来，toInt（）是我正在寻找的功能。它将字符串转换为整数并修复循环。

https://www.arduino.cc/en/Reference/StringToInt

码已更新，它似乎工作：

#include <Ethernet.h> 
#include <SPI.h> 

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; 
byte ip[] = { 192, 168, 1, 104 }; 
char server[] = "b2b.as"; 

void setup() 
{ 
    Ethernet.begin(mac, ip); 
    Serial.begin(9600); 

    delay(1000); 

    Serial.println(Ethernet.localIP()); 
    Serial.println(); 

    // Set digital pin as output 
    // 5V 
    pinMode(8, OUTPUT); 
} 

void loop() 
{ 

    // 
    Serial.print("\n-----\n"); 

    // Connect to the server 
    Serial.print("connecting to URL ..."); 

    // Start LAN connection 
    EthernetClient client; 
    if (client.connect(server, 80)) { 
    Serial.println("connected"); 
    client.println("GET /lan.php?pid=8855"); 
    client.println(); 
    } else { 
    Serial.println("connection failed"); 
    } 

    // Wait a moment for data to arrive 
    // Note: This is NOT a reliable way of doing this! 
    delay(1000); 

    if (client.available() > 0) { 

    String pickNum; 

    while (client.available()) { 
     char c = client.read(); // gets one byte from serial buffer 
     pickNum += c; // count 
     delay(2); // delay for buffer 
    } 

    Serial.print("page value (pick): "); 
    Serial.println(pickNum); 

    for (int x = 1; x <= pickNum.toInt(); x++) { 
     Serial.print("picking: #"); 
     Serial.println(x); 
     digitalWrite(8, HIGH); 
     Serial.println("8 HIGH ..."); 
     delay(1000); // Add switch 
     digitalWrite(8, LOW); 
     Serial.println("8 LOW ..."); 
     delay(1000); 
    } 

    Serial.print("end"); 

    } 

    // Disconnect the client 
    if (client.connected()) { 
    //Serial.println(); 
    Serial.print("disconnecting"); 
    client.stop(); 
    } 

    // Wait another 9s, which will give us a delay of roughly 10s 
    delay(9000); 
}